Potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae), is a key pest of potato (Solanum tuberosum L.) and other solanaceous crops (Solanales: Solanaceae) as a vector of “Candidatus Liberibacter solanacearum” (Lso), the pathogen associated with zebra chip disease of potato. Potato psyllid populations typically are monitored using sticky card traps, and psyllids collected from sticky traps often are subjected to polymerase chain reaction (PCR) to monitor the incidence of Lso within psyllid populations. Psyllids collected from sticky traps are often mangled, desiccated, and coated with sticky residue, which may interfere with detection of Lso by PCR. A recently developed prototype 3-dimensional-printed trap that captures insects directly into a preservative (70% ethanol) was previously tested for monitoring psyllid populations. The capture of psyllids directly into a preservative may reduce degradation of DNA or protect specimens from PCR-inhibiting contaminants, thus improving the detection of Lso by PCR. Our goal was to compare the detectability of Lso in psyllids captured into preservative (prototype trap) to that in psyllids removed from sticky card traps. Overall, detection rates were higher in psyllids from the prototype trap than from sticky card traps. This improvement in Lso detection appeared to be partly due to the specimens yielding more DNA of higher quality. Results of this study demonstrate that compared with sticky card traps, a trap that captures psyllids directly into a preservative provides higher quality specimens for collection of molecular data, including pathogen diagnosis, population genetics, and molecular gut content analysis.

We sampled mosquito larvae and adult females in east-central Georgia (Screven County), where two species of mosquitoes, Coquillettidia perturbans (Walker) and Culiseta melanura (Coquillett), believed to be important in the epidemiology of eastern equine encephalitis virus (EEEv) were common. The study site, being a wildlife management area, supported large numbers of birds and snakes that are believed to harbor EEEv, and EEEv had been historically reported from wild birds from Screven County. Thus, the location was conducive to studying aspects of the sylvatic cycle of EEEv. Adult traps (CO₂ baited) indicated that Cs. melanura adult females were only common in midsummer. In contrast, Cq. perturbans adult females were common for almost the entire summer, and this combined with larval sampling in local wetlands suggested that Cq. perturbans was bivoltine in east-central Georgia, which is much farther north than previously suspected. We did not detect EEEv in any mosquito samples, but the phenology of Cq. perturbans suggests that only the second generation of these mosquitoes would play an important role as bridge vectors of EEEv to humans and horses in eastern Georgia.

Bemisia tabaci (Gennaduis) is a large complex of cryptic species whose members are invasive pests of economically important commodities, including cotton, vegetables, and ornamental crops. A new state detection of Mediterranean (MED; biotype Q) whitefly on poinsettia from a commercial greenhouse was made in Wisconsin in July 2018, bringing the total positive MED whitefly states to 27, indicating that MED is still expanding its geographical range in the United States. Middle Eastern Asia Minor 1 (MEAM1; biotype B) and MED whiteflies were the primary targets for this survey of agricultural ecosystems from field, greenhouse, and nursery plants. Seventy samples were collected from 19 crops across 23 counties in Georgia, with the bulk of the samples taken in 2016 and 2017. Five whitefly samples were collected in both 2011 and 2012, representing nine counties and five different host plants (verbena, lantana, pepper, cucumber, and poinsettia). Overall, cotton was the most heavily sampled commodity (n = 27), followed by 7 samples of bell or ornamental pepper and 6 samples each of poinsettia, peanut, and squash. Other crops sampled included soybean, cowpea, corn, snap bean, zucchini, kale, tomato, sweet potato, eggplant, cantaloupe, and mum. MED whitefly of the B. tabaci cryptic species complex was detected on verbena and lantana in 2011 and poinsettia in 2012 at commercial greenhouses. Only MEAM1 whitefly was detected in all the field grown commodities sampled in Georgia regardless of the year. This survey serves as a baseline for Georgia in the event that MED whiteflies are eventually detected in the field.

The trunks of southeastern pines provide vital habitat for many invertebrates that are, in turn, available as prey for bark-foraging birds. Knowing how these arthropods are distributed vertically on tree trunks is important and may allow for a rapid assessment of prey response to forest management practices. In this study, we used a fast-acting insecticide to sample the arthropods on the lower (0–3 m) and upper (3–9 m) bole sections of nine loblolly pine, Pinus taeda L., trees. We collected over 1,600 arthropods representing 15 orders and 66 families. Ants (Hymenoptera: Formicidae) were the most abundant group collected, and wood cockroaches (Blattodea: Blattellidae) accounted for the greatest overall biomass. Abundance and biomass of arthropods per m² were greater on the lower trunk, but these values were strongly correlated with those from the upper trunk. Nonmetric multidimensional scaling and permutational multivariate analysis of variance showed that arthropod community composition differed significantly between the two trunk positions. Additionally, indicator species analysis found four flightless taxa to be significantly associated with the lower trunk (Araneae, Zygentoma, Hymenoptera, and Pseudoscorpiones) but none with the higher trunk position. These findings show that bark-dwelling arthropods are generally more abundant near the bases of trees and that there is a strong relationship between abundance and biomass between lower and upper trunk sections. Knockdown insecticides offer an effective tool for rapidly assessing the availability of invertebrate prey for bark-foraging birds.

Natural phenolics and reactive oxygen chemical species can have metabolic and fitness costs in insects and thus represent potential insecticidal agents. The response levels of total protein, phenoloxidase, proteases, chitinases, and total antioxidant activities to dopamine and hydrogen peroxide (H₂O₂) injected into third-instar flesh fly, Sarcophaga surcoufi Villeneuve (Diptera: Sarcophagidae), larvae were measured. In comparison to control groups, total protein initially increased following treatment with H₂O₂, but decreased at later sampling intervals. Treatment with dopamine did not affect total protein or protease activity for up to 12 h after treatment, but a slight decrease was observed in both at 24 and 36 h after treatment. Treatment with H₂O₂ decreased protease activity at all sampling intervals. H₂O₂ treatment increased phenoloxidase activity at each sampling interval, while treatment with dopamine decreased the activity at each interval. Total antioxidant activity increased substantially 12 h after treatment with H₂O₂ and increased only slightly 24 h after treatment before decreasing at 36 h, while dopamine increased antioxidant activity at all sampling intervals. Chitinase activity increased 12 h after H₂O₂ treatment, but then decreased at 24 and 36 h, but dopamine had no effect on chitinase activity. Antioxidants, phenoloxidase, and chitinase are important metabolic defense components in insects, and increases or decreases in each impacts the physiological integrity of the insect exposed to stressors that increase or decrease their quantity and activity.

Body color dimorphism is a common phenomenon in a wide range of insect taxa. In Gampsocleis sedakovii obscura (Walker), the two morphs are green and brown. In order to explore the variation within the same species with different body color phenotypes, morphology, genetics, and male calling songs were compared within Gampsocleis from Inner Mongolia, China. Recordings of the male calling songs were compared based on the acoustic variables including pulse duration, pulse interval, dominant frequency, highest frequency, and lowest frequency. This analysis was combined with sequencing of mitochondrial DNA cytochrome c oxidase subunit I and cytochrome c oxidase subunit II and examination of morphological traits to perform cluster analyses. The morphological and the mitochondrial genetic analyses revealed no differences between green and brown morphs, but the acoustic analysis showed completely different male calling between the morphs, thus suggesting that there is a connection between acoustic signals and body color dimorphism in G. s. obscura. These findings also revealed that the acoustic variation with body color dimorphism could provide evidence for insect acoustic signal divergence and the process of subspeciation, even speciation.

Broad-spectrum insecticides are the standard control method used in tree fruit orchards to control periodical cicadas (Magicicada spp.) and to reduce associated oviposition injury to woody host plant tissue. The purpose of this study was to evaluate the effectiveness of two organically approved methods; foliar applications of Organic Materials Review Institute (OMRI)-registered insecticides; and physical exclusion to manage periodical cicada oviposition injury in a commercial apple orchard. Insecticides evaluated included kaolin clay and neem + karanja oil (mixed in a 1:1 ratio). The physical exclusion method involved covering trees with polypropylene fabric. Oviposition injury assessed during the study included the number of periodical cicada eggnests, eggnests per scar, and flagged branches. Neither kaolin clay nor neem + karanja oil significantly reduced periodical cicada oviposition injury compared with the untreated control. Trees covered with exclusion fabric sustained no injury from periodical cicadas. Despite the injury sustained by insecticide-treated and control trees, the extent of periodical cicada oviposition with several tree growth characteristics (tree height, tree canopy width, and trunk circumference) was not significantly correlated.

Dalotia coriaria Kraatz (Coleoptera: Staphylinidae) is a commercially available, soil-dwelling predator that preys upon a variety of insect pests that reside in soils or growing media. The impact of D. coriaria on the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), however, is not well documented. Three laboratory experiments were conducted to assess predation efficacy of D. coriaria adults on western flower thrips pupal populations typically found in the soil or growing medium. Treatments included prepupae only, pupae only, and a prepupae-pupae combination (1:1). Six numbers (0, 1, 2, 3, 4, and 5) of beetle adults and four initial numbers (15, 20, 25, and 30) of thrips pupal populations were examined for each pupal stage treatment. For each pupal stage treatment, the estimated mean probability of thrips adults captured on yellow sticky cards decreased as the number of beetle adults released increased from one to three, but there was no significant effect after releasing additional beetles. Furthermore, there were no differences in response to the predator:prey ratio or initial prey number within each predator:prey ratio examined across the pupal populations examined in this study. These results (a) provide insight into the predatory behavior of D. coriaria adults on western flower thrips pupal populations, which may have practical implications for greenhouse production systems; and (b) indicate that, regardless of the initial numbers of western flower thrips prepupae and/or pupae in the growing medium, three D. coriaria adults per 15.2-cm container may be recommended for use of this predator against western flower thrips.

Butterflies (Lepidoptera) can absorb heat from sunlight to increase their thoracic temperature above the threshold for flight. Autonomous flight is closely related to the reproductive success of butterflies; however, it is unclear whether light intensity controls the ability of butterflies to absorb heat and alter flight activity and, thus, affect reproduction. Such insight would provide an improved understanding of the utilization of solar heat by insects. In this study, we investigated the flight behavior of Danaus chrysippus (L.) (Lepidoptera: Danaidae) in the field and measured the thoracic temperature of butterflies when flying and perching. We determined the effects of thoracic temperature on flight frequency and reproductive success under a light intensity range of 2,000–45,000 luminous flux per unit area (lx). Within this range, strong sunlight significantly increased the flight activity of butterflies in the field. Adults absorbed heat from sunlight to maintain a thoracic temperature that was 4–4.5°C higher than the ambient temperature to allow autonomous flight. Light intensity between 15,000 and 45,000 lx enabled butterflies to absorb more heat to reach an equilibrium temperature, increasing the frequency of autonomous flight and mating. In summary, light intensity influences the autonomic flight activity of butterflies and then significantly affects mating frequency and reproduction. Thus, light intensity manipulation can be used to regulate butterfly reproduction for their conservation and utilization in laboratory breeding facilities.

Populations of host-seeking blacklegged tick, Ixodes scapularis (Say) and lone star tick, Amblyomma americanum (L.), nymphs were monitored at selected sites for 4 yr and at additional randomly selected sites in the Greenbelt National Park, MD for two of those years. Ticks collected from the random sites during the second year of the study were tested for the presence of human pathogens. Borrelia burgdorferi Johnson et al. was detected in 22.2% of the I. scapularis nymphs collected while Anaplasma phagocytophilum Foggie (Dumler et al.) was detected in 3.7%, and one nymph was coinfected with both pathogens. No I. scapularis nymphs tested positive for Babesia microti (França) and no A. americanum nymphs tested positive for Ehrlichia spp. In the years when both random and nonrandom sites were sampled (sampled ≤2 d apart, n= 14 d), significantly more A. americanum nymphs (P= 0.003) were captured at the nonrandom sites than at the random sites; no difference (P = 0.2415) was found for I. scapularis nymphs. No density effect due to vegetational communities was found for nymphs of either species of tick. Host-seeking nymphs of both species of ticks were abundant the first year of flag sampling, dropped dramatically in numbers the second year, and gradually increased (particularly A. americanum) the following 2 yr. The annual variations in tick densities demonstrate the value of early season–monitoring of tick populations on park premises, which affords park managers an opportunity to take appropriate measures in the event of a year of high tick abundance.

An essential oil extracted from bay laurel, Laurus nobilis (L.), was chemically characterized and tested against fourth-instar Culiseta longiareolata (Macquart) (Diptera: Culicidae). Percentage composition of the oil in L. nobilis was 0.96, and gas chromatography–mass spectrometry analysis identified 56 components with eucalyptol (25.62%), linalool (11.83%), methyl eugenol (10.07%), and camphene (10.18%) as the major constituents. Laboratory bioassays demonstrated significant larvicidal activity of the oil extract with cumulative median lethal concentrations (i.e., LC₅₀) of 203.7 parts per million (ppm) at Day 1, 171.9 ppm at Day 3, and 85.1 ppm at Day 7 after exposure. The essential oil also affected egg hatch and sex ratio of the progeny. These results suggest that the essential oil extracted from L. nobilis has potential for development as a management tactic directed against Cs. longiareolata.

The inhibition by three essential oils of the growth and esterase production of German cockroaches, Blattella germanica (L.) (Blattodea: Ectobiidae), with and without symbiotic bacteria, was determined in laboratory assays. Essential oils extracted from Lilium brownii var. viridulum Baker, Croton tiglium L., and Lonicera japonica Thunberg were mixed with a powdered rat food at a 10% concentration and fed to cockroach nymphs. Body mass and body length were measured in adults in all three treatments. Acetylcholinesterase and nonspecific esterase activities were compared between the Lilium and Croton essential oil treatments. The nonlethal doses of these essential oils reduced cockroach growth, while the growth of the females lacking symbiotic bacteria was significantly reduced when fed the diet containing Lilium essential oil. Lilium and Croton essential oils significantly inhibited esterase activity. Our results indicate that symbiotic gut bacteria might be involved in mediating detoxification in the German cockroach.