A revision of the Charis gynaea group of Neotropical riodinid butterflies is presented. We recognize eight species, including five that are described here: C. barnesi, C. callaghani, C. gallardi, C. nicolayi, and C. smalli. The taxa zama and candiope, previously treated as subspecies of Charis gynaea, are both returned to species status (stat. revs.), and the latter is excluded from the gynaea group. The taxon pyritis is synonymized with C. candiope (n. syn.). A cladistic analysis using seventeen characters of male and female genitalia and external facies generated a single most parsimonious cladogram indicating the existence of two clades, one containing smalli nicolayi and the other containing the remaining species. In the latter gynaea clade, all species except C. hermodora are distributed parapatrically throughout the Neotropics. An area cladogram indicates the historical relationships among endemic centers for this last group to be southeast Brazil (Guianas (Central America Amazon)). This hypothesis is compared with those generated for birds.

Phylogenetic analysis using DNA sequence data from two nuclear genes was undertaken to investigate phylogeographic structure within the widespread leafmining pest Liriomyza huidobrensis (Blanchard). Parsimony analysis of 171 bp from β-tubulin (including an intron) and 921 bp from elongation factor-1α confirms previous findings from mitochondrial sequence data of deep phylogeographic structure indicative of cryptic species within L. huidobrensis. We resurrect the name L. langei Frick for the North American cryptic species and restrict the name L. huidobrensis to the South and Central American cryptic species. Results from nuclear genes also confirm previous results suggesting that recent invasions of this leafminer in many areas of the world are due to the spread of L. huidobrensis from South or Central America.

Reciprocal double mating experiments were done between the northern banded (disruptively colored) form [Limenitis arthemis arthemis (Drury)] and the southern unbanded mimetic form [L. arthemis astyanax (F.)] of the banded purple butterfly. The results showed that following a second mating (and the successful transfer of a second spermatophore into the bursa copulatrix of each female), the first male continued to sire the subsequent progeny in five of 17 (29%) cases. The sequential double matings of these 17 different females with 34 different males resulted in full, partial, and unbanded wing phenotypes which were used as paternal genetic markers in this intergrading complex of butterflies. The containment of the spermatozoa within separate spermatophores at the time of mating normally resulted in only one effective sire. Among three broods (all one of four cross types) some sperm mixing may have occurred following the second matings, as evidenced by the occurrence of a few unbanded insects among progeny which otherwise were partially banded. The evolutionary implications of these findings are considered as they relate to insect mate-seeking strategies and individual fitnesses.

The leafhopper Sophonia rufofascia (Kuoh & Kuoh) is a recent invasive pest attacking a wide variety of plant species in Hawaii. We surveyed the distribution and parasitism of its eggs in a number of natural and agricultural habitats on the islands of Kauai, Oahu, and Hawaii. Egg density was fairly low, with egg distribution affected both by plant species and plant habitat. Approximately 40% of S. rufofascia eggs, averaged over all plants and sites, were parasitized by Chaetomymar sp. nr. bagichi Narayanan, Subba Rao, & Kaur; Schizophragma bicolor (Dozier); and Polynema sp. Haliday (Hymenoptera: Mymaridae). Percentage parasitism varied widely among different plant species and habitats. C. sp. nr. bagichi was the most abundant and widely distributed species, but the parasitoid guild varied depending on plant and on habitat. The implications of these results on decisions regarding classical biological control of twospotted leafhopper in Hawaii are discussed.

Frequencies are reported for restriction fragment-length polymorphisms (RFLPs) at a highly polymorphic nuclear locus in Old and New World honey bee populations. The distribution of these (RFLPs) alleles (composed of MspI and DdeI variants) had been found previously to be discontinuous among groups of Old World honey bee subspecies, which included A. mellifera mellifera L. (west European), A. m. ligustica Spinola, A. m. caucasica Gorbachev (east European), and A. m. scutellata Lepeletier (African). In this study, ancestry in New World bees was inferred from allele identities and frequencies at this locus in combination with mitochondrial DNA types. In bees from the United States, collected before the invasion of African bees, east and west European alleles were found at frequencies of 83 and 17%, respectively, which is consistent with previously identified nuclear and mitochondrial DNA markers. Colonies from two neotropical countries, Mexico and Honduras, had African mitochondrial DNA and high frequencies of African nuclear DNA alleles. Consistent with previous findings, east European alleles were absent or detected at low frequencies in these colonies. However, west European alleles were found at frequencies from 26 to 31%. These results suggest that queen offspring of the African queens first introduced into Brazil mated with west European drones, incorporating neutral markers that have since remained in the expanding population of feral African bees. The results point to little paternal introgression from managed east European colonies encountered by the African bees spreading through the neotropics.

Fully grown larvae of Prodoxus y-inversus (Riley) undergo diapause in hardened cysts in the sterile tissue of Yucca baccata Torrey fruits. Dormancy normally lasts from early summer until the following May, but when optimal climatic cues, particularly winter chilling, are not received, the diapause is maintained. Larvae of the 1969 generation were collected in April 1970 in southern Nevada and held in winter conditions that varied but were warmer than those to which the population was adapted in Nevada. More than 180 individuals emerged synchronously following the 16th and 17th winters. Temperature data suggested that the intensity of winter chilling is the primary factor initiating diapause development and that after many years in diapause larvae are conditioned to respond to temperature regimes that were not acceptable for development in the early years of diapause. To test these hypotheses, larvae were held in constant warm temperatures for 4–5 yr, then exposed to a variety of winter conditions. Additional large groups eclosed following their 20th (151 adults) and 25th (125 adults) winters. X-rays before the 30th winter indicated that few larvae remained, and 14 moths emerged following 30 yr in diapause.

Larvae of Tiphodytes gerriphagus Marchal, a parasitoid of water strider eggs, are able to develop within Limnoporus dissortis Drake & Harris eggs that have undergone >80% of their embryological development. In laboratory studies, parasitoid development time was unaffected when young and intermediate aged eggs were attacked, but increased when old host eggs (6 to 8 d) were used. Likewise, wasp body size did not change significantly except for the oldest host eggs, from which significantly smaller wasps emerged. Old egg batches produced higher sex ratios (more males) than young eggs. This resulted from a disproportionate reduction in female eggs laid in the context of a marked overall reduction in parasitoid oviposition. Ability to parasitize over a wide range of host ages likely contributes to the high rates of parasitism observed in the field.

The beetle Melanophila acuminata (De Geer) is able to detect infrared radiation emitted from forest fires with two infrared receptors (pit organs) located on the metathorax next to the coxal cavity of the second set of thoracic legs. Each pit organ houses ≈70 single IR sensilla, which probably transduce incoming IR radiation into a mechanical event. These pit organs may exhibit chemical differences from the cuticle covering other parts of the beetle, which could account for their enhanced infrared detection. Infrared pit organs and the elytra, the cuticle covering the wings, were subjected to LC/MS analysis by extracting the cuticle with solvents that varied in polarity. The resulting chromatograms and mass spectra were used to identify differences in solute mobility and composition. Energy dispersive spectroscopy and point dwell maps indicated only the presence of carbon, oxygen and nitrogen for the pit organs, wings and elytra. FT-IR transmission spectra were obtained for the pit organs, eye scales, coxal cavities and wings. FT-IR analysis detected chemical bonding for the sensilla of the pit organ, which agreed with the energy dispersive spectroscopy results. Sensilla absorb IR radiation at the maximum emission wavelength of forest fires, and there is no indication of a complex chemical reaction occurring upon IR absorption. Therefore, the degree of expansion of the cuticular apparatus of the IR sensilla seems to be the sole contributing factor for the photomechanical portion of infrared detection.

A method for cryopreserving embryos of the screwworm, Cochliomyia hominivorax (Coquerel), was developed for the long-term storage of strains used in research projects and for colonies maintained as back-up to production strains that are mass-reared for sterile insect release programs. This protocol, when combined with a previous procedure that was designed to render screwworm embryos permeable to water loss and the influx of cryoprotectants, yields rates of ≈53% hatching, 22% pupation, and 75% adult emergence. These yields are all lower than control levels, but by the next generation the progeny of the cryopreserved flies are near or equal to control levels and are available in sufficient numbers to reestablish laboratory colonies. Important to the success of this study was identifying the optimum embryonic stage for treatment, formulating an incubation regime, which allowed consistent retrieval of embryos at the optimum stage, establishing the correct dehydration time for the previtrification step, and developing a recovery system after liquid nitrogen storage of the embryos.

A chemically defined diet (Ceratitis capitata #2 diet) for rearing adult Ceratitis capitata (Wiedemann), the Mediterranean fruit fly, was developed by adding vitamin B₁₂ 0.024 mg, ascorbic acid phosphate (vitamin C) 3.68 mg, vitamin D 12 mg, vitamin E 8.16 mg, inositol 243 mg, choline chloride 120 mg, cholesterol 40 mg, nicotinic acid 1.64 mg, sugar 6 g, agar 400 mg, and water 7 ml to each 50 g meridic larval diet (C. capitata #1). The C. capitata #2 diet was prepared in two forms, agar and liquid and both showed comparable performance to the standard diet but the agar diet is considered to be the best diet tested. Adults reared on the agar diet produced more eggs than those on a protein hydrolysate-sugar (1:3) diet. Flies fed on diets lacking nutrient groups, such as the 10 essential amino acids, eight nonessential amino acids or the combination of cholesterol, inositol, and choline, produced fewer eggs. Those fed on the diet without the 14 vitamins, cholesterol, inositol, or choline produced a normal number of eggs. Increasing the sugar content in the diet did not affect egg production or hatch. Sugar concentration in the diet influenced fly survival.

Cuticular hydrocarbons from the ponerine ant Ectatomma ruidum Roger and a highly integrated eucharitid myrmecophile, Kapala sulcifacies (Cameron), associated with it, have been characterized. Ninety hydrocarbons were identified from the ant, 55 hydrocarbons from the female wasp and 54 hydrocarbons from the male wasp. The wasps and ants share 40 hydrocarbons. These shared 40 hydrocarbons represent 92.6% of their hydrocarbon composition for female Kapala, 84.3% for male Kapala and 67.7% for the ants. The wasps have a carbon number range of C₂₇ to C₃₅; the ants have a range of C₂₃ to C₃₅. Both species possess n-alkanes, C₂₇ to C₃₃ for the wasps, C₂₃ to C₃₄ for the ants. Both species also possess major quantities of Z-7- and Z-9 alkenes: C₂₉ to C₃₃ for the wasps; C₂₃ to C₃₅ for the ants. The female wasps possess a low amount of a conjugated C₃₁ diene (neither the ants nor the male wasps possess this hydrocarbon), and the ants, but not the wasps, contain low quantities of nonconjugated dienes (carbon numbers of C₂₃ to C₂₉) with double bonds at Δ⁹, and Δ¹⁴. Both wasps and ants share homologous series of 3-, 5-, 10-, 11-, 12-, 13-, 15- and 17-methyl branched alkanes. Ants and wasps also share a homologous series of 3,7-dimethyl alkanes. Other internally branched dimethyl alkanes are found in both ants and wasps, but only 11, 15-DiMeC₂₉ is shared. Wasps have 7, 15- and 10, 14-dimethyl alkanes while the ants have 15,19-dimethyl alkanes. Kapala sulcifacies and E. ruidum both possess hydrocarbons of the 5, X-, 11, X-, 12, X- and 13, X-DiMe series, but the compounds involved are not shared because they represent different compounds. Behavioral observations indicate that the ants accept the newly emerged adult parasitoids with no evidence of agonistic behavior for a period of time after adult eclosion. Nevertheless, the chemical deception is not completely efficient because young adult Kapala are soon ejected from the nest by transportation by their host. These transportations frequently occur after seizure at the base of the wasps’ characteristic scutellar spines, such structures allowing for easy transportation without injury for the parasite. Moreover, if no method of escaping the colony is provided, the ants ultimately attack the parasitoids. The substantial chemical overlap of the cuticular hydrocarbon profiles of the ants and wasps are discussed in the context of the social life of the colony.

We report experimental interspecific hybridization between Anastrepha fraterculus (Wiedemann), A. sororcula Zucchi, and A. obliqua (Macquart), widespread and highly destructive crop pests in the Neotropical region. Prezygotic reproductive isolating mechanisms (such as different mating times and male calling songs) seem to be easily disrupted in no-choice crossing conditions, and hybrid flies can be obtained in both directions in most crosses. Crosses between A. sororcula females and A. fraterculus males and between A. obliqua females and A. sororcula males yield adult offspring of males and females. Crosses between A. fraterculus or A. sororcula females and A. obliqua males yield only females, clearly obeying Haldane’s rule (preferential inviability or sterility of heterogametic hybrids). Crosses between A. obliqua females and A. fraterculus males and between A. fraterculus females and A. sororcula males yield poor or no adult offspring of both sexes, with a few exceptions. Most F₁ hybrids are fertile and can be backcrossed to both parental species. The few morphological diagnostic characters of the parental forms appear intermediate in F₁ hybrids. In addition, we describe some morphological abnormalities found in hybrids, attributed to maternal or cytoplasmic effects, and the occurrence of gynandromorphs in the progeny of one cross.

Ribosomal ITS1 DNA sequences have been characterized in Ceratitis capitata (Weidemann), the Mediterranean fruit fly, and Ceratitis rosa (Karsch), the Natal fruit fly. In C. capitata the ITS1 region is 831 bp in size (on average). Relatively little variation in the makeup of the ITS1 DNA sequences was detected in individuals sampled from numerous worldwide populations of C. capitata. In C. rosa, however, a substantial difference in the size of the ITS1 region was observed in individuals from a collection made in Kenya compared with individuals from South Africa. In the C. rosa flies from South Africa, this region was ≈930 bp in size, compared with a size of 717 bp in the C. rosa Kenya flies. This difference appears to be due primarily to a single insertion or deletion event. Using polymerase chain reaction, these size polymorphisms are easily detectable and can be used for making species identification and/or population origin determinations using material from any stage of the life cycle. Despite these intra and interspecific differences, sequences from the ITS1 regions of both C. rosa collections and C. capitata can still be aligned. Quantification of the similarity of these sequences may help to resolve continuing questions over the status of species relationships in this genus.

Members of the genus Cryptocercus are subsocial, xylophagous cockroaches that inhabit temperate forests of the Nearctic and Palaearctic. Seven species are recognized worldwide: five in the United States, and one each in Russia and China. Four (Cryptocercus darwini Burnside, Smith and Kambhampati, Cryptocercus garciai Burnside, Smith and Kambhampati, Cryptocercus punctulatus Scudder, Cryptocercus wrighti Burnside, Smith and Kambhampati) of the five species in the United States occur in the Appalachian Mountains and one (Cryptocercus clevelandi Byers) occurs in the Pacific Northwest. Previous studies have indicated that the distribution of the Appalachian species is allopatric; however, three of the four species occurred within a few kilometers of one another. Therefore, an intensive survey was undertaken in southwestern North Carolina and northern Georgia to determine if the species distributions are indeed allopatric or if there are zones of sympatry. With regard to C. clevelandi, previous studies have included samples from only a handful of locations in the western United States. Therefore, an extensive survey was undertaken in Oregon and California to map the geographic distribution of C. clevelandi and estimate genetic variation within and among populations. Our surveys indicated that three (C. darwini, C. garciai, C. wrighti) of the four Appalachian species have overlapping distributions in southwestern North Carolina and northern Georgia, a finding that raises the possibility of the existence of hybrid zones. Genetic variation among samples collected in Oregon and California indicated that, unlike the eastern United States, there is only one species of Cryptocercus in the western United States. In addition, we found that the distribution of C. clevelandi is considerably more patchy than that of the Appalachian species.

The relationships between leaf trichome densities, leaf age, and sweetpotato whitefly, Bemisia tabaci (Gennadius) biotype B, infestations of 13 upland cotton, Gossypium hirsutum L., cultivars were investigated in 1990 and 2000. Stoneville 474 supported higher numbers of B. tabaci biotype B eggs, nymphs and adults, and also had higher numbers of stellate trichomes on abaxial leaf surfaces compared with other cotton cultivars. Siokra L-23, in general, had fewer stellate trichomes and also fewer whiteflies. However, the positive trichome–whitefly density relationships were affected by the ages of leaves from different main stem cotton nodes. The youngest leaves on main stem node 1 below the terminal for all cultivars had higher numbers of stellate trichomes but fewer whiteflies compared with older leaves.

Copulation duration and daily reproductive activity pattern of the stink bug Megacopta punctatissima Montandon were investigated in the laboratory and the field. Mean copulation duration was >10 h regardless of sex ratio and few copulations continued for more than 24 h in the laboratory. In the field, mating aggregations and copulations were found from 1400 to 1000 hours on the next day, but bugs tended not to copulate from 1000 to 1400 hours. This daily reproductive activity pattern seemed to restrict the copulation duration to about 24 h at the longest. Sperm transfer from a male to a female spermatheca was complete within 2–4 h. Thus, it appears that copulations over 4 h serve as postcopulatory mate guarding. However, copulations did not always continue until oviposition because female oviposited after about a 7-d interval. Our findings suggest the possibility that prolonged copulations that do not continue until oviposition may also function as postcopulatory mate guarding within daily reproductive time. Alternative hypotheses, such as copulatory courship, for prolonged copulation of M. punctatissisma are also discussed.

The sexual behaviors of Okanagana canadensis (Provancher) and O. rimosa (Say) are described. In northern Michigan, O. canadensis is typically found in coniferous vegetation, such as cedars; whereas O. rimosa frequent deciduous vegetation. In both species, males call from stationary perches, and females approach them. Females have no specialized receptivity signals, but both males and females engage in bouts of wing flicking that may be alternative, low-risk signaling. Mating is brief and involves no elaborate courtship. The Okanagana mating system, characterized by male advertisement and female searching, is contrasted with that of Magicicada spp., the periodical cicadas of North America, and discussed in the context of relative risks of signaling and searching behaviors.

Silverleaf whitefly, Bemisia argentifolii Bellows & Perring, adults and nymphs feed on the phloem tissue of host plant leaves. Infested leaves were rapidly fixed to prevent the insects from withdrawing their mouthparts. The adult stylet bundle enters the labial groove of the labium between the first and second segments and is completely contained within the labium except during feeding. Stylet length is equal to the combined length of labial segments 2, 3, and 4. Stylet penetration can be determined by examining the position that the stylet enters the labial groove. The physical force necessary for adult stylet penetration is derived from changes in the position of the whitefly head during feeding. The head is bent over the labium, which is attached to the leaf surface, forcing the stylet bundle down the labial groove and into the host tissue. Nymphal stylet lengths were found to be longer than previously reported, and of sufficient length to reach the phloem tissue in cotton and hibiscus leaves from essentially any position on the abaxial leaf surface.