Experimentation has been the cornerstone of much of integrated pest management (IPM) research. Here, we aim to open a discussion on the possible merits of expanding the use of observational studies, and in particular the use of data from farmers or private pest management consultants in “ecoinformatics” studies, as tools that might complement traditional, experimental research. The manifold advantages of experimentation are widely appreciated: experiments provide definitive inferences regarding causal relationships between key variables, can produce uniform and high-quality data sets, and are highly flexible in the treatments that can be evaluated. Perhaps less widely considered, however, are the possible disadvantages of experimental research. Using the yield-impact study to focus the discussion, we address some reasons why observational or ecoinformatics approaches might be attractive as complements to experimentation. A survey of the literature suggests that many contemporary yield-impact studies lack sufficient statistical power to resolve the small, but economically important, effects on crop yield that shape pest management decision-making by farmers. Ecoinformatics-based data sets can be substantially larger than experimental data sets and therefore hold out the promise of enhanced power. Ecoinformatics approaches also address problems at the spatial and temporal scales at which farming is conducted, can achieve higher levels of “external validity,” and can allow researchers to efficiently screen many variables during the initial, exploratory phases of research projects. Experimental, observational, and ecoinformatics-based approaches may, if used together, provide more efficient solutions to problems in pest management than can any single approach, used in isolation.

The use of mixtures of transgenic insecticidal seed and nontransgenic seed to provide an in-field refuge for susceptible insects in insect-resistance-management (IRM) plans has been considered for at least two decades. However, the U.S. Environmental Protection Agency has only recently authorized the practice. This commentary explores issues that regulators, industry, and other stakeholders should consider as the use of biotechnology increases and seed mixtures are implemented as a major tactic for IRM. We discuss how block refuges and seed mixtures in transgenic insecticidal corn, Zea mays L., production will influence integrated pest management (IPM) and the evolution of pest resistance. We conclude that seed mixtures will make pest monitoring more difficult and that seed mixtures may make IRM riskier because of larval behavior and greater adoption of insecticidal corn. Conversely, block refuges present a different suite of risks because of adult pest behavior and the lower compliance with IRM rules expected from farmers. It is likely that secondary pests not targeted by the insecticidal corn as well as natural enemies will respond differently to block refuges and seed mixtures.

Ozone is a powerful oxidant capable of killing insects and microorganisms, and eliminating odors, taste, and color. Thus, it could be useful as a fumigant to decontaminate honey comb between uses. The experiments here are intended to determine the exposure levels required to kill an insect pest and spore forming bee pathogens. Ozone was effective against greater wax moth, Galleria mellonella (L.) (Lepidoptera: Pyralidae), even on naturally infested comb. Neonates and adults were the easiest life stages to kill, requiring only a few hours of exposure, whereas eggs required a 48-h exposure (at 460–920 mg O₃/m³). Two honey bee, Apis mellifera L. (Hymenoptera: Apidae), pathogens, Ascosphaera apis (a fungus that causes chalkbrood) and Paenibacillus larvae (a bacterium that causes American foulbrood), also were killed with ozone. These pathogens required much higher concentrations (3,200 and 8,560 mg O₃/m³, respectively) and longer exposure periods (3 d) than needed to control the insects. P. larvae was effectively sterilized only when these conditions were combined with high temperature (50°C) and humidity (≥75% RH). Thus, ozone shows potential as a fumigant for bee nesting materials, but further research is needed to evaluate its acceptability and efficacy in the field. The need for a reliable method to decontaminate honey bee nesting materials as part of an overall bee health management system is discussed.

Phytoplasmas are phloem-restricted plant pathogens transmitted by leafhoppers, planthoppers, and psyllids (Hemiptera). Most known phytoplasma vectors belong to the Cicadellidae, but many are still unknown. Within this family, Empoasca spp. (Typhlocybinae) have tested positive for the presence of some phytoplasmas, and phytoplasma transmission has been proven for one species. The aim of this work was to investigate the ability of Empoasca decipiens Paoli in transmitting chrysanthemum yellows phytoplasma (CYP, “Candidatus Phytoplasma asteris”, 16SrI-B) and Flavescence dorée phytoplasma (FDP, 16SrV-C) to Chrysanthemum carinatum Schousboe (tricolor daisy) and Vicia faba (L.) (broad bean). Euscelidius variegatus Kirschbaum, a known vector of CYP and FDP, was caged together with Em. decipiens on the same source plants as a positive control of acquisition. Em. decipiens acquired CYP from daisies, but not from broad beans, and inoculated the pathogen to daisies with a low efficiency, but not to broad beans. Em. decipiens did not acquire FDP from the broad bean source. Consistent with the low transmission rate, CYP was found in the salivary glands of very few phytoplasma-infected Em. decipiens, indicating these organs represent a barrier to phytoplasma colonization. In the same experiments, the vector Eu. variegatus efficiently acquired both phytoplasmas, and consistently CYP was detected in the salivary glands of most samples of this species. The identity of the CYP strain in leafhoppers and plants was confirmed by polymerase chain reaction (PCR) -restriction fragment length polymorphism. The CYP titer in Em. decipiens was monitored over time by real-time PCR. The damage caused by Em. decipiens feeding punctures was depicted. Differences in feeding behavior on different plant species may explain the different phytoplasma transmission capability. Em. decipiens proved to be an experimental vector of CYP.

Almond leaf scorch (ALS) disease is caused by the bacterium Xylella fastidiosa and transmitted by xylem-feeding insects. Reports of increased incidence of ALS-diseased trees in California prompted surveys in three almond [Prunus dulcis (Mill.) D.A. Webb]-growing regions, from June 2003 to September 2005, to determine insect vector species composition and abundance. For comparison, sampling in and near vineyards in the San Joaquin Valley, California, also was completed. Sampling in or near almond orchards collected >42,000 Cicadomorpha of which 4.8% were xylem feeders, including 1,912 grass sharpshooter, Draeculacephala minerva Ball; five Xyphon fulgida Nottingham; and a single spittlebug, Philaenus spumarius L. The most abundant vector was D. minerva. Season-long sampling indicated that D. minerva was a year-round resident in and/or near almonds in the Sacramento Valley, but not in the San Joaquin Valley. Similarly, D. minerva was rare in vineyards in the San Joaquin Valley, but was abundant in irrigated pastures near vineyards. D. minerva was most frequently collected along orchard margins, and peak densities were observed in summer, the period of time when bacterial titers are reported to increase in infected trees. Screening of D. minerva for presence of X. fastidiosa found that 1.1% of insects collected near almond orchards and 4.5% of insects collected from pastures tested positive. The X. fastidiosa subspecies and genotype detected in insects collected from orchards matched those collected from ALS-diseased almond trees in the same orchard. Of the few X. fulgida and P. spumarius collected, none tested positive for X. fastidiosa. Results are discussed with respect to X. fastidiosa vector control and detection methods.

We identified acaricidal compounds in Inula japonica Thunberg (Asteraceae) that were effective against carmine spider mite, Tetranychus cinnabarinus (Boisduval). Petroleum-ether extracts from I. japonica were toxic to T. cinnabarinus, with a 50% lethal concentration (LC₅₀) value of 1.18 mg/ml. Silica gel column chromatography was used to separate the acaricidal components. Seventeen of 38 fraction groups had mite mortality rates >50%, nine fraction groups had rates >60%, and three fraction groups had rates >80% at 2 mg/ml. The major volatile compounds in the bioactive fraction groups were identified by gas chromatography-mass spectroscopy, and β-sitosterol (1), stigmasterol (2), lupeol (3), and α-amyrin (4) were identified and determined to have acaricidal activity against T. cinnabarinus in vitro.

Spathius agrili Yang (Hymenoptera: Braconidae) can be successfully reared on emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), larvae feeding in chambers drilled in small ash twigs that are wrapped with floral tape. Females maintained in groups with males for one week can receive enough sperm for production of female progeny throughout their lives. Volatiles released by emerald ash borer adults feeding on ash foliage increased parasitoid fecundity over ash foliage alone or no stimulus. The temperature at which the parasitoids were reared ranged from 20 to 25°C in a daily cycle; however, raising the daily maximum temperature to 28°C did not affect parasitoid longevity or fecundity. Adult females lived between 12 and 127 d, with an average of 60.8 ± 4.5 d. Males lived slightly longer, with an average of 66 ± 4.5 d. The first clutch of eggs was laid when the female was between 2 and 42 d old, with the average preoviposition period lasting 11.4 ± 1.4 or 19.5 ± 2.0 d in 2007 and 2009 trials, respectively. A higher proportion of the emerald ash borer larvae were feeding and thus attractive to parasitoids in the 2009 trial, and female S. agrili laid an average of 9.5 ± 1.0 clutches containing 5.4 ± 0.2 eggs, for an average of 51.2 eggs per female. Approximately three quarters of the progeny were female. The number of eggs per clutch was significantly greater when deposited on larger emerald ash borer larvae, further highlighting the need for quality larvae in rearing. Chilling S. agrili pupae at 10°C to stockpile them for summer release was not successful; chilling resulted in lower survival and lower fecundity of emerging progeny. Female S. agrili proved capable of attacking emerald ash borer larvae through even the thickest bark of an ash tree that was 30-cm diameter at breast height. Even emerald ash borer larvae that were creating overwintering chambers in the outer sapwood of the tree were successfully attacked, suggesting that S. agrili could be reared on field collected logs infested with emerald ash borer.

Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) is sporadically captured in the Rio Grande Valley of Texas. Although its preferred hosts are in the Sapotaceae family, several varieties of Citrus, including grapefruit and oranges are listed as alternate hosts. Although Mexican fruit fly, Anastrepha ludens (Loew), is known to be a major pest of Citrus, doubt exists as to the status of Citrus as a breeding host for A. serpentina. To evaluate the host status of commercial Citrus for A. serpentina we compared oviposition and development with that of A. ludens under laboratory conditions with ‘Rio Red’ grapefruit (Citrus paradisi MacFayden) and ‘Valencia’ oranges [Citrus sinensis (L.) Osbeck] in different stages of maturity. Both fly species oviposited in early season fruit in which the eggs and larvae died in the fruit albedo. Survival of either species to the adult stage occurred in later season grapefruit. In oranges, no A. serpentina larvae survived compared with 150 A. ludens surviving to adults. Survival on both Citrus species was much lower for A. serpentina, only ≈ 5% of eggs eclosed into larvae in grapefruit compared with ≈50% for A. ludens. In oranges ≈16% of A. serpentina eggs eclosed compared with ≈76% for A. ludens. In grapefruit, only one fourth as many A. serpentina larvae survived to the adult stage compared with A. ludens. Additional experiments were performed in a greenhouse on small, caged trees of la coma (Sideroxylon celastrinum H.B.K.), a Texas species of Sapotaceae. The A. serpentina females readily oviposited into these berries and normal adults emerged. The present low incidence of the adults, coupled with the high mortality during development of the larvae, suggests that Texas citrus is unlikely to support a breeding population of A. serpentina.

Nonchemical, environmentally friendly quarantine treatments are preferred for use in postharvest control of insect pests. Combined high temperature and controlled atmosphere quarantine treatments for phytosanitary fruit pests Macchiademus diplopterus (Distant) (Hemiptera: Lygaeidae) and Phlyctinus callosus (Schöenherr) (Coleoptera: Curculionidae) were investigated to determine the potential of such treatments for quarantine security. Field-collected, aestivating M. diplopterus adults and P. callosus adults were treated using a controlled atmosphere waterbath system. This system simulates the controlled atmosphere temperature treatment system (CATTS) used to control a number of phytosanitary pests in the United States and allows for a rapid assessment of pest response to treatment. Insects were treated under regular air conditions and a controlled atmosphere of 1% oxygen, 15% carbon dioxide in nitrogen, at two ramping heat rates, 12 and 24°C/h. Treatment of both species was more effective under both heating rates when the controlled atmosphere condition was applied. Under these conditions of controlled atmospheres, mortality of P. callosus was greater when the faster heating rate was used, but the opposite was true for M. diplopterus. This could be due to the physiological condition of aestivation contributing to metabolic arrest in response to the stresses being applied during treatment. Results indicate that the potential for the development of CATTS treatments for these phytosanitary pests, particularly P. callosus, is promising.

Systemic activity of the neonicotinoids clothianidin, dinotefuran, and thiamethoxam and the anthranilic diamide chlorantraniliprole was tested against adult black vine weevils, Otiorhynchus sulcatus (F.) (Coleoptera: Curculionidae), on Astilbe, Euonymus, Heuchera, Rhododendron, Sedum, and Taxus. Insecticide treatments were applied to the soilless substrate of containerized plants. Bioassays were conducted 12 or 13, 26, and 42 d after treatment (DAT) and ran for 7 d; and feeding, mortality, and weight gain or loss by weevils were evaluated. Foliage was removed from test plants and then placed in arenas with adult black vine weevils. The neonicotinoids reduced feeding and weight gain by adult black vine weevils on most plant species with residual activity 42 DAT on some plant species. At 12 DAT, mortality was caused by the three neonicotinoids on Astilbe and by thiamethoxam on Sedum; and at 26 DAT dinotefuran caused mortality on Astilbe. Chlorantraniliprole reduced feeding on Taxus at 12 DAT, with no activity detected in other bioassays. Another set of bioassays was conducted to examine survival and fecundity of adult black vine weevils during prolonged feeding on Heuchera and Taxus systemically treated with dinotefuran or thiamethoxam. Bioassay procedures were similar to those described above, except they ran continuously for 56 d. Prolonged feeding on dinotefuran and thiamethoxam treated Heuchera and Taxus resulted in high mortality of adult black vine weevils and reduced fecundity. These studies show that the systemic activity of neonicotinoids is influenced by plant species and that systemic neonicotinoids have the potential to suppress black vine weevil populations in containerized nursery crops.

Fumigant activity of 34 commercial essential oils was assessed on female adults and eggs of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) at three temperatures (5, 15, and 25°C). Common thyme, cinnamon, and lemongrass oils were equally effective on twospotted spider mite adults showing 85.8–100% mortality at 5 and 10 µl/liter air at 25°C. At a lower temperature of 15°C, lemongrass and peppermint resulted in ≥90% mortality of adults at 10 µl/liter air. Only lemongrass was relatively active at 5 µl/liter air, at 15°C. At 5°C, lemongrass and peppermint caused significantly higher adult mortality than controls but only at 10 µl/liter air. Common thyme oil showed the highest ovicidal activity at 5 µl/liter air at 25°C. Among the main components of common thyme and lemongrass oils, citral was lethal to twospotted spider mite adults at all tested temperatures. Carvacrol, thymol, and citral caused the same inhibitory effects on the hatch of twospotted spider mite eggs at 25°C. However, citral was more active than other compounds to twospotted spider mite eggs at 15°C. Therefore, we conclude that citral has the best potential for development as a fumigant against twospotted spider mite on agricultural products harvested late in the growing season.

The sterile insect technique (SIT) is widely used for suppressing or eradicating target pest insect populations. In the eradication programs using the SIT, a large number of sterile insects are marked and released in the field. In Japan, Cylas formicarius (F.) group (Coleoptera: Brentidae) weevils are marked with a fluorescent powder dye to monitor the progress of such programs. However, this monitoring technique is not fully effective because of the disappearance or contamination of the dye. Therefore, an alternative marking method is required. Currently, a rare color morph such as piceous elytra (PE) is used for visible marking of C. formicarius group weevils. A PE-monomorphic strain has previously been established by artificial selection from a small locally distributed population; this can lead to reduced survival and genetic changes in behavioral traits due to inbreeding depression. In this study, we evaluated the survival rate and mating behavior of PE males of C. formicarius group. The characteristics of the PE males were similar to those of the wild strain (WS) males. Thus, we considered that PE males were suitable for visible marking in the eradication programs using the SIT.

This study examined soil cation concentration gradients around decomposing logs and determined whether Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) builds galleries in soil substrates containing those cations versus soils without, presumably in an effort to forage efficiently. Soil samples were collected at different depths and lateral distances from decomposing logs containing termites, freshly fallen logs without termites, and bare soil locations at 10 sites to determine whether cation gradients existed in a forest floor. Analyses of cation gradients were significant for potassium, calcium, and magnesium; however, only potassium showed a significant gradient where concentrations decreased with depth and lateral distance from a decomposing log. R. flavipes was then tested in laboratory bioassays to determine if they were attracted to salt cation solutions. Linear foraging distance was significantly greater in artificial K₂CO₃ gradients than in controls. The results from this study suggest that potassium is found in gradients around decomposing logs and that R. flavipes is attracted to this cation.

Trap designs for banana root borer, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), have been done essentially on the understanding that C. sordidus rely primarily on chemical cues. Our present results indicate that these borers also rely on visual cues. Previous studies have demonstrated that among the eight differently colored traps tested in the field, brown traps were the most effective compared with the performances of yellow, red, gray, blue, black, white, and green traps; mahogany-brown was more effective than other shades of brown. In the current study, efficiency of ground traps with different colors was evaluated in the laboratory for the capture of C. sordidius. Response of C. sordidus to pheromone-baited ground traps of several different colors (used either individually or as 1:1 mixtures of two different colors) were compared with the standardized mahogany-brown traps. Traps with mahogany-brown mixed with different colors had no significant effect. In contrast, a laboratory color-choice tests indicated C. sordidus preferred black traps over other color traps, with no specific preferences for different shades of black. Here again, traps with black mixed with other colors (1:1) had no influence on the catches. Therefore, any other color that mixes with mahogany-brown or black does not cause color-specific dilution of attractiveness. By exploiting these results, it may be possible to produce efficacious trapping systems that could be used in a behavioral approach to banana root borer control.

Effects of rearing density, adult density and sex ratio in the flight chamber, adult age, sex, presence or absence of food, and duration of food deprivation on rate of and time to flight initiation of the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), were studied in the laboratory. Rates of flight initiation were slightly lower at lower rearing densities, but they did not differ with age or sex of adults, presence or absence of food in the flight chamber, or duration of food deprivation. Focal adults were less likely to fly when individuals of the opposite sex were present in flight chambers. Presence of the same sex or mixed sexes and numbers of individuals in flight chambers did not affect tendency to fly of focal individuals. Mean time to flight of older beetles (7–20 d old) was less than that of younger beetles (1–4 d old). No young beetles flew during the first 24 h of flight tests. Mean time to flight did not differ with rearing density, sex, presence or absence of food, or duration of food deprivation. Our results indicate that this species is highly dispersive during the adult stage and that flight does not seem to be associated with just prereproductive or postreproductive dispersal phases, high rearing density, or short to medium periods of food deprivation. Therefore, T. castaneum level of flight activity does not seem to be associated with factors that have been shown in the literature to increase dispersal by walking for this species and to increase flight initiation in other stored-product species.

An important component in the Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae), eradication program is bait spray application to knock down localized A. ludens infestations enhancing the sterile to wild fly ratio and increasing the effectiveness of the sterile insect release program. Efficacy tests were conducted using spray equipment that applies ultralow application rates of malathion NU-LURE or GF-120 spinosad by ground into citrus. Trapit Dome traps located in fields treated with malathion NU-LURE and GF-120 spinosad high rate caught significantly fewer flies than the control in all replications. Treatments reduced the Mexican fruit fly populations by 99.1 and 92.5% with malathion and 98.2 and 89.9% with GF-120 spinosad high rate. Traps in plots with lower rates of GF-120 reduced fly populations by 76.3 and 74.3% in winter and summer test, respectively. There was no indication of fly repulsion from either malathion or GF-120 spinosad during this test. The bait spray option using ground spray equipment to apply ultra-low rates of either malathion NU-LURE or GF-120 spinosad high rate is a viable cost effective treatment method to treat small acreages for A. ludens. For organic growers, the ground spray equipment is effective in applying GF-120 spinosad at the labeled rates.

Large-scale cultivation of plants used as biofuels is likely to alter the ecological interactions of current agricultural crops and their insect pests in a myriad of ways. Recent evidence suggests many contemporary maize pests will be able to use potential biofuel crops such as switchgrass, Panicum virgatum L., and miscanthus as hosts. To determine how suitable these biofuels are to the maize, Zea mays L., pest and generalist graminivore, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), we examined host plant preference and larval performance on foliage grown for commercial biofuel production. Larvae fed leaf tissue from both field- and greenhouse-grown switchgrass and miscanthus were monitored for survival, development, and food use relative to field-grown maize. Survivorship on biofuel crops was high on greenhouse-grown leaf tissue but severely reduced for field-grown switchgrass, and no larvae survived on field-grown miscanthus. Larvae fed field-grown tissue had larger head capsules yet achieved lower pupal weights because the increased toughness of the leaf tissue prevented the assimilation of nitrogen. Given that larvae overwhelmingly preferred maize to other biofuel crop species and that survival and performance were dramatically reduced on biofuel crop species, it is likely that biofuel crops, as grown for field cultivation, will suffer reduced damage from maize pests such as S. frugiperda because of reduced suitability.

The springtail, Sminthurus viridis (L.) (Collembola: Sminthuridae), is an important agricultural pest across southern Australia. We investigated the seasonal abundance patterns and summer diapause response of S. viridis in southeastern Australia by using field and shadehouse (a greenhouse that offers seedlings shade) experiments. Seasonal activity patterns of S. viridis were largely consistent with previous studies, with the pest active from autumn to spring. In addition, the timing and pattern of the summer-diapausing egg stage was established, with multiple generations probably producing diapause eggs. A strong relationship between soil moisture and temperature with autumn emergence also was observed. These results suggest that S. viridis autumn pest pressure can be predicted and indicate that late-season spraying strategies currently used for a sympatric agricultural pest are unlikely to be as effective against S. viridis.

Feeding by lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae), larvae on sugarcane (a complex hybrid of Saccharum spp.) causes leaf damage, dead hearts, and dead plants that can result in stand and yield loss. A 2-yr greenhouse experiment was conducted to examine sugarcane variety and plant age-specific feeding responses to E. lignosellus. Plants growing from single-eye setts of three varieties were exposed to a single generation of E. lignosellus larvae beginning at the three-, five-, and seven-leaf stages. Results indicated that the physical damage and resulting yield loss of plants attacked by E. lignosellus larvae were dependent on the variety and leaf stage at which they were infested. Significantly more plant damage was observed in all three varieties when infested at the three- than at the seven-leaf stage. Larvae caused significantly more plant damage and reduced yield in CP 89-2143 than in CP 78-1628. Tiller production increased in CP78-1628 and CP 88-1762 when infested at the three-leaf stage, whereas tiller production, biomass and sugar yield decreased in CP 89-2143 when infested at all leaf stages, compared with the untreated control. There was no reduction in yield when CP 78-1628 was infested at the three- or five-leaf stages. Biomass was reduced in CP 88-1762 when plants were infested at any of the leaf stages, but sugar yield was reduced only when infested at the seven-leaf stage. These results indicate that compensation in response to E. lignosellus damage was variety dependent and declined with the delay in infestation time.

Black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), is an occasional pest of maize (corn), Zea mays L., that may cause severe stand losses and injury to corn seedlings. The efficacy of the neonicotinoid seed treatment clothianidin at two commercially available rates and their interaction with a transgenic corn hybrid (Bt corn), trait expressing the Bacillus thuringiensis variety aizawai insecticidal toxin Cry 1Fa2, against black cutworm larvae was investigated. Clothianidin at a rate of 25 mg kernel^-1 on Bt corn increased larval mortality and reduced larval weight gains additively. In contrast, weights of larvae fed non-Bt corn seedlings treated with clothianidin at a rate of 25 mg kernel^-1 increased significantly, suggesting either compensatory overconsumption, hormesis, or hormoligosis. Both Bt corn alone and clothianidin at a rate of 125 mg kernel^-1 applied to non-Bt corn seedlings caused increased mortality and reduced larval weight gains. In two field trials, plots planted with Bt corn hybrids consistently had the highest plant populations and yields, regardless of whether they were treated with clothianidin at the lower commercial rate of 25 mg kernel^-1 The use of Bt corn alone or in combination with the low rate of clothianidin (25 mg kernel^-1) seems suitable as a means of suppressing black cutworm in no-tillage cornfields, although rescue treatments may still be necessary under severe infestations. Clothianidin alone at the low rate of 25 mg kernel^-1 is not recommended for black cutworm control until further studies of its effects on larval physiology and field performance have been completed.

We tested different pheromone-baited traps for surveying winter moth, Operophtera brumata (L.) (Lepidoptera: Geometridae), populations in eastern North America. We compared male catch at Pherocon 1C sticky traps with various large capacity traps and showed that Universal Moth traps with white bottoms caught more winter moths than any other trap type. We ran the experiment on Cape Cod, MA, where we caught only winter moth, and in western Massachusetts, where we caught only Bruce spanworm, Operophtera bruceata (Hulst) (Lepidoptera: Geometridae), a congener of winter moth native to North America that uses the same pheromone compound [ (Z,Z,Z)-1,3,6,9 -nonadecatetraene] and is difficult to distinguish from adult male winter moths. With Bruce spanworm, the Pherocon 1C sticky traps caught by far the most moths. We tested an isomer of the pheromone [ (Z,Z,Z) -1,3,6,9-nonadecatetraene] that previous work had suggested would inhibit captures of Bruce spanworm but not winter moths. We found that the different doses and placements of the isomer suppressed captures of both species to a similar degree. We are thus doubtful that we can use the isomer to trap winter moths without also catching Bruce spanworm. Pheromone-baited survey traps will catch both species.

The exotic redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), and its fungal symbiont Raffaellea lauricola Harrington, Fraedrich, and Aghayeva are responsible for widespread redbay, Persea borbonia (L.) Spreng., mortality in the southern United States. Effective traps and lures are needed to monitor spread of the beetle and for early detection at ports-of-entry, so we conducted a series of experiments to find the best trap design, color, lure, and trap position for detection of X. glabratus. The best trap and lure combination was then tested at seven sites varying in beetle abundance and at one site throughout the year to see how season and beetle population affected performance. Manuka oil proved to be the most effective lure tested, particularly when considering cost and availability. Traps baited with manuka oil lures releasing 5 mg/d caught as many beetles as those baited with lures releasing 200 mg/d. Distributing manuka oil lures from the top to the bottom of eight-unit funnel traps resulted in similar numbers of X. glabratus as a single lure in the middle. Trap color had little effect on captures in sticky traps or cross-vane traps. Funnel traps caught twice as many beetles as cross-vane traps and three times as many as sticky traps but mean catch per trap was not significantly different. When comparing height, traps 1.5 m above the ground captured 85% of the beetles collected but a few were caught at each height up to 15 m. Funnel trap captures exhibited a strong linear relationship (r² = 0.79) with X. glabratus attack density and they performed well throughout the year. Catching beetles at low densities is important to port of entry monitoring programs where early detection of infestations is essential. Our trials show that multiple funnel traps baited with a single manuka oil lure were effective for capturing X. glabratus even when no infested trees were visible in the area.

Glenea cantor (F.) (Coleoptera: Cerambycidae: Lamiinae) is an Asian longicorn beetle whose larvae bore under the bark of living trees of at least seven plant families and enter the wood for pupation. Here, we determined the phenology of this beetle on its natural host, kapok [Bombax ceiba L. = Gossampinus malabaricus (DC.) Merr], in an uncontrolled insectary at ambient environmental conditions, and we compared the efficiency of four larval rearing procedures at 25 ± 2°C, 75 ± 5% RH, and a photoperiod of 14:10 (L:D) h in the laboratory. It had five generations, including an overwintering generation, a year in southern China, with overlaps between generations and no diapause. Adults were present in early March—early December; eggs in early April—early December; larvae almost year-round, and pupae in mid-February—mid-April as well as mid-May—late November. All larvae of the overwintering generation and the larvae of the fourth generation that hatched in and after mid-November overwintered. The longevity of females and males was 71.94 ±1.21 d and 46.87 ± 1.11 d, respectively, and mean fecundity was 106.65 ±3.61 eggs. Four larval rearing procedures using kapok twigs were tested: 1) 10 neonate larvae were left in the original host twig, 2) 10 neonate larvae were removed from the original bark and transferred to a new host twig, 3) 10 neonate larvae embedded in the original bark were transferred to a new host twig, and 4) a single neonate larva embedded in the original bark was transferred to a new host twig. We observed the survival of 300 neonate larvae for each rearing procedure. Approximately 81–85% of neonate larvae successfully developed to adult stage when neonate larvae were transferred together with the original bark to new host twigs; when neonate larvae were transferred without the original bark, only ≈38% of the inoculants became adults, and when larvae were left in original twigs, ≈52% of them reached adult stage. Resulting adults from different rearing methods and collected from the field had similar body weight and sex ratio. In terms of time, labor, and the number of resulting adults, procedure 3 is the most effective method for maintaining a laboratory colony.

Improved detection tools are needed for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive forest insect from Asia that has killed millions of ash (Fraxinus spp.) trees in North America since its discovery in Michigan in 2002. We evaluated attraction of adult A. planipennis to artificial traps incorporating visual (e.g., height, color, silhouette) and olfactory cues (e.g., host volatiles) at field sites in Michigan. We developed a double-decker trap consisting of a 3-m-tall polyvinyl pipe with two purple prisms attached near the top. In 2006, we compared A. planipennis attraction to double-decker traps baited with various combinations of manuka oil (containing sesquiterpenes present in ash bark), a blend of four ash leaf volatiles (leaf blend), and a rough texture to simulate bark. Significantly more A. planipennis were captured per trap when traps without the rough texture were baited with the leaf blend and manuka oil lures than on traps with texture and manuka oil but no leaf blend. In 2007, we also tested single prism traps set 1.5 m above ground and tower traps, similar to double-decker traps but 6 m tall. Double-decker traps baited with the leaf blend and manuka oil, with or without the addition of ash leaf and bark extracts, captured significantly more A. planipennis than similarly baited single prism traps, tower traps, or unbaited double-decker traps. A baited double-decker trap captured A. planipennis at a field site that was not previously known to be infested, representing the first detection event using artificial traps and lures. In 2008, we compared purple or green double-decker traps, single prisms suspended 3–5 m above ground in the ash canopy (canopy traps), and large flat purple traps (billboard traps). Significantly more A. planipennis were captured in purple versus green traps, baited traps versus unbaited traps, and double-decker versus canopy traps, whereas billboard traps were intermediate. At sites with very low A. planipennis densities, more A. planipennis were captured on baited double-decker traps than on other traps and a higher percentage of the baited double-decker traps captured beetles than any other trap design. In all 3 yr, peak A. planipennis activity occurred during late June to mid-July, corresponding to 800–1,200 growing degree-days base 10°C (DD₁₀). Nearly all (95%) beetles were captured by the end of July at ≈1400 DD₁₀.

A series of laboratory and field studies were conducted using two lines of navel orangeworm, reared on different stages of new crop and mummy pistachios, Pistacia vera L. This study demonstrated the potential importance of malformed pistachios (pea splits) to the population dynamics of navel orangeworm, because these nuts, which are available as early as two months before mature nuts, supported navel orangeworm development and survival. Overall, the developmental rate on new crop pistachios is fastest on mature nuts, 422.3 ± 123 degree-days (DD, °C), but other factors such as exposure to insecticide residue also sped development, although survival decreased. Development took the longest on unharvested nuts (mummies) dried at 90°C for 24 h, 2,664.7 ± 131.4 DD. In most trials development was variable and two generations could develop at the fastest rate before the slowest individual completed development, which in turn calls into question the concept of discrete generations. Generally, survival was highest on mature pistachios and other stages of new crop nut and lowest on mummies collected in May. Survival was also higher on the new varieties ‘Lost Hills’ and ‘Golden Hills’ (24.7 and 32.0%, respectively) than on the most extensively planted variety ‘Kerman’ (13.3%). In our trials, both the rate of development and survival were dependent on nut stage, age, variety, and quality, indicating that pistachios, like almonds, Prunus dulcis (Mill.) D.A.Webb, are a dynamic rather than a static nutrient source for navel orangeworm.

The sex pheromone of the leafminer Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) was deployed in a Florida citrus (Citrus spp.) grove by using a novel deployment device (IFM-413) containing SPLAT, a flowable formulation of an emulsified wax compound designed to provide slow release of semiochemicals. The device consisted of two disks connected by string. Each disk was loaded with 1 g of SPLAT containing either 0.15% (Z,Z,E)-7,11,13-hexadecatrienal (triene) or 2% (Z,Z)-7,11-hexadecadienal (diene). The devices were deployed using a two-dimensional multivariate design to determine the optimal rate of pheromone per unit area and degree of aggregation of the deployment devices (number of trees treated per unit area). The IFM-413 device proved effective at becoming securely entangled in tree branches. Furthermore, the devices effectively delivered pheromone-loaded SPLAT that resulted in disruption of trap catch of male P. citrella. Response surfaces showed a quadratic response of trap catch disruption to both total amount of pheromone per unit area and the degree of aggregation of the deployed devices (number of treated trees per unit area). The response surfaces for 0.15% triene or 2.0% diene were similar. The diene produced an effect similar to that of the triene at ≈13 times the rate of the triene. The greatest disruption of trap catch occurred when the number of treated trees per unit area was greatest (no aggregation of deployment devices). Manufacturing, packaging, and mechanical deployment of the devices remain to be investigated.

We tested the effects among a purportedly sustainable water-soluble fertilizer, a conventional water-soluble fertilizer, an alternation of these, a controlled-release fertilizer, and a clear water control on the life-history traits of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae; = Bemisia argentifolii Bellows & Perring) biotype B reared on poinsettia (Euphorbia pulcherrima Willdenow ex Klotzch). Free amino acids in petioles were measured to estimate plant nutrient assimilation and phloem nutritional quality for B. tabaci biotype B. The sustainable fertilizer produced plants with the highest concentration of amino acids. In contrast, fecundity of whiteflies was lowest in plants treated with the sustainable fertilizer and the water control. The relationship between total amino acids in phloem and survival was significantly quadratic, with the highest survival at intermediate levels. Fecundity, however, was negatively correlated with total amino acid content of the maternal host plant. Variation in total amino acid concentration in petioles of plants treated within fertilizer treatments makes it difficult to predict whether a particular fertilizer will produce plants with enough amino acids to deleteriously affect both survivorship and fecundity and yet yield a plant of good quality. Despite this limitation, we can conclude that the use of this sustainable fertilizer will not cause increases in whitefly populations relative to plants fertilized with water-soluble and slow-release fertilizers that deliver the same level of nitrogen to the plant.

Operational parameters of traps baited with the pheromones of three mealybug species were optimized in nurseries producing ornamental plants. All pheromone doses (1-320 µg) attracted Pseudococcus longispinus (Targioni Tozzetti) and Pseudococcus viburni (Signoret) males, with the lowest dose (1 µg) attracting the fewest males for both species. Doses of 3.2–100 µg were as attractive to male P. longispinus as the highest dose (320 µg); doses from 10 to 320 µg were equally attractive for P. viburni males. Lures containing 25-µg doses of either pheromone had effective field lifetimes of at least 12 wk. Experiments were performed to test the efficacy of combining multiple pheromones to attract several species of mealybugs simultaneously. Lures loaded with a mixture of the pheromones of P. longispinus, P. viburni, and Planococcus citri (Risso) were as attractive to P. viburni and P. citri as lures with their individual pheromones. Response of P. longispinus to the blend was decreased by 38% compared with its pheromone as a single component. A subsequent trial with two-component blends showed that the pheromone of P. citri was responsible for this modest decrease in P. longispinus response. This should not affect the overall efficacy of using these lures for monitoring the presence of all three mealybug species simultaneously. Pheromone traps were used to detect infestations of P. longispinus throughout the season and to track population cycles. When pheromone-baited traps for P. longispinus were compared with manual sampling, trap counts of male mealybugs were significantly correlated with mealybugs counted on plants in the vicinity of the traps.

No-choice tests were conducted to determine whether fruit of southern highbush blueberry, Vaccinium corymbosum L., hybrids are hosts for three invasive tephritid fruit flies in Hawaii. Fruit of various blueberry cultivars was exposed to gravid female flies of Bactrocera dorsalis Hendel (oriental fruit fly), Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), or Bactrocera Cucurbitae Coquillet (melon fly) in screen cages outdoors for 6 h and then held on sand in the laboratory for 2 wk for pupal development and adult emergence. Each of the 15 blueberry cultivars tested were infested by oriental fruit fly and Mediterranean fruit fly, confirming that these fruit flies will oviposit on blueberry fruit and that blueberry is a suitable host for fly development. However, there was significant cultivar variation in susceptibility to fruit fly infestation. For oriental fruit fly, ‘Sapphire’ fruit produced an average of 1.42 puparia per g, twice as high as that of the next most susceptible cultivar ‘Emerald’ (0.70 puparia per g). ‘Legacy’, ‘Biloxi’, and ‘Spring High’ were least susceptible to infestation, producing only 0.20–0.25 oriental fruit fly puparia per g of fruit. For Mediterranean fruit fly, ‘Blue Crisp’ produced 0.50 puparia per g of fruit, whereas ‘Sharpblue’ produced only 0.03 puparia per g of fruit. Blueberry was a marginal host for melon fly. This information will aid in development of pest management recommendations for blueberry cultivars as planting of low-chill cultivars expands to areas with subtropical and tropical fruit flies. Planting of fruit fly resistant cultivars may result in lower infestation levels and less crop loss.

Ohelo (Vaccicinium reticulatum Small) (Ericaceae) is a native Hawaiian plant that has commercial potential in Hawaii as a nursery crop to be transplanted for berry production or for sale as a potted ornamental. No-choice infestation studies were conducted to determine whether ohelo fruit are hosts for four invasive tephritid fruit fly species. Ohelo berries were exposed to gravid female flies of Bactrocera dorsalis Hendel (oriental fruit fly), Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), Bactrocera cucurbitae Coquillet (melon fly), or Bactrocera latifrons (Hendel) in screen cages outdoors for 24 h and then held on sand in the laboratory for 2 wk for pupal development and adult emergence. Only B. dorsalis successfully attacked and developed in ohelo berries. In total, 1,570 berries produced 10 puparia, all of which emerged as adults, for a fruit infestation rate of 0.0064% and an average of 0.0053 puparia per gram of fruit. By comparison, papaya fruit used as controls produced an average of 1.44 B. dorsalis puparia per g of fruit. Ohelo berry is a marginal host for B. dorsalis and apparently a nonhost for C. capitata, B. cucurbitae, and B. latifrons. Commercial plantings of ohelo will rarely be attacked by fruit flies in Hawaii.

Field-based trapping experiments were conducted in Ohio in 2003, 2004, and 2008 to determine the influence of (—)-α-pinene on the attraction of exotic and native ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) to ethanol-baited traps. In 2003 and 2004, we determined the effect of adding an (—)-α-pinene ultrahigh release lure (UHR; 2 g/d at 20°C) to traps baited with an ethanol UHR lure (0.39 g/d). Fewer Anisandrus (Xyleborus) sayi (Hopkins) and Xyleborinus saxeseni (Ratzeburg) were collected in 2003 and 2004 from traps baited with ethanol UHR plus (—)-α-pinene UHR compared with ethanol UHR. (—)-α-Pinene also reduced the attraction of Xyloterinus politus (Say) to ethanol-baited traps in 2004. Total captures of Xylosandrus germanus (Blandford) in 2003 were higher in traps baited with ethanol UHR plus (—) -α-pinene UHR than in traps with ethanol UHR alone but not in 2004. In 2008, captures were compared among traps baited with eight combinations of ethanol and (—)-α-pinene at both UHR and low release (LR) rates. Release rates for ethanol LR and (—)-α-pinene LR were 0.027 and 0.0015g/d, respectively. (—)-α-Pinene UHR and (—)-α-pinene LR reduced the attractiveness of ethanol UHR to A. sayi and X. saxeseni. Ethanol UHR was also more attractive than ethanol LR to A. sayi and X. germanus. These findings demonstrate traps baited with ethanol alone are more effective than ethanol plus (—) -α-pinene for monitoring ambrosia beetle flight activity in ornamental nurseries. Ethanol release rate is also an important consideration for monitoring purposes.

The moth Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) is a key pest of table and wine grape (Vitis spp.) varieties in Cyprus. Many different insecticide combinations were applied for three consecutive years (2006–2008) in a Sultana seedless table grape vineyard, aimed at controlling the first and second generations of this pest under warm and dry Mediterranean climatic conditions. In Cyprus, Sultana is the main early maturing table grape variety grown in the country. L. botrana has two generations and a partial third on this export variety, of which the first two generations are the most destructive. Applications were made according to pheromone trap captures of males. One application was used against the first and two applications against the second generation of L. botrana. A high rate of bunch damage was observed in the untreated rows during all years, reaching 56.7, 62.5, and 69.2% in 2006, 2007, and 2008, respectively. Differences between insecticide treatments and the untreated control were statistically significant. The treatment combination of lufenuron, spinosad, and indoxacarb as well as the combination of chlorpyrifos, spinosa and indoxacarb, used against the first and second generations of L. botrana, were the most effective compared with the untreated control. Satisfactory control of the pest also was observed with other combinations such as lufenuron, cypermethrin, and Bacillus thuringiensis; chlorpyrifos, Cypermethrin, and B. thuringiensis; and lufenuron, deltamethrin, and azadirachtin.

The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera:Triozidae), is a serious pest of potatoes (Solanum tuberosum L.) that can cause yield loss by direct feeding on crop plants and by vectoring a bacterial pathogen, Candidatus Liberibacer psyllaurous. Current pest management practices rely on the use of insecticides to control the potato psyllid to lower disease incidences and increase yields. Although many studies have focused on the mortality that insecticides can cause on potato psyllid populations, little is known regarding the behavioral responses of the potato psyllid to insecticides or whether insecticides can decrease pathogen transmission. Thus, the objectives of this study were to determine the effects of insecticides on adult potato psyllid behaviors, the residual effects of insecticides on potato psyllid behaviors over time, and effects of these insecticides on Ca. L. psyllaurous transmission. Insecticides tested included imidacloprid, kaolin particle film, horticultural spray oil, abamectin, and pymetrozine. All insecticides significantly reduced probing durations and increased the amount of time adult psyllids spent off the leaflets, suggesting that these chemicals may be deterrents to feeding as well as repellents. Nonfeeding behaviors such as tasting, resting, and cleaning showed variable relationships with the different insecticide treatments over time. The insecticides imidacloprid and abamectin significantly lowered transmission of Ca. L. psyllaurous compared with untreated controls. The implications of our results for the selection of insecticides useful for an integrated pest management program for potato psyllid control are discussed.

The aim of the current study was to evaluate the fumigant activity of the essential oils from 11 species of the genus Eucalyptus and two of their hybrids on first instar of Blattella germanica L. The fumigant activity and repellence of the four major monoterpene components of these essential oils also were tested. Fumigant activity was evaluated by exposing nymphs to the vapors emitted by 50 µl of essential oil or monoterpene in a closed container. The lowest knockdown time 50% (KT₅₀) values, expressed in minutes, were elicited by the essential oils of the Eucalyptus grandis × Eucalyptus tereticornis (57.9) hybrid, Eucalyptus sideroxylon A. Cunn (62.0), E. grandis × Eucalyptus camaldulensis (63.8) hybrid, Eucalyptus viminalis Labill (64.1), Eucalyptus dunnii Maiden (64.5), and Eucalyptus grandis (Hill) ex Maiden (68.7). The KT₅₀ values for the remaining essential oils ranged between 74.5 (E. saligna Smith) and 161.4 min (E. tereticornis Smith). The essential oil from the hybrid E. grandis × E. tereticornis was 3.7 times less toxic than dichlorvos (positive control). The KT₅₀ values of monoterpenes were 38.8 for α-pinene, 55.3 for 1,8-cineole, 175.6 for p-cymene, and 178.3 for γ-terpinene. α-Pinene was 2.5 times less toxic than dichlorvos. There was a strong positive correlation between the fumigant activity of essential oils and their corresponding 1, 8-cineole and α-pinene concentration. Repellency was quantified using a video tracking system. Two concentrations of monoterpenes were studied (7 and 70 µg/cm²). All compounds produced a light repellent effect but only when applied at 70 µg/cm². In all cases, the repellent effect was less than that produced by the broad-spectrum insect repellent N,N-diethyl-3-methylbenzamide (positive control).

The spider Holocnemus pluchei (Scopoli) (Araneae: Pholcidae) is a nonnative species commonly found in the southwestern United States. In urban areas around homes and other structures, it is often the dominant spider species on outside surfaces; requests for control of spiders and their cobwebs are common for the commercial pest management industry. We tested two physical (brushing and vacuuming) and two low-impact chemical (permethrin and botanical insecticide) spray control methods for H. pluchei on outbuildings on the University of California-Riverside campus. Forty sites containing at least two H. pluchei spiders along a 5-m section of eave or overhang were chosen for treatment. Treatment was applied within 2 d of a pretreatment census. The number of spiders per section was counted at 2, 4, 8, 12, 16, and 52 wk posttreatment. Untreated sections showed an increase in spiders through summer and a decrease in autumn. Sites treated with permethrin significantly reduced spiders >95% and had strong residual effect throughout the remainder of the sampling period. Compared with untreated controls, the three other treatments did not significantly reduce spiders; these three were similar throughout the season and were intermediate between untreated and permethrin-treated sites. In comparison with the before and 2-wk posttreatments, spiders at the untreated sites showed no difference in body sizes, whereas those in the nonpermethrin treatments showed a decrease, indicating that larger spiders were eliminated. We also tested H. pluchei spiders in the laboratory against the two insecticides used in the field studies to determine the minimum lethal concentrations for controlling H. pluchei.

The efficacy of Xterm, which contains 1% bistrifluron, in the form of cellulose bait pellets was evaluated for its efficacy in eradicating field colonies of the mound-building termite Globitermes sulphureus (Haviland) (Isoptera: Termitidae). The termite mounds were dissected at the end of the experiment to determine whether the colonies were eliminated. By ≈2 mo postbaiting, the body of termite workers appeared marble white, and mites were present on the body. The soldier—worker ratio increased drastically in the colonies, and the wall surface of the mounds started to erode. Colony elimination required at least a 4-mo baiting period. Mound dissection revealed wet carton materials (food store) that were greatly consumed and overgrown by fast-growing fungi. Decaying cadavers were scattered all over the nests. On average, 84.1 ± 16.4 g of bait matrix (68.9 ± 13.4%, an equivalent of 841 ± 164 mg of bistrifluron) was consumed in each colony. Moreover, we found that a mere 143 mg of bistrifluron was sufficient to eliminate a colony of G. sulphureus.

This study was designed to understand the effects of the interspecific competition between red imported fire ant, Solenopsis invicta Buren and two native ant species, Pheidole fervens Smith and Monomorium chinense Santschi, by conducting colony interference and individual confrontation tests under laboratory conditions. The colony interference test showed that both native ant species, owing to their numerical advantage, killed the Solenopsis invicta virus-1 (SINV-1)-infected or healthy queens of S. invicta. Significantly less time was required for M. chinense to kill all SINV-1-infected S. invicta compared with the time required to kill the healthy S. invicta. Compared with healthy S. invicta, SINV-1-infected S. invicta spent a longer time eliminating the P. fervens colonies. In confrontation tests, M. chinense killed a significantly higher number of infected S. invicta minors than they did healthy minors, but the number of S. invicta majors (either infected or healthy) killed was substantially less. This study found that the viral infection weakened the competitive ability of S. invicta and made them prone to be eliminated by M. chinense but not by P. fervens.

The caste composition and sex ratio in a mature and an incipient colony of Cryptotermes dudleyi Banks (Isoptera: Kalotermitidae) was studied. Biometric descriptors of both immature and sexual castes were developed. Morphometric analysis revealed that there are four larval instars, a pseudergate, and three nymphal instars in the development of C. dudleyi. To differentiate between the fourth larval instars and the pseudergate, pronotal width and tibial length must be taken into account, because the head width overlaps between the two groups. The number of antennal segments increases in parallel with instar development. The mature colony was headed by a pair of physogastric nymphoid neotenics; the colony also contained multiple pairs of nonphysogastric de-alates and wing-torn alates. The majority of eggs and larvae were confined to galleries that connected to locations where nymphoid neotenics were found, whereas in general only pseudergates and nymphs were found together with de-alates and wing-torn alates. In contrast, the incipient colony contained only a pair of primary reproductives. Nymphs formed a major group in both mature and incipient colonies, as did pseudergates. The sex ratio of the mature colony was slightly but significantly biased in favor of females, whereas it was skewed toward males in the incipient colony. The data also suggested that the soldier caste was female skewed.

The susceptibility of six Australian broiler house populations and an insecticide susceptible population of lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), to cyfluthrin, β-cyfluthrin, γ-cyhalothrin, and deltamethrin was investigated. One broiler house population had equivalent susceptibility to the susceptible to β-cyfluthrin and γ-cyhalothrin, with higher susceptibility to cyfluthrin and deltamethrin. The remaining five populations demonstrated strong resistance to cyfluthrin (19–37-fold), the insecticide used most widely for management of A. diaperinus in Australia. Each cyfluthrin-resistant population demonstrated reduced susceptibility to β-cyfluthrin (resistance ratios were 8–17-fold), deltamethrin (2.5–8-fold), and γ-cyhalothrin (6–12-fold) compared with the laboratory population, but cross-resistance patterns varied considerably between populations. Adding piperonyl butoxide (PBO) had no effect on the susceptibility of the susceptible population to any of the insecticides, but it increased the susceptibility of each of the five cyfluthrin-resistant populations: to cyfluthrin (synergism ratio range, 1.9–5.0-fold), β-cyfluthrin (1.6– 4.1-fold), and γ-cyhalothrin (1.7–2.0-fold). PBO had a more variable effect on susceptibility to deltamethrin, with three of the cyfluthrin-resistant populations being more susceptible to deltamethrin in the presence of PBO, but susceptibility of the remaining two populations was unaffected by adding PBO (synergism ratio range, 0.9–2.5-fold). Overall, the addition of PBO to the four pyrethroids had variable effects on their susceptibility. This variability indicated the presence of other resistance mechanisms in beetle populations apart from metabolic resistance. In addition, the relative importance of metabolic resistance in each beetle population varied widely between pyrethroids. Thus, it cannot be assumed that PBO will reliably synergize pyrethroids against cyfluthrin-resistant lesser mealworm populations when using it to mitigate insecticide resistance.

In southern Brazilian apple (Malus spp.) orchards, predominantly organophosphates are used to control the oriental fruit moth, Cydia molesta (Busck) (Lepidoptera: Tortricidae), but control failures often occur. Therefore the susceptibility of three C. molesta Brazilian populations was investigated to five insecticides of different groups and modes of action, in comparison with a susceptible laboratory strain mass reared in southern France for >10 yr. At the same time, comparative biochemical and genetic analysis were performed, assessing the activities of the detoxification enzymatic systems and sequencing a gene of insecticide molecular target to find out markers associated with resistance. The three Brazilian populations were significantly resistant to chlorpyrifos ethyl compared with the reference strain. One of the field populations that had been frequently exposed to deltamethrin treatments showed significant decreasing susceptibility to this compound, whereas none of the three populations had loss of susceptibility to tebufenozide and thiacloprid compared with the reference strain. All three populations had slight but significant increases of glutathione transferase and carboxylesterases activities and significant decrease of specific acetylcholinesterase activities compared with the reference. Only the most resistant population to chlorpyriphos exhibited a significantly higher mixed function oxidase activity than the reference. The acetylcholinesterase of females was significantly less inhibited by carbaryl in the Brazilian populations than in the reference strain (1.7–2.5-fold), and this difference was not expressed in the male moth. However, no mutation in the MACE locus was detected. These biological and molecular characterizations of adaptive response to insecticides in C. molesta provide tools for early detection of insecticide resistance in field populations of this pest.

The planthopper Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) is a serious insect pest of rice, Oryza sativa L., and has developed resistance to fipronil in Japan. Sequence analysis of L. striatellus RDL γ-aminobutyric acid (GABA) receptor subunit (LS-RDL) genes from a fipronilresistant population and a fipronil-susceptible strain identified the A2′N mutation (index number for M2 membrane-spanning region), that was previously implicated in fipronil resistance in the planthopper Sogatella furcifera (Horváth) (Hemiptera: Delphacidae). Nineteen of 21 fipronil-resistant L. striatellus individuals were genotyped as heterozygous for the A2′N mutation, suggesting that this mutation is associated with fipronil resistance and that most fipronil-resistant L. striatellus express wild-type and A2′N mutant LS-RDL simultaneously. To confirm the role of the A2′N mutation of LS-RDL, Drosophila Mel-2 cells were transfected with wild-type and A2′N mutant LS-RDL genes, either individually or together. A membrane potential assay showed that fipronil had no inhibitory effect at 10 μM on cells transfected with the A2′N mutant LS-RDL gene with or without the wild-type LS-RDL gene. By contrast, the IC₅₀ value of fipronil for wild-type LS-RDL homomers was 14 nM. These results suggest that the A2′N mutation of the RDL GABA receptor subunit confers fipronil resistance in L. striatellus as well as S. furcifera.

Insecticide control is the major measure for suppression of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae) damage, and a few insecticides used for long time have proved to fail to control this pest in China. Several new chemicals have been introduced for control of C. medinalis. However, there was no baseline susceptibility data of C. medinalis to insecticides used or will be in use. In this study, a seedling dipping method was developed for bioassay of insecticide susceptibility of C. medinalis. Dose responses of C. medinalis to 11 insecticides were tested. Interpopulation sensitivity to insecticides was compared. Based on LC₅₀ values, C. medinalis was most susceptible to antibiotic insecticides (abamectin, emamectin benzoate, and spinosad) and least sensitive to monosultap and a Bacillus thuringiensis (Bt) product. Chlorantraniliprole and insect growth regulator (IGR) insecticides (tebufenozide and hexaflumuron) exhibited great efficacy against C. medinalis. No susceptibility difference was observed for antibiotic insecticide and IGR insecticides among three populations. Narrow variation in tolerant level was detected for organo-phosphates insecticides, chlorantraniliprole, monosultap, and Bt. The results in this study provided baseline susceptibility data of C. medinalis to 11 insecticides and also offered useful information for choice of alternative insecticide and for integrated resistance management of C. medinalis.

We evaluated the ability of dual applications of natural, plant-derived acaricides to suppress nymphal Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) in a Lyme disease endemic area of New Jersey. An aqueous formulation of 2% nootkatone provided >90% control of I. scapularis through 7 d. Control declined to 80.9% at 14 d, and a second application was made that provided >95% control through the remaining 4 wk of the nymphal season. Nootkatone provided >90% control of A. americanum through 35 d postapplication. Applications of 2% carvacrol and EcoTrol T&O resulted in rapid knockdown of both tick species, but control declined significantly to 76.7 and 73.7%, respectively, after 14 d when a second application was made that extended control of both tick species to between 86.2 and 94.8% at 21 d. Subsequently, control declined steadily in all plots by 42 d postapplication except for I. scapularis in carvacrol-treated plots, where levels of control >90% were observed through 35 d. Of the three compounds tested, 2% nootkatone provided the most consistent results, with 96.5 and 91.9% control of I. scapularis and A. americanum through 42 and 35 d, respectively. The ability of plant-derived natural products to quickly suppress and maintain significant control of populations of these medically important ticks may represent a future alternative to the use of conventional synthetic acaricides. In addition, the demonstrated efficacy of properly-timed backpack sprayer application may enable homeowner access to these minimal-risk acaricides.

Endophytic fungi belonging to the genus Neotyphodium, confer resistance to infected host grasses against insect pests. The effect of host species, and endophtye species and strain, on feeding and survival of the corn flea beetle, Chaetocnema pulicaria Melsheimer (Coleoptera: Chrysomelidae) was investigated. The grass—endophyte associations included natural and artificially derived associations producing varying arrays of common endophyte-related alkaloids or alkaloid groups, peramine, lolitrem B, ergovaline, and the lolines. Preference and nonpreference tests showed that C. pulicaria feeding and survival were reduced by infection of tall fescue with the wild-type strain of N. coenophialum, the likely mechanism being antixenosis rather than antibiosis. In the preference tests, endophyte and host species effects were observed. Of the 10 different Neotyphodium strains tested in artificially derived tall fescue associations, eight strongly deterred feeding by C. pulicaria, whereas the remaining two strains had little or no effect on feeding. Infection of tall fescue with another fungal symbiont, p-endophyte, had no effect. Perennial ryegrass, Lolium perenne L., infected with six strains of endophyte, was moderately resistant to C. pulicaria compared with endophyte-free grass, but four additional strains were relatively inactive. Six Neotyphodium—mendow fescue, Festuca pratensis Huds., associations, including the wild-type N. uncinatum—mendow fescue combination, were resistant, whereas three associations were not effective. Loline alkaloids seemed to play a role in antixenosis to C. pulicaria. Effects not attributable to the lolines or any other of the alkaloids examined also were observed. This phenomenon also has been reported in tests with other insects, and indicates the presence of additional insect-active factors.

Transgenic cotton (Gossypium hirsutum L.) varieties, adapted to China, have been bred that express two genes for resistance to insects. the Cry1Ac gene from Bacillus thuringiensis (Berliner) (Bt), and a trypsin inhibitor gene from cowpea (CpTI). Effectiveness of the double gene modification in conferring resistance to cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), was studied in laboratory and field experiments. In each experiment, performance of Bt CpTI cotton was compared with Bt cotton and to a conventional nontransgenic variety. Larval survival was lower on both types of transgenic variety, compared with the conventional cotton. Survival of first-, second-, and third-stage larvae was lower on Bt CpTI cotton than on Bt cotton. Plant structures differed in level of resistance, and these differences were similar on Bt and Bt CpTI cotton. Likewise, seasonal trends in level of resistance in different plant structures were similar in Bt and Bt CpTI cotton. Both types of transgenic cotton interfered with development of sixth-stage larvae to adults, and no offspring was produced by H. armigera that fed on Bt or Bt CpTI cotton from the sixth stage onward. First-, second-, and third-stage larvae spent significantly less time feeding on transgenic cotton than on conventional cotton, and the reduction in feeding time was significantly greater on Bt CpTI cotton than on Bt cotton. Food conversion efficiency was lower on transgenic varieties than on conventional cotton, but there was no significant difference between Bt and Bt CpTI cotton. In 3-yr field experimentation, bollworm densities were greatly suppressed on transgenic as compared with conventional cotton, but no significant differences between Bt and Bt CpTI cotton were found. Overall, the results from laboratory work indicate that introduction of the CpTI gene in Bt cotton raises some components of resistance in cotton against H. armigera, but enhanced control of H. armigera under field conditions, due to expression of the CpTI gene, was not demonstrated.

The sweep net is a standard sampling method for adults of the western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae), in cotton (Gossypium spp.). However, factors that influence the relationship between true population levels and population estimates obtained using the sweep net are poorly documented. Improved understanding of these factors is needed for the development and application of refined treatment thresholds. Recent reports of significant among-sampler differences in sweep net-based population estimates of the adult tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), seem to preclude meaningful comparisons of population estimates collected by different samplers. We used a mark—release—recapture method and the standard sweep net to evaluate among-sampler differences in population estimates of L. hesperus adults. Adult lygus, marked with fingernail polish to facilitate identification and prevent flight, were released into 10-m sample rows on the evening before 10-sweep samples were collected the following morning. The experimental design was a randomized complete block with three replications of three treatments (sampler). Separate experiments were conducted in two plantings each of Pima (Gossypium barbadense L.) and Acala (Gossypium hirsutum L.) cotton. Collections of marked bugs from each study were evaluated for effects of sampler, sample date, and their interaction. Although differences in lygus collections were observed among sample dates in some tests, no differences were detected in the population estimates by different samplers. These results demonstrate that the sweep net technique can be sufficiently standardized to allow direct comparison of population estimates obtained by different samplers.

Biological control of rice weevil, Sitophilus oryzae (L.), and Indianmeal moth, Plodia interpunctella (Hübner), by their parasitoids Anisopteromalus calandrae (Howard) and Bracon hebetor Say was examined while considering the intraspecific competition pattern of the pests. In both experimental and simulation studies, A. calandrae was shown to suppress the rice weevil population, a contest type competitor, regardless of the parasitoid/weevil ratios tested. In contrast, B. hebetor only significantly suppressed the Indianmeal moth, a scramble type competitor, when the parasitoid/moth ratio was >0.05. At ratios lower than 0.05, the role of B. hebetor was negligible, and the correlation coefficients between the number of moths that had emerged and the parasitoid/moth ratio was estimated to be 0.07. The control efficiency of the two parasitoids with respect to the parasitoid/host ratio was estimated using a ratio-response model. To suppress the weevil density to a level that was only 10% of the current density, the ratio was estimated to be 0.02, whereas this value was 0.14 for the Indianmeal moth. However, for the continuous suppression of the Indianmeal moth, periodic and iterative introduction of B. hebetor was required.

A web-based model was used to simulate the impact of aeration on population growth of the lesser grain borer, Rhyzopertha dominica (F.), and the rice weevil, Sitophilus oryzae (L.), in stored rough rice, Oryza sativa L., at Beaumont, TX. Simulations were run for each of 10 yr with 1 August as the start date; 31 December as the end date; beginning populations of 2.5 adults per metric ton (1,000 kg); starting grain temperatures of 29.4, 32.2, and 35.0°C; and aeration airflow rates of 0.27, 0.79, and 1.40 m³/min/metric ton of rice. In the absence of aeration, populations of both species increased exponentially, with maximum production of R. dominica and S. oryzae at starting grain temperatures of 35.0 and 32.2°C, respectively. Final predicted populations of R. dominica on 31 December from grain starting temperatures of 29.4, 32.2, and 35.0°C were 5,465, 6,848, and 11,855 per ton, respectively; final predicted populations of S. oryzae were 13,288, 21,252 and 4,355, respectively. Aeration led to a reduction in grain temperature and a decrease in pest populations, regardless of starting grain temperature or aeration airflow rates. Predicted populations of R. dominica on 31 December ranged from 12 to 63 adults per ton at all grain starting temperatures and airflow rates; populations of S. oryzae on 31 December ranged from 108 to 193 adults per ton at all grain starting temperatures and airflow rates. The predicted population levels in aerated rice represented at least a 98% reduction compared with unaerated rice. Results show the utility of the web-based model and how the various model inputs can help define broader patterns of insect control in rice stored in the south central United States.