The caddisfly genus Protoptila (Trichoptera: Glossosomatidae: Protoptilinae) has never before been recorded from Bolivia. Protoptila dubitans Mosely 1939 is now reported from Bolivia for the first time. Additionally, two new species from Bolivia, P. diablita and P. julieta are described. Protoptila julieta is most closely related to P. misionensis Flint 1972. Protoptila diablita is the first known species in the genus to possess scale-like setae. These scales are hypothesized to aid in the dispersal of male sex pheromones.

Four genera and seven species of the scarab beetle tribe Bolboceratini s.l. in Taiwan are reviewed, including the description of a new species, Bolbelasmus minutus Li & Masumoto. After a detailed comparison with the holotype, Bolbelasmus kurosawai Masumoto is considered a junior synonym of Bolbelasmus coreanus (Kolbe). Bolbelasmus meridionalis Krikken is now excluded from the fauna of Taiwan. Key (males only), redescriptions, illustrations, the type depository, commentary, phenology, geographical distributions, and drawings of the male genitalia of each valid species are included. Additionally, a key to the genera of the Eurasian Bolboceratini s.l. is provided.

Results of analyses of molecular sequence (COI, 28S-D2) and morphology (21 character states) data, both alone and combined, were used to determine relationships between 18 species of Scirtothrips (Thysanoptera: Thripidae, Thripinae). Two species of Neohydatothrips from Panama were used as the outgroup. Five major pest Scirtothrips were included in these analyses: S. aurantii, S. citri, S. dorsalis, S. kenyensis, and S. perseae. Trees generated from a parsimony analysis of molecular data and Bayesian analysis of molecular and morphology data combined showed high levels of congruence. The morphology-only tree had several differences in species groupings when compared with trees derived using molecular data. Both parsimony and Bayesian analyses using molecular data indicated that Scirtothrips species associated with avocados were monophyletic, a result not observed with morphological analyses. No support was found for a monophyletic S. dorsalis clade when sampled from six different countries. The S. dorsalis complex may be comprised of at least three separable groups identifiable at the molecular level, but indistinguishable morphologically. The implications of this finding for S. dorsalis, a thrips pest of global significance with high invasion potential, are discussed.

The suprageneric classification of the order Entomobryomorpha (families Isotomidae, Tomoceridae, Oncopoduridae, Actaletidae, Coenaletidae, Paronellidae, Entomobryidae, Microfalculidae, Oncobryidae, and Praentomobryidae) is examined and revised. The families are placed in four superfamilies: Isotomoidea; Coenaletoidea, new status; Tomoceroidea; and Entomobryoidea. One new subfamily, Capbryinae, and two new tribes, Nothobryini and Bessionellini, are proposed. Entomobryoidea is examined in more detail at the level of subfamilies and tribes. The characteristics used for this classification are discussed and a scheme is presented. The rationale for the divisions used is discussed.

Taxonomy of the wide-ranging Nearctic velvet ant genus Dilophotopsis Schuster (Hymenoptera: Mutillidae) is reviewed using molecular and morphological comparisons. The validity of the four designated subspecies of Dilophotopsis concolor (Cresson) is examined. Dilophotopsis concolor paron (Cameron) is morphologically and molecularly distinct from the other three subspecies, and it is raised to the species level [D. paron (Cameron), nov. stat.]. Dilophotopsis concolor crassa (Viereck) and Dilophotopsis concolor laredo Schuster are morphologically indistinguishable from the nominative subspecies D. concolor concolor, and they are considered junior synonyms of this species. A key to the species of Dilophotopsis is provided. The distributions of Dilophotopsis species, as well as the genetic variation within D. concolor, are associated with individual arid lands, and they indicate that this genus will be useful in the study of the historical biogeography of the North American arid lands.

Morphological identification of the mealybug species Planococcus citri (Risso) and P. minor (Maskell), two serious agricultural pests, is often complicated by the existence of intermediate forms and a lack of knowledge of the intraspecific variation that occurs in each species. In this study, we have explored the utility of two molecular markers, the mitochondrial gene cytochrome oxidase I (COI) and the nuclear gene, elongation factor 1α (EF-1α) to ascertain the identity of these species and to provide reliable characters for their identification. Results from maximum parsimony analysis of DNA sequence data from both genes indicate the existence of a third clade from the Hawaiian Islands, whose members are distinct from both P. citri and P. minor. The individuals that group in this additional clade, although morphologically identical to P. citri, cluster with P. minor in ≈50% of the cladograms obtained with the COI, and 80% of the cladograms obtained with EF-1α. Our studies show that COI, in combination with morphological and geographical data, can be used to accurately identify the P. minor clade, the P. citri clade, and the clade from the Hawaiian Islands in most cases. Given a few instances in which identification resulting from COI and EF-1α were in conflict, however, our results must be interpreted with caution and until additional studies are performed, no changes are proposed in the taxonomy of this species complex.

Laboratory experiments have shown that larvae of ectoparasitoids Brachinus explodens Duftschmid and Brachinus crepitans (L.) (Coleoptera: Carabidae) develop on pupae of spring breeding species of the genus Amara (Coleoptera: Carabidae). In this study, we investigated the synchronization of the critical stages of host and parasitoid in the field. We simulated the development of both genera under field conditions in spring 2003, combining 1) field data (activity-density measured by pitfall traps and oviposition), 2) thermal constants for development (lower development threshold and sum of effective temperatures), and 3) meteorological data (average daily temperature at a depth of 2.5 cm). In early spring, adults of Amara oviposited in weedy areas, which provided plenty of seed with which to feed their larvae. Pupation was predicted to occur from June to early July. Brachinus adults arrived later than their hosts, and females started to oviposit when Amara larvae were just about to pupate, and Brachinus larvae hatched when Amara pupae became available. The synchronization of the critical stages of host and parasitoid observed in the field strongly supports the existence of a host-parasitoid relationship between Amara pupae and Brachinus larvae.

This work describes the annual and daily activity patterns of two parasitoid fly communities of the fire ant Solenopsis invicta (Hymenoptera: Formicidae) in their native range in Argentina. Pseudacteon (Diptera: Phoridae) flies were censused monthly for 1 yr at two sites in northwestern Corrientes province. Additionally, parasitism rates of S. invicta colonies naturally attacked in the field by Pseudacteon flies are reported for the first time from its native habitat. In total, 4,528 flies (86.3% females) of eight Pseudacteon species were collected attacking ants in the field. Pseudacteon litoralis Borgmeier and Pseudacteon nocens Borgmeier represented 71–79% of female flies censused in both sites. Most species were active throughout the year, although abundances were variable over time and between sites. The highest occurrence peaks of flies were recorded in spring, whereas the lowest occurrence was in summer. Fly abundance was higher close to dusk, whereas species diversity was highest at midday. Relationships among species were established based on their activity patterns and genetic proximity. The presence and abundance of four species were explained by climatic variables, whereas two species may have inherited similar circadian rhythms from a common ancestor. Overall, the parasitism rate by the nine species recorded was very low (0.24%). The highest percentage of parasitized workers was found in spring (0.5%) and occurred within the most complex habitat (gallery forest). The highest parasitism rate per site and colony was also for this habitat in spring (1.16 and 2.81%, respectively). The highest rates of emergence were recorded for Pseudacteon nudicornis Borgmeier.

Functional wing polymorphism is commonly observed in insects, and it may confer an important adaptive value to populations that bear this trait, because it allows dispersal and the location to more favorable habitats for their survival and reproduction. According to the oogenesis-flight syndrome theory, such wing polymorphism may imply differences in the locomotion capacity of individuals, which is a factor induced by adverse environmental conditions during muscle development in immatures. Scaptocoris carvalhoi Becker (Hemiptera: Cydnidae) is an important agriculture pest in Brazil, and it has burrowing habits. The adults swarm in the beginning of the rainy season after a prolonged drought period in the Brazilian cerrado region. In these swarms, part of the population leaves the soil, performing long flights until locations with more abundant vegetation. In this study, we characterized wing polymorphism in S. carvalhoi, this being the first description in a species of Cydnidae. Brachypterous and macropterous males and females were observed, which showed positive and significant correlations between body length and hindwing length. Macropterous individuals demonstrated greater locomotion capacity than brachypterous individuals. In addition, only long-winged adults could fly, showing wing mobility and flight reaction. The increased number of macropterous individuals inside the soil during the swarming season and in the beginning of the rainy period suggests that wing polymorphism in this population occurs in seasonal cycles and that factors related to the scarcity of rains influence the development of immatures and the formation of polymorphic adults.

RESUMO O polimorfismo alar funcional é comumente observado em insetos e pode conferir um valor adaptativo importante para as populações que o apresentam, uma vez que permite a dispersão e localização de habitats mais propícios a sua sobrevivência e reprodução. De acordo com a teoria da oogenesis flight muscle esse polimorfismo alar pode implicar em diferenças na capacidade de locomoção dos indivíduos, fator este resultante da indução por condições ambientais adversas durante o desenvolvimento muscular dos imaturos. Scaptocoris carvalhoi Becker (Hemiptera: Cydnidae) possui hábitos subterrâneos e os adultos realizam a revoada no início da época chuvosa e após um longo período de escassez de chuvas na região do cerrado brasileiro. Nessas revoadas, parte da população deixa o solo, realizando vôos longos até locais com vegetação mais abundante. Neste estudo, caracteriza-se o polimorfismo alar em S. carvalhoi realizando-se a primeira descrição dessa natureza em uma espécie de Cydnidae. Foram observados machos e fêmeas braquípteros e macrópteros, os quais apresentaram correlações positivas e significativas entre o comprimento do corpo e das asas posteriores. Indivíduos macrópteros demonstraram maior capacidade de locomoção do que braquípteros. Além disso, somente adultos de asas longas foram capazes de voar, apresentando mobilidade das asas e reação de vôo. O incremento de macrópteros no interior do solo na época das revoadas e início do período chuvoso sugere que o polimorfismo alar nessa população ocorre em ciclos sazonais e que os fatores relacionados a escassez de chuvas influenciem o desenvolvimento de imaturos e a formação de adultos polimórficos.

Nymphs of Leptocorisa chinensis Dallas were reared on seed heads of various plant species to investigate this bug’s host range. Hatched nymphs were released onto gramineous and nongramineous species. Twenty-four hours after release, the percentage of nymphs that had settled on the plants varied from >90% in all but one gramineous species to 50% or less in the nongramineous species. It is therefore considered that nymphs can discern gramineous plants from nongramineous plants. Nymphs were reared until adult emergence, and the survivors were counted. Nymphs that had been reared on Oryza sativa L. (rice), Digitaria ciliaris (Retz.) Koeler, Poa annua L., or some other gramineous species were able to grow to adulthood, whereas nymphs that had been reared on some other gramineous species such as Eleusine indica (L.) Gaertn., Paspalum dilatatum Poir., Elymus racemifer (Steud.) Tzvelev, Bromus catharticus Vahl, or nongramineous species were not able to grow to adulthood. Results indicate that suitable plant species for the development of nymphs are restricted to a fraction of all gramineous species. Among food gramineous plants, summer plant species that bear seeds in reproductive season of L. chinensis retained high survival rates in young instars compared with spring plant species.

As part of an analysis of the genetic structure of Aphis gossypii Glover, one of the most polyphagous aphids and a pest of global agricultural importance, the ITS2 rDNA region was sequenced and compared among 38 Japanese aphid clones with different life cycles, host preferences, and insecticide susceptibilities. The preference of each clone for cucumber (Cucumis sativus L.), eggplant (Solanum melongena L.), citrus (Citrus unshiu Marcovitch), and pear (Pyrus pyrifolia Nakai) as a host was tested. About two thirds of the clones preferred cucumber or eggplant. No other particular combination of host plants was preferred. Five types of life cycle were found: holocyclic I, holocyclic II, intermediate, androcyclic, and anholocyclic. Each clone showed a different level of susceptibility to each of three insecticides. Apparent correlation between the various attributes was not found. Phylogenetic trees constructed from internal transcribed spacer 2 sequences showed ambiguous relationships between genetic differentiation and host preference.

We studied the life history of the caddisfly Neophylax rickeri Milne (Trichoptera: Uenoidae) in two coastal northern California (Marin Co.) streams, Redwood Creek (a third order stream) and Webb Creek (a first order stream). Features were described for egg (oviposition location, predation, and egg mass phenology), larval (instar determination, instar phenology, voltinism, and case building), pupal (prepupal diapause, pupation phenology, mortality, and predation), and adult (emergence phenology, sex ratios, protandry, size, and longevity) stages. Oviposition on the downstream-facing sides of rocks occurred primarily in November in both streams; however, egg masses were also present from April through November in Webb Creek. Egg masses in Redwood Creek, but not Webb Creek, sometimes contained an egg predator, Acanthocnema sp. (Diptera: Scathophagidae). N. rickeri has five instars. The Redwood Creek population exhibits a synchronous univoltine pattern of development, but in Webb Creek a more variable pattern is present, with the majority of the population being univoltine with a small bivoltine summer generation. The Redwood Creek population had a longer prepupal diapause, but a shorter emergence period than Webb Creek. Prepupal mortality was highest in the summer in Redwood Creek, but it was overall low in Webb Creek. Pupal and adult sex ratios indicated protandry, with males emerging before females by ≈2 wk in both streams. The differences in the life histories of N. rickeri between streams for voltinism, life cycle timing, mortality, and pupal diapause suggest that physical habitat differences likely influence the variation in life history of this species.

Diaphorina citri Kuwayama, a psyllid vector of huanglongbing (citrus greening disease), exhibits three more or less distinct abdominal colors in the adult psyllid: gray/brown, blue/green, and orange/yellow. We explored the daily (in individuals in the laboratory) and seasonal (in a field population) patterns in abdominal color of adult D. citri to clarify the biology of this species in relation to abdominal color and investigated the relationship between abdominal color and the reproductive state of adults (i.e., whether an individual is reproductively mature, has mated, or—in females—is gravid). Females were predominantly blue/green throughout their lives, with a small portion of individuals being gray/brown, especially just after emergence. Approximately 86% of mated females developed an orange/yellow abdominal color after mating, but they ultimately turned back to blue/green within several days to 1 mo after mating. Only 31% of virgin females turned orange/yellow. Males were predominantly blue/green early in life, but a greater portion of males relative to females were gray/brown. The orange/yellow color in females reflected the presence of eggs in the abdomen; in males it seemed to derive from the color of the internal reproductive organs, and it was generally only evident in older males. The preponderance of blue/green females, rarity of gray/brown females relative to gray/brown males, and rarity of orange/yellow males and females was largely reflected in sticky card trap captures from the field. Abdominal color is of essentially no value in discerning the state of sexual maturity and of only limited value in discerning whether females have mated.

The impact of the plant growth regulator gibberellic acid (GA₃) on parasitoid development and reproduction was examined using the endoparasitoid Apanteles galleriae Wilkinson (Hymenoptera: Braconidae). The effects of GA₃ were assessed by rearing A. galleriae on hosts fed the growth regulator and then measuring a several life history traits: developmental time from egg to adult, adult longevity, body sizes, fecundity, and sex ratios. GA₃ treatment yielded dose-dependent changes in adult longevity and duration of development. For example, at GA₃ doses >10 ppm, the life span of both male and female adult wasps decreased by 19–23 d in comparison with parasitoids that developed on GA₃-free hosts. Likewise, the length of development from egg to adult emergence significantly increased when A. galleriae developed on hosts fed the growth regulator at doses >200 ppm. In contrast, GA₃ did not seem to alter adult body sizes, sex ratios, or fecundity, with the exception that F₂ progeny production decreased by >40% at high concentrations (≥200 ppm). The potential significance of plant growth regulators on natural enemies used in integrated pest management programs is discussed.

Data on the chemical composition of the aphid epicuticle are scarce and often incongruent depending on the methodological parameters of the extraction and chemical analysis. This study aims to provide a chemical characterization of the epicuticular lipids of the English grain aphid, Sitobion avenae (F.) (Hemiptera: Aphididae). First, our results showed that the adsorption chromatography on a silica gel column is suitable to separate the hydrocarbons from more polar constituents found in the extract (e.g., wax esters, alcohols, and aldehydes). Then, we showed that other compounds not detected in previous analysis are likely to be constituents of the extract. Through a transesterification reaction, we demonstrated that the extracts produced numerous fatty acid methyl esters that can come either from long chain wax esters or fatty acid parts of cuticular acylglycerols. The possible semiochemical value of the wax esters and other long chain compounds is discussed. This study opens new insight on the identification of host recognition chemical cues by the parasitoids.

The bug Ischnodemus variegatus (Signoret) (Hemiptera: Blissidae) is an adventive herbivore, native to South America that feeds in the invasive grass Hymenachne amplexicaulis (Rudge) Nees (Poaceae). This grass is a problematic weed in Florida and Australia, but it is a highly valued forage in Mexico, Cuba, and Venezuela. We studied the influence of nine constant temperatures (8–38°C) on the developmental time and survival of I. variegatus. Complete egg and nymphal mortality occurred at temperatures ≤20.5°C and at 38°C. Developmental time decreased linearly with temperature until 28–30°C and then increased at 33°C. Mortality of first, second, and third instars was high across all temperatures. Developmental time across all temperatures was greatest for eggs, first and fifth instars compared with other stages. Linear and Brière-1 nonlinear models were used to determine the lower temperature threshold at which the developmental rate (1/D) approached zero. The lower thresholds to complete development (egg to adult) estimated with the linear and nonlinear model were 14.6 and 17.4°C, respectively. The total degree-days required to complete development estimated by the linear model was 588. Using temperature data from Florida, a map was generated to project a prediction grid of I. variegatus generations per yr. Based on these predictions, the insect can complete three to five generations per year in areas currently invaded in Florida. Results of this study will be used to understand the potential distribution and population growth of I. variegatus in H. amplexicaulis infested regions.

Diapause in Microplitis mediator Haliday (Hymenoptera: Braconidae) is manifested during the pupal stage and normally occurs during the winter season because of a photoperiodic response that is highly dependent on temperature. No diapause was observed at temperatures above 20°C regardless of the photoperiod. Only a small part of the population entered diapause at 20°C under short daylengths of light:dark 8:16–12:12. In contrast, when larvae were exposed to 16, 18, and 20°C combined with a photoperiod of 10:14, the percentages of parasitoids that entered pupal diapause was 97.9, 87.8, and 26.2%, respectively. Critical photoperiods were determined to be 7.03:16.97 and 12.21:11.79 at 16°C and 6.75:17.25 and 12.03:11.97 at 18°C. The second instar of the parasitoid was the most sensitive to diapause induction for the photoperiods and temperatures tested.

Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is a Neotropical species found from Argentina to the United States of America. In its distribution area, two genetically distinct strains are found that differ in their plant host distribution. The strains are morphologically identical, and they can only be reliably distinguished by molecular markers. In this study, we characterized caterpillars collected in corn, Zea mays L., and rice, Oryza sativa L., plantations in the state of Rio Grande do Sul, Brazil. The mitochondrial haplotype typical of the rice strain was found in 100% of the caterpillars collected from that crop, whereas 83% of the caterpillars obtained from corn were of the corn strain haplotype. A sex-linked tandem repeat element called FR was previously shown to have a strain-biased distribution in North American populations. We demonstrated that the same element is found in Brazilian fall armyworm and that it also organized in large tandem repeat clusters that are most frequently observed in caterpillars collected from rice and that display the rice strain mitochondrial haplotype. These results indicate that the Brazilian and North American fall armyworm populations are virtually indistinguishable with respect to the known genetic markers that are diagnostic of strain identity. Furthermore the data are consistent with other studies suggesting substantial gene flow between these widely separated populations. The strain-biased distribution of the FR element makes it a potentially useful marker to estimate interstrain hybridization frequencies of this species in Brazil.

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), considered as one of the most important agricultural pests, is broadly distributed around the world. From its presumed origin in Africa, the fly spread to several areas in Europe and, over the past 100 yr, to Australia and the Americas. We performed an extensive sampling of Mediterranean fruit fly populations in Argentina, covering most fruit-producing areas. The collection was studied using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and sequencing of ND4 and ND5 genes in the mitochondrial genome. We followed the standard system of nomenclature devised previously for designating mitochondrial haplotypes. Our results revealed 1) a high frequency of the already reported AAC and BBB haplotypes; 2) the presence of the AAB haplotype at very low frequency not previously detected in Argentina; 3) a novel point mutation defining two variants of the AAB haplotype (AABA and AABB), and 4) the presence of the AAA haplotype, only in insects of the strain used in the sterile insect technique. A PCR-RFLP assay was developed to differentiate the AABA and AABB haplotypes. The sequence analysis suggests that the AAC haplotype is most likely derived from the AABA haplotype by one nucleotide change. Inferences about the origin of Mediterranean fruit fly populations in this country are discussed.

Two strains (corn and rice) of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), have been identified that differ in their host plant preferences and performance. Although these strains have been shown to be partially reproductively incompatible, the geographic and host-related variability within them has received less attention. In the current study, fall armyworm larvae were collected from a variety of different hosts and from six provinces in Argentina. The following populations were established in the laboratory: Salta province (corn), Tucumán province (corn, alfalfa, soybean, wheat, and weeds), Santiago del Estero province (corn and alfalfa), Chaco province (weeds), Santa Fé province (corn), and Buenos Aires province (corn). The populations were characterized with respect to egg, larval, and pupal duration; pupal mass; adult longevity; sex ratio; number of spermatophores per female; preoviposition; oviposition and postoviposition period; number of eggs and egg masses per female; and egg viability. Small but significant differences were observed among the populations collected from different hosts within Tucumán province with respect to the duration of different life stages, pupal mass, and reproductive characteristics. Similarly, small but significant differences were observed among the populations collected from corn in different provinces. Reproductive compatibility studies also were conducted among the different fall armyworm corn populations, looking at the same reproductive parameters, as well as adult longevity. Fall armyworm populations from the north of the country showed no incompatibility among populations. However, indications of incompatibility were observed between the northern populations and a geographically distinct population from Buenos Aires.

RESUMEN Dos biotipos (maíz y arroz) del “cogollero del maíz”, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), fueron identificados por sus diferencias en las preferencias de las plantas hospederas y sus parámetros de vida. Si bien estos biotipos mostraron ser incompatibles reproductivamente en forma parcial, la variabilidad relacionada a aislamiento geográfico y a las plantas hospederas dentro de estos biotipos no SE estudiaron en profundidad. En este estudio SE colectaron larvas del cogollero del maíz de diferentes plantas hospederas y en seis provincias de Argentina. Se establecieron las siguientes poblaciones en el laboratorio: Salta (maíz), Tucumán (maíz, alfalfa, soja, trigo y malezas), Santiago del Estero (maíz y alfalfa), Chaco (malezas), Santa Fé (maíz) y Buenos Aires (maíz). Se caracterizaron las poblaciones con respecto a duración del estado de huevo, larva y pupa, peso de las pupas, longevidad de los adultos, proporción de sexos, número de espermatóforos, período de preoviposición, oviposición y postoviposición, número de huevos y posturas por hembra, número de huevos por postura y viabilidad de los huevos. Se encontraron diferencias significativas pero de poca magnitud entre las poblaciones colectadas de las diferentes plantas hospederas en la provincia de Tucumán con respecto a la duración de los diferentes estados del ciclo de vida, peso de las pupas y características reproductivas. Del mismo modo, al analizar las poblaciones colectadas en maíz pero de distintas provincias SE encontraron diferencias significativas para las variables analizadas. También SE estudió la compatibilidad reproductiva entre las poblaciones colectadas en maíz, analizándose los mismos parámetros reproductivos y la longevidad de los adultos. Las poblaciones del cogollero del norte del país no mostraron incompatibilidad entre ellas. Sin embargo, SE evidenciaron signos de incompatibilidad entre dichas poblaciones y una población geográficamente distante proveniente de la provincia de Buenos Aires.

This study examined how the size of host pupae of Musca domestica L. and exposure of host spiracles affected parasitism and sex ratio of Muscidifurax zaraptor Kogan & Legner (Hymenoptera: Pteromalidae). Based on a model by Charnov et al. (Nature [Lond.] 289: 27–33, 1981), we predicted that a lower proportion of female offspring would be produced on large hosts when large hosts were presented alone than when both small and large hosts were presented simultaneously. This prediction was supported, suggesting that females used relative cues for determining host size. We also predicted a greater proportion of female eggs would be produced on small hosts when only small hosts were presented than when both small and large hosts were presented simultaneously. This prediction was not supported, suggesting that females also used absolute cues for assessing host size. Host size had no significant effect on the thorax widths of offspring. However, the head widths of offspring varied with pupal size, with wasps emerging from large pupae having larger thoraces. There was a difference in parasitism depending on pupal orientation; house fly pupae that had posterior spiracles exposed (i.e., anterior spiracles concealed) were less often parasitized than when the anterior spiracles were exposed. Pupal position and sex ratio were not related. Finally, females spent less time drilling through posterior spiracles than through anterior spiracles.

The effect of prior oviposition experience on the avoidance of superparasitism was investigated in the solitary endoparasitoid Fopius arisanus (Sonan) (Hymenoptera: Braconidae), a highly successful biological control agent of tephritid fruit fly pests. Individual female wasps, either naïve or having prior egg-laying experience in unparasitized hosts, were allowed to sequentially visit two coffee berries, each infested with a clutch of host eggs of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). One of the two berries had been previously exploited by a conspecific female or the test-female herself. The wasp was allowed to visit the previously exploited or unexploited berry first while either in the presence or absence of a conspecific female. Naïve wasps readily accepted previously parasitized hosts only when they visited the previously exploited fruit first. In contrast, wasps that had experienced prior oviposition, and wasps that visited the unexploited berry first, never accepted previously parasitized hosts, even when the test wasps contained relatively high egg-load or had been exposed to hosts in the presence of conspecific females. These results demonstrate a dramatic effect of egg-laying experience on the avoidance of superparasitism by this parasitoid. We discuss the adaptive value of avoiding superparasitism in relation to the mechanism of intraspecific competition in this species.

Behavior and sounds associated with mating of mass-reared irradiated and untreated (nonirradiated) Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) males were analyzed from synchronous acoustic and video records. The flies tested were from a population used in sterile release programs that help maintain fruit-fly-free areas in Australia. Males typically produce “calling,” “courtship,” and “copula” sounds as mating progresses. Calling sounds are variable-duration bursts of wing vibrations produced before the male orients toward the female. Rapid bursts of courtship sounds of relatively constant duration are produced after orientation toward the female. Copula sounds of variable amplitude and duration are produced after mounting. There was a significant negative correlation between courtship wingbeat frequency and wing width of untreated males, and those that copulated had a lower frequency than those that failed. Wingbeat frequencies in flight, calling, courtship, and copula sounds were significantly correlated within flies, possibly because they all are produced by the same flight motor, with amplitudes affected by the positioning of the wings relative to “stops” on the thorax. The temporal patterns of calling and courtship sounds differed significantly between irradiated and untreated males. Irradiation is known to damage insect central nervous system interneurons and thereby alter the coordination and timing of behavioral activities, but this is the first study identifying an effect of irradiation on tephritid calling and courtship sounds. Although differences in temporal patterns of calling and courtship sounds have potential to affect mating competitiveness, no differences were observed in proportions of irradiated and untreated males that copulated in the laboratory.

Male and female codling moths, Cydia pomonella (L.) (Lepidoptera: Tortricidae) responded to fruit-baited traps in orchards. Numbers of codling moths trapped with immature uninfested apples (Malus spp.), immature apples infested with larval codling moth, fresh ripe apples, stored ripe apples, or fresh ripe pears (Pyrus spp.) were significantly greater than in unbaited traps. Greatest numbers of codling moths were captured in traps baited with ripe ‘Bartlett’ pears, but direct comparisons of these fruit types were not made. Females captured in traps baited with ripe apples or pears were primarily mated and had developing or mature eggs, and smaller numbers of females trapped were unmated without eggs or were postreproductive. Volatile compounds sampled from infested immature ‘Red Delicious’ apples that were attractive in traps showed emission of two known codling moth host kairomones: (E,E)-α-farnesene as well as small amounts of β-caryophyllene. Collections of volatile chemicals from ripe ‘Braeburn’ apples that were attractive in traps showed strong emission of the codling moth kairomones 2-methylbutyl acetate, butyl hexanoate, hexyl hexanoate, and (E,E)-α-farnesene, and very small amounts of the kairomones (R)-limonene and (E)-β-farnesene. Volatile collections made from ripe Bartlett pears that were attractive in traps indicated strong emission of the codling moth kairomones butyl hexanoate, ethyl (E,Z) 2,4-decadienoate and (E,E)-α-farnesene, and small amounts of the kairomones 2-methylbutyl acetate, hexyl hexanoate, β-caryophyllene, (E)-β-farnesene, and (E,E)-farnesol.