The leafmining fly Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) is an important pest of vegetable and cut-flower crops. In recent decades, this species has become invasive, spreading from the Americas to the rest of the world. Despite substantial losses caused by Liriomyza leafminers, the systematics of these flies has remained poorly understood because of their small size and morphological homogeneity. Previous molecular research on other polyphagous Liriomyza pests has suggested that cryptic species may be present. Here, we use mitochondrial cytochrome oxidase I sequence variation to investigate phylogeographic structure within L. trifolii. Our results indicate that L. trifolii harbors distinct phylogenetic clades, suggesting the presence of cryptic species. There is also evidence of a recently derived, highly specialized pepper (Capsicum spp., Solanaceae)-feeding population within L. trifolii that may represent a host race or even a distinct species. Introduced populations from various locations contained a highly restricted subset of the mitochondrial variation present within L. trifolii, suggesting one or more bottlenecks during colonization.

The South American rice miner, Hydrellia wirthi Korytkowski (Diptera: Ephydridae), a recently discovered, invasive pest of rice, Oryza sativa L., is reported from southeastern United States (Louisiana and Texas). A detailed description and diagnosis with illustrations and photographs are provided to facilitate identification, along with descriptions of its damage as a miner in rice whorls, stems, and leaves. The localities where this invasive species has been found in Louisiana and Texas are provided.

Two new carabid beetle species, Pristosia impunctata and P. latistoma (Coleoptera: Carabidae), are described from South Korea. The phylogenetic relationships among five Korean and Japanese Pristosia species are reconstructed based on a cladistic analysis of 29 morphological characters.

On the basis of head capsule widths (HCWs) of field-collected and laboratory-reared larvae, the moth Gynaephora menyuanensis Yan & Chou (1997) (Lepidoptera: Lymantriidae) was first found to have six instars in the male and seven instars in the female. Mean HCWs were 0.68, 0.91, 1.22, 1.58, 2.06, 2.69, and 3.45 mm in field-collected larvae and 0.67, 0.87, 1.17, 1.54, 2.00, 2.59, and 3.24 mm in laboratory-reared larvae for first through seventh instars, respectively. Stadium duration, body length, and body mass of each instar also were examined. The first, second, third, fourth, fifth, sixth (♀, ♂), and seventh (♀) instars averaged 240.30, 15.32, 14.58, 14.74, 13.86, 15.90 (♂), 13.65 (♀) and 16.28 (♀) d in stadium duration; 3.95, 4.96, 6.07, 9.14, 13.31, 17.23, and 25.79 mm in body length; and 1.33, 3.46, 7.79, 17.32, 45.05, 103.07, and 217.24 mg in body mass under the field conditions. Analyses of the results showed highly significant exponential correlations of HCW with body length and body mass, and power function correlations of instar with HCW, body mass, and stadium duration, and S correlations of instars with stadium duration. A life cycle of G. menyuanensis required a year in the field, and the mean developmental time observed from egg to adult was ≈346 d in the male and 350 d in the female. Because abiotic and biotic environments of Tibetan-Qinghai Plateau are similar to Arctic tundra, with long severe winters and short cool summers, we compared HCW, body length, body mass, and stadium duration of G. menyuanensis with two congeneric species occurring in the Arctic, Gynaephora groenlandica (Wöcke) and Gynaephora rossii (Curtis) body mass.

Antispila distyliella sp. nov. (Lepidoptera: Heliozelidae) is described from the Ryukyus, Japan, with biology and morphology of adult and immature stages given. The larva feeds on the leaves of Distylium racemosum Siebold & Zuccarini (Hamamelidaceae), which is a new host plant family for Heliozelidae. The morphology, including chaetotaxy, of the premature (sixth instar) and mature (seventh instar) larvae is described in detail for the first time for Heliozelidae. The final instar, which is a nonfeeding stage in the larval case, has a smaller head, shorter body, and shorter setae than the penultimate instar.

A key was developed using morphological and behavioral characters to identify nine genera and 13 species of protists found in the hindgut of three Reticulitermes species— Reticulitermes flavipes (Kollar), Reticulitermes virginicus (Banks), and Reticulitermes hageni Banks—by using the online IDnature guides by Discover Life. There are seven characters and 13 taxa, each attached to species descriptions, digital stills, or movies to aid in protist species identification. We chose characters for protist species identification that were easy to observe with live samples and a light microscope at 400× magnification. All 11 protists from R. flavipes and nine each in R. virginicus and R. hageni were recognized using original and revised species descriptions. This was the first report of the protist genera Trichomitus from both R. virginicus and R. hageni.

Ambrosia-feeding scolytids in the Xyleborina are the most abundant exotic bark beetles in North America. Many new species discoveries and taxonomic changes have occurred since their last review in 1982. The need for a worldwide revision of this tribe hampers the ability to identify species. To remedy this situation, an illustrated key is constructed and Xyleborus glabratus Eichhoff, Xyleborus similis Ferrari, and Euwallacea fornicatus (Eichhoff), which are new to North America, are reported and diagnosed. In addition the key is presented in electronic format with additional illustration ( http://scolytid.msu.edu) to increase worldwide availability and accommodate future taxonomic revision.

Three new species of eriophyid mites on bamboo from the Qinling Mountains, northwestern China, are described and illustrated: Tegolophus bashaniae sp. nov. on Bashania fargesii (E. G. Camus) Keng f. et Yi (Poaceae: Bambuseae); Tegolophus fargesiae sp. nov. on Fargesia qinlingensis Yi et J.X. Shao, and Tetraspinus vulgaris sp. nov. on Bambusa vulgaris Schrader ex Wendland. All species are vagrants on leaf surfaces, causing no apparent damage. A key to known eriophyid mites on bamboo from China is provided.

Study of the South African endemic Quedius sexpunctatus Bernhauer, 1917 revealed a complex of four very similar species, here referred to as the Q. sexpunctatus group, three of them described as new. Although superficially similar to Quedius, members of the Q. sexpunctatus group differ significantly, in some morphological characters, from all other members of that genus, but they do not display any other affiliation within the tribe Staphylinini. To assess the position of these “Quedius” within the system of the tribe, a parsimony-based phylogenetic analysis was conducted using 63 morphological characters for a taxon sample, including 10 species representing the genus Quedius, 24 species of other genera of the subtribe Quediina, 11 species from other subtribes of the tribe Staphylinini, and one species each of the tribes Maorothiini, Platyprosopini, and Arrowinini (altogether 48 terminal taxa). It showed that the Q. sexpunctatus group is a relatively basal lineage of Staphylinini, rather remote from the genus Quedius, and neither the latter, nor the whole subtribe Quediina, is monophyletic. The whole phylogenetic pattern yielded by the analysis, briefly discussed in the article, disagrees with the current conventional classification of the tribe Staphylinini. To translate the newly obtained phylogenetic information into the system, the new genus Afroquedius is proposed to accommodate the Q. sexpunctatus group. Other, more radical taxonomic changes suggested by the analysis are postponed pending a broader and more rigorous study with more extensive coverage of the tribe Staphylinini, for which this article is a stepping stone. A lectotype is designated for Quedius sexpunctatus Bernhauer, the type species of Afroquedius. The key to all known species of Afroquedius is provided.

Diapause in the boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae), remains a contentious issue despite intense investigation. In particular, the roles and interactions of photoperiod, temperature, and adult diet are poorly understood. We reexamined the influences of these factors by using a feeding regime typical of previous studies (group, one square per five weevils per day) as well as one known to promote reproductive development (single, one square per weevil per day). Three separate studies each incorporated all combinations of the following: photoperiod (short day, 11:13; long day 13:11 [L:D] h), temperature regime (constant 29.4°C; warm day, cool night, 29.4°C:10°C [day:night]), feeding regime, and age at dissection (3, 6, 9, and 12 d after adult eclosion). Studies differed in the source of weevils (Lower Rio Grande Valley, Brazos Valley of Texas), and the photoperiod used to rear weevils to adulthood (11:13 or 13:11 [L:D] h). Interpretable effects of photoperiod on diapause induction were not observed. Cool nights delayed development of fat bodies, oocytes with yolk, and the occurrence of diapause, especially in weevils fed in groups. However, these effects were not apparent by day 12. The most marked responses were to feeding regime. Hypertrophied fat bodies and diapause generally occurred more often, and oocytes with yolk less often, for weevils fed in groups compared with those fed singly. Fundamental differences in diapause response corresponding to rearing conditions or source of weevils were not observed. These results suggest improved understanding of the dynamics of adult diapause could be achieved through continued investigation of the effects of adult diets.

There are several species of subterranean termites in the United States, some of which occur sympatrically over broad geographic regions. However, there is little information on the relative abundance of the different species or the extent to which they differ with respect to colony social and spatial organization. We used microsatellite markers to investigate the relative numbers of colonies, to infer colony breeding structures, and to delineate colony foraging areas in four species of subterranean termites occurring in a state park in Charleston, SC. The two most abundant species, Reticulitermes hageni Banks and Reticulitermes flavipes (Kollar), which together accounted for 80% of the 49 colonies sampled, had fairly localized foraging ranges of <30 m across. In contrast, Reticulitermes virginicus (Banks) and the Formosan subterranean termite, Coptotermes formosanus Shiraki, had far fewer colonies, but these colonies were more expansive, spanning distances >100 linear m. Colonies of all species were primarily simple families each headed by a single monogamous pair of reproductives. Generally, the remaining colonies of each species were consistent with being extended families, i.e., headed by multiple neotenic reproductives descended from simple families. Only in R. flavipes was a mixed family colony detected, with workers from two distinct families occurring together. These results from molecular markers reveal how the various species in a relatively diverse subterranean termite community can vary in abundance, size of colony foraging area and breeding structure, thereby setting the stage for subsequent studies to identify the factors shaping these communities.

One of the leading concerns for both conservation biology and forestry has been how forest fragmentation affects biodiversity, and how forestry practices can be altered to mitigate diversity losses. However, the effects of habitat fragmentation on ecological functional groups within diverse taxa such as Lepidoptera are poorly known, particularly in boreal forests. We assessed landscape-level changes in moth species richness and abundance in relation to forest fragmentation, measured at multiple scales. We assessed fragmentation effects on three functional groups: tree- and shrub-feeding species, grass- and forb-feeding species, and species that act as hosts for parasitoids of an important forest defoliator, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae). Total species richness showed a significant decline as a function of fragmentation at all measured spatial scales; both polynomial and threshold models tended to explain more variation than linear models, suggesting that there is little to no change in overall moth diversity between low and moderately fragmented stands. However, changes in diversity patterns within functional groups showed that total diversity measures may mask changes in community structure. Changes in overall diversity were driven largely by a decrease in species richness of tree- and shrub-feeding moths, although forb- and grass-feeding moths also showed marginally lower species richness at high fragmentation levels. Most species of the parasitoid host group decreased in abundance with increasing fragmentation. These findings show that overall diversity measures can mask important community changes, and that the optimal landscape scale at which these changes are measured is taxon dependent. Finally, the decrease in host availability to M. disstria parasitoids in fragmented forests may exacerbate population outbreaks of M. disstria.

Anaphes victus Huber (Hymenoptera: Mymaridae), an egg parasitoid of weevils (Curculionidae), has a North American distribution and displays genetic variability among populations from different locations. Local adaptation to temperature was compared among three A. victus ecotypes originating from different latitudes: Texas, Michigan, and Québec. Development occurred between 11.5 and 34.0°C for all ecotypes and was accurately described by sigmoid curves. Some adaptations of A. victus to local climatic conditions were found, because the Texas ecotype had a higher developmental rate at the temperature of maximal developmental rate (T_m) than both northern temperate ecotypes and it developed faster at high temperatures. In contrast, the ecotypes from Michigan and Québec displayed faster developmental rates at low temperatures. In contrast to the Texas ecotype, both northern ecotypes have T_m values above the average maximum temperatures of their original habitat. These results are discussed in the context of evolutionary constraint that could have restricted the adaptation of the developmental process in A. victus. Lower developmental thresholds were similar across ecotypes and sexes, an indication that this parameter may not be subjected to local adaptation. For each ecotype, males required fewer degree-days than females to complete their immature development.

Adults of the rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), were collected from three sources: 1) overwintering sites near rice, Oryza sativa L.; 2) a light trap placed in grassy vegetation and fallow fields; and 3) flooded rice plots near Beaumont, TX, from mid-April to late May 2005. Their color morph and reproductive status were surveyed. Frequency of the dark morph (36.0, 45.8, and 31.6% at each collection source, respectively) was significantly lower than that of the light morph (64.0, 54.2, and 68.4% respectively). Dark males accounted for only 3.5–7.4% of the populations, significantly less abundant than light males (28.8–32.0%) in each collection source. The morph frequency changed significantly with season in females, but not in males. Female-biased sex ratios were observed with the proportion of females to males being 1.5, 2.1, and 1.9 at each collection source, respectively. In most collections, ovarian development and mating status were similar between the females of different morphs, suggesting that elytral morph in this weevil might not be related to female reproductive development.

We investigated the tritrophic interactions among southwestern dwarf mistletoe [Arceuthobium vaginatum (Willd.) Presl subsp. cryptopodum], mistletoe herbivores, and host pine (Pinus ponderosa Dougl. ex Laws. and C. Laws. variety scopulorum Engelm.)-associated predators. In an observational study, we characterized differences in pine-associated arthropods and pine branch morphology between branches either parasitized by mistletoe (brooms) or not visibly infected. Compared with noninfected branches, brooms had a more reticulate branching structure, collected 36 times more dead needles and supported 1.7 times more arthropod predators. In a manipulative field experiment, we investigated whether pine-associated predators fed upon lepidopteran herbivores of mistletoe and thereby reduced herbivore damage to the parasite. Over a 30-d trial, herbivores fed upon approximately two-thirds of available mistletoe shoots. Predator removal increased herbivore survival by 56% but had no detectable effect on the level of herbivory damage. We speculate that herbivores compete for mistletoe shoots and that increased per-capita feeding compensated for predator reduction of herbivore abundance. In summary, our results demonstrate that mistletoe parasitism altered the pine arthropod community, including an increase in the density of predators that likely feed upon mistletoe herbivores.

We were interested in determining the feeding response of the Caribbean fruit fly, Anastrepha suspensa (Loew) (Diptera: Tephritidae), to various sugar concentrations to develop an improved bait for adults. We compared the consumption of 0.01–1.00 M concentrations of glucose, fructose, raffinose, and sucrose in no-choice tests for 24-h- and 6-d-old male and female flies. Sucrose was the most consumed sugar or within the most consumed group of sugars at 0.02–0.20 M concentrations. There were no differences in consumption among sugars at 0.01, 0.40, and 1.00 M. Consumption generally increased with increasing sugar concentration except that sucrose consumption peaked at 0.20 M. Twenty-four-hour-old females consumed less fructose than other sugars; 24-h-old males consumed more sucrose than fructose or raffinose with an intermediate response to glucose. Females in the 6-d-old group consumed more sucrose than the other three sugars, whereas 6-d-old males exhibited no difference in consumption among sugars. In choice tests, flies consumed more sugar solution than water, but the difference between 0.20 M fructose and water was not significant for 24-h-old males or females. In choice tests between 0.20 M fructose and 0.20 M sucrose, both 24-h- and 6-d-old females showed a preference for fructose. Males of both age classes showed no preference. These results indicate that the responses of flies to different sugars can vary by sugar, gender, and age.

The biology of the bromeliad-eating weevil Metamasius mosieri Barber (Coleoptera: Dryophthoridae) was studied under laboratory conditions of 25°C, 50–60% RH, and a photoperiod of 14:10 (L:D) h. Mean duration of the egg, larval, and pupal stages was 8.2, 59.6, and 9.7 d, respectively. Mean adult longevity was 36.1 wk for females and 50.2 wk for males. Females produced on average 39.2 eggs during their lifetime. The larval and pupal stages are described, and characters for distinguishing the pupae of M. mosieri and Metamasius callizona (Chevrolat) are contrasted and illustrated. Oviposition behavior is described. The weevil is known to be present in 13 south Florida counties.

Oviposition of Graphocephala atropunctata (Signoret) (Hemiptera: Cicadellidae), the blue-green sharpshooter, was assessed on wild grape, Vitis girdiana Munson, in southern California. Female blue-green sharpshooter preferred to oviposit into new growth, primarily succulent young grape tendrils and canes. The midrib and petioles of small grape leaves also were used for oviposition, but to a lesser extent. Mature canes, and medium- and large-sized leaves were not used for oviposition. Two parasitoids, Gonatocerus latipennis Girault and Polynema sp. (both Hymenoptera: Mymaridae) were reared from field collected blue-green sharpshooter eggs. Polynema sp. and G. latipennis constitute the first documented egg parasitoids of blue-green sharpshooter. Deployment of sentinel plants and reciprocal tests were implemented and further confirmed the parasitization of blue-green sharpshooter eggs by these two parasitoid species. Yellow sticky card trap catch of adult blue-green sharpshooter was significantly correlated to combined blue-green sharpshooter nymphal and Polynema sp. emergence in 2004, but not in 2005. A degree-day model was developed for onset of blue-green sharpshooter flight activity and emergence in the field.

Partial sequencing of mitochondrial DNA in the cytochrome oxidase subunit I gene of larvae, pupae, and reared adults confirmed that Asphondylia sphaera Monzen (Diptera: Cecidomyiidae) induces fruit galls on Ligustrum obtusifolium Siebold and Zuccarini, Ligustrum japonicum Thunberg, Ligustrum lucidum Aiton, and Ligustrum ovalifolium Hasskarl (Oleaceae) in Japan. In addition, part of the population of A. sphaera diverted into a short-season generation on flower buds of Rhus succedanea L. and Rhus sylvestris Siebold and Zuccarini (Anacardiaceae), and L. japonicum as short-term alternative host plants or host organs other than fruit of Ligustrum species that are the main host organs. This situation is considered to be another type of polyphagy in addition to the host alternation that has been already documented in some Asphondylia species.

Patches of forest in the western Amazon often are converted to small-scale subsistence plantations (chacras), which become early successional forest (purma) when abandoned. Differences in abiotic conditions and phytotelm characteristics among chacras, purmas, and adjacent forest likely influence the distribution of phytotelm colonists. We sampled the contents of natural water-filled tree holes in the three habitat types and quantified differences in the abundance, species richness and composition of their macroinvertebrate communities. We additionally placed experimental tree-hole analogs (water-filled bamboo [Guadua sp.] internodes) in each of the habitat types and sampled their macroinvertebrate communities over 110 d. The species composition of macroinvertebrates in both tree holes and bamboo sections differed among habitats. Larvae of damselflies and crane flies, both important predators of mosquitoes, were replaced by larvae of the predatory mosquito Toxorhynchites spp. in chacras. Several mosquito species were relatively more abundant in chacra habitat. Macroinvertebrate abundance and species richness were correlated with water volume in tree holes and varied over time in bamboo sections. Species richness in bamboo did not differ among the three focal habitat types, but forest tree holes contained more species than tree holes in chacras. Differences in species composition between the two types of phytotelmata largely were attributed to the short duration of the bamboo experiment.

RESUMEN Los bosques primarios de la Amazonía peruana están siendo deforestados para la agricultura de pequeña escala (chacras). Las chacras forman bosques secundarios (purmas) después de ser abandonados. Las características del agua almacenada en plantas (fitotelmata) y las condiciones abióticas son diferentes entre chacras, purmas y bosques primarios. Se colocaron segmentos de bambú con agua en los tres hábitats y se cuantificaron la abundancia, riqueza y composición de especies de macroinvertebrados durante 110 días. La abundancia y riqueza de macroinvertebrados, y la conductividad y el pH del agua de los bambúes variaron durante el estudio, pero no hubo diferencias de estos factores entre hábitats. También, se estudiaron la fauna de huecos en árboles que contienen agua en los mismos hábitats. Encontraron correlaciones entre el volumen del hueco y la abundancia y riqueza de macroinvertebrados, pero no entre estas variables y las características del agua (pH y conductividad). La composición de especies en los bambúes y los huecos no fue igual entre hábitats. Las larvas de libélulas y moscas (Tipulidae), que son los depredadores principales de los mosquitoes en este sistema, fueron reemplazados por otro depredador, el mosquito Toxorhynchites spp., en las chacras. Algunas especies de mosquitoes fueron proporcionalmente más abundantes en las chacras. Ligeras diferencias en la composición de especies entre los dos tipos de fitotelmata pudieron resultar del poco tiempo que duró el experimento con el bambú.

Invasive plants are generally thought to have negative impacts on native communities. Rarely, however, are the impacts of invasive plants on native insects examined, limiting our understanding of the broader effects of invasive plants on native habitats. In this study, I document the use of purple loosestrife, Lythrum salicaria L. (Lythraceae), an aggressive wetland invasive, by Hemileuca sp. (Saturniidae), a native silkmoth. This buckmoth is a unique ecological variant of the more widespread buck moth, Hemileuca maia (Drury), and is of conservation concern in some areas. Hemileuca sp. was regularly observed feeding on L. salicaria in 2003 and 2004 at two sites in southern Wisconsin. Densities of late instars were as high as 12 individuals/m² and caused significant defoliation of L. salicaria with an average 34% loss of foliage relative to undamaged plants. Experimental manipulations of Hemileuca sp. caterpillars showed that herbivory could decrease seed production as much as 66%. In a laboratory assay, Hemileuca sp. feeding on L. salicaria had significantly lower pupal mass and lower survivorship to pupation (24%) relative to larvae feeding on Salix foliage (90%). Moreover, in two-choice preference assays, larvae preferred Salix over Lythrum foliage. Populations of Hemileuca sp. were subject to intense parasitism (up to 93%) by a tachinid parasitoid, Leschenaultia flavipes (Bigot). This combination of factors suggests there may be significant negative selection on Hemileuca sp. feeding on L. salicaria and that invaded habitats may be ecological sinks for the native herbivores.

Larvae of Bactrocera dorsalis Hendel (Diptera: Tephritidae), the oriental fruit fly, were reared in a liquid diet without mill feed (a biological bulking agent) on a large scale for the first time. Sponge cloth was used as an inert diet-supporting material. Experiments were conducted to identify the rearing components for factory-scale liquid diet rearing based on the larval duration, pupal recovery, pupal weight, adult emergence, flight ability, mating, egg hatch, sex ratio, egg production, and egging duration. The up-to-date recommended rearing conditions using liquid diet are as follows: formula: basic liquid diet includes sugar (8.99%), yeast (15.06%), nipagen (0.15%), sodium benzoate (0.15%), wheat germ oil (0.15%), citric acid (1.70%), and water (73.81%); tray: lid of pupation fiberglass box; seeding egg density: 2.5 ml; diet volume: 1,250 ml; screen: coarse screen or optional depending on the tray design; water quality: tap water; and additives: 0.15% wheat germ oil or higher. Fruit fly performance from larvae reared in this liquid diet is identical to that from conventional mill feed diet, and preliminary tests show that liquid diet technology can be used at the factory scale.

Melittobia digitata Dahms (Hymenoptera: Eulophidae) is a gregarious ectoparasitoid that attacks the pupae of solitary bees and wasps. Although this wasp has been intensively studied in terms of behavior and life history, almost nothing is known about its venom. Moreover, the use of venom in the host–parasite relationship has been disputed despite observations that parasitized hosts seem to be halted in development and enter a state of paralysis. In this study, we examined the role of venom from M. digitata during parasitism by comparing the developmental fate of natural (alfalfa leafcutting bee, Megachile rotundata F.) and factitious [yellow mealworm, Tenebrio molitor L. and flesh fly, Sarcophaga bullata (Parker)] hosts after either natural envenomation or artificial venom injection. Isolated crude venom collected either by “milking” adult females or by dissections of venom glands was nearly equally effective in halting the development of M. rotundata, T. molitor, and S. bullata. Host responses to venom injection were dependent on the developmental stage of the host tested and concentration of venom injected. For all three hosts, venom seemed to induce paralysis, but the onset of paralysis was not the same in each host. T. molitor and M. rotundata entered a paralyzed state several hours (2–4) earlier than larvae of S. bullata. Likewise, the type of paralysis induced by venom from M. digitata was not the same for the three insects tested as evidenced by limited mobility and some progression of development in venom-injected M. rotundata and T. molitor, and a flaccid paralysis characterized by complete immobilization in larvae of S. bullata. Ultimately, all venom-injected hosts that became paralyzed eventually died. Our data suggest two potential modes of action for M. digitata venom.

Embryonic development in Diatraea saccharalis F. (Lepidoptera: Crambidae) has been studied by means of whole mounts, histochemical techniques, and light microscopy. Three embryonic stages were identified up to larval eclosion. In the first stage, 0–10 h, intense multiplication of energids occurred, and significant changes in RNA levels were detected in distinct zones before the start of blastulation. During the second stage, 10–24 h, new protein and RNA sites were detected in the egg’s periphery. This was probably because of migration of energids and formation of the blastula. Gastrulation occurs during this stage and is characterized by intense synthetic and mitotic processes. The third stage, 25–168 h, showed ortochromatic and metachromatic regions at the posterior pole and in the yolk, egg periphery, and body of the embryo. Organogenesis closes approximately on the sixth day when the embryo starts feeding on the remaining yolk. Its development is complete by the end of the seventh day on which the larva ecloses.

Analyses of population genetic variation in invasive species can provide information on the history of the invasions, breeding systems, and gene flow patterns. We surveyed genetic variation in both social forms of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), throughout the species’ introduced range in the United States, to learn how the unique breeding biology of each form shapes genetic structure at various scales, to discern genetic footprints of the invasion process, and to reconstruct the origin and spread of each form. Consistent with more limited earlier studies, our analyses revealed significant local mitochondrial DNA (mtDNA) differentiation in the polygyne (multiple colony queens) but not in the monogyne (single colony queen) social form as well as pronounced mtDNA differentiation coupled with weaker nuclear differentiation between sympatric populations of the two forms. At a larger scale, we found no mtDNA but significant nuclear regional differentiation. In general, populations were most similar to other populations of the same social form at their mtDNA genomes. These higher level patterns of structure are consistent with the spread of the ant by long-distance, human-mediated dispersal, with subfounder populations of each form typically established by queens of the same form. Bayesian analyses showed that study populations most distant from the claimed site of entry, Mobile, AL, have diverged most from the hypothetical founder population, consistent with an invasion scenario in which the ants spread outward from Mobile through repeated subfounder events. Several lines of evidence raise the possibility of secondary introductions of S. invicta into the United States.

The Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae), invaded eastern North America in 1985 and subsequently spread across a range of ≈14° latitude. We used a common garden, full-sib experimental design to assess population differentiation and quantify within-population genetic variance for larval growth rate, body size (=pupal mass), and preadult developmental period of three populations from each of Florida (≈27° N), Texas (≈29° N), and New Jersey (≈40° N) reared at both 16 and 26°C. Both larval growth rate and body size were affected by a three-way interaction between region (Florida, Texas, and New Jersey), temperature, and sex, indicating that regional differences depended upon both temperature and sex. We found consistent but weak trends toward increased larval growth rate, increased pupal mass, and decreased preadult developmental period in northern relative to southern populations. Among-family (genetic) variance of pupal mass was significantly greater in New Jersey than in Texas and Florida populations at 16°C but not 26°C. Among-family variance for larval growth rate and preadult developmental period did not differ among regions. These results are discussed with respect to the life history evolution of Ae. albopictus across its range in North America.

Life history theory predicts that current reproductive investment should increase as life expectancy decreases. We adapted the prediction to female mate choice behavior and examined the effect of life expectancy on two components of female choice of the cricket Meloimorpha japonica (De Haan) (Orthoptera: Gryllidae). We measured female responsiveness and female preference by using a two-choice playback experiment of male calling songs. Females with a shorter life span exhibited higher responsiveness to the male calling song. No significant effect of life span on female preference for male calling songs was found. We discuss the implications of these results for sexual selection and life history strategy.

We analyzed mate recognition and the cooperative behavior of male–female pairs in Canthon cyanellus cyanellus LeConte (Coleoptera: Scarabaeidae), a carrion-feeding scarab, during food ball rolling among five populations found in tropical forest fragments on the eastern coastal plains of Mexico. Sexual recognition in this species is mostly mediated by chemical cues. Intrapopulation and male–female pairs formed with individual from populations <400 km apart showed cooperative behavior (joint rolling of the food ball by both members). However, male–female pairs from populations >400 km apart showed no cooperative behavior (individual food ball rolling by one of the partners and fights), although they also rolled food balls together. In male–female pairs from the more distant populations (≥600 km apart), >50% fought for food balls. Brood ball production by females and the number of eclosed beetles from the northern population and from the crosses between individuals from the most distant populations were lower than those of other intra- or interpopulation combinations. Gas chromatograph mass spectroscopy of cuticular extract showed that the southern population had 48 surface compounds, 18 of them not present in the northern or intermediate populations. The intermediate population had 41 compounds, 11 of them exclusive. However, the northern population had 24 compounds and only one was exclusive. The lack of cooperative interaction among male–female pairs from distant populations, along with their reduced reproductive success and the differences in cuticular composition between populations, suggest that extreme populations of Canthon c. cyanellus are in a process of incipient speciation.