Intensive predepositional bone modification is described from fossil vertebrate remains. The bone material is derived from terrestrial Pliocene deposits exposed in the Laetoli area (Northern Tanzania), which represents predominantly vulcanoclastic material. The modifications described are shallow grooves with a U-shaped profile, as seen using scanning electron microscopy. The grooves form clusters of radially arranged grooves with 3–8 mm diameter that randomly cover bone surfaces forming broad surface erosion and lining subcortical cavities in the compact bone. Because of the paired arrangement of isolated grooves constituting the clusters, the modifications are attributed to yet unknown insects. Termites are tentatively suggested as possible producers of the marks.

A new Scolebythidae Eobythus patriciae gen. nov., sp. nov. is described from the Lowermost Eocene amber of the Oise Valley (France). A first attempt at a phylogenetic analysis suggests that the fossil genera Eobythus gen. nov. and Libanobythus Prentice et al. (1996) would constitute an original clade not directly related to the three modern scolebythid genera.

Eutarsopolipus (Tarsopolipus) lagenaeformis (Berlese, 1911), type species for the genus Eutarsopolipus Berlese, 1913, is redescribed based on detailed observations of recently collected specimens from near the type locality in Italy and specimens from Algeria. Type specimens of E. lagenaeformis in the Berlese Collection, Florence, Italy, were reviewed by R.W.H.

The genus Horstiella is revised; one nominal species (H. armata Turk) and six new species, H. concentrica, H. megamyzidos, H. mourei, H. quadrata, H. snellingi, and H. variabilis, are described and illustrated. The species are associated with 14 species of bees of the genus Epicharis from the Neotropical region, ranging from central Mexico through Brazil. Mite species are not restricted to single bee species, and two mite species may occur on the same host individual. The genera Horstia and Medeus are hypothesized to form the sister group of Horstiella. Phylogenetic analysis produced a single cladogram resolved at the species level. H. mourei and the species pairs H. armat –quadrata, H. concentrica–megamyzidos, and H. snellingi–variabilis are each associated with species in one or two subgenera of Epicharis. A key to the species of Horstiella is provided. RESUMEN El género Horstiella es revisado; seis nuevas especies: H. concentrica, H. megamyzidos, H. mourei, H. quadrata, H. snellingi, H. variabilis y la especie tipo (H. armata Turk), son descritas e ilustradas. Estas especies de ácaros están asociadas con 14 especies de abejas del género Epicharis en la región neotropical. El género Horstiella se localiza desde la región central de México hasta Brasil. Los ácaros no están restringidos a una sola especie de abeja y más de una especie de Horstiella puede ser encontrada en una especie de Epicharis. Los géneros Horstia y Medeus son hipotetizados como un grupo hermano del género Horstiella. El análisis produjo un único cladograma resuelto a nivel de especie. H. mourei y las especies pares H. armata–quadrata, H. concentrica–megamyzidos, y H. snellingi–variabilis están asociadas con especies en uno o dos subgeneros de Epicharis. Notas sobre las características de campo, interrelaciones con sus hospederos, y una clave para las especies descritas dentro del género Horstiella son incluidas.

Reciprocal molecular markers were developed to distinguish the closely related parasitoid species Encarsia formosa Gahan and E. luteola Howard. E. formosa is widely used in the biological control of whiteflies and yet, based upon morphology, it is extremely difficult to distinguish from E. luteola. The D2 expansion region of 28S rDNA was sequenced from seven strains of E. formosa and two strains of E. luteola to assess the amount of genetic variation within and between species at this locus. From parsimony analysis we find that populations of E. formosa and E. luteola each form a monophyletic clade and are probably each other’s most closely related sister taxon. Based upon the sequence variation between species, we present a simple molecular assay to rapidly and unambiguously distinguish E. formosa and E. luteola.

Phylogenetic relationships of mosquitoes in the subfamily Anophelinae are presented based on a cladistic analysis of 163 morphological characters from females, males, fourth-instar larvae, and pupae of 64 species. Species examined include one Chagasia Cruz, three Bironella Theobald, and 60 species representing all six subgenera of Anopheles Meigen. Uranotaenia lowii Theobald and Aedeomyia squamipennis (Lynch Arribalzaga) are used as outgroups. This analysis indicates that Anophelinae is monophyletic, that Chagasia is the earliest-diverged lineage within Anophelinae, and that the genus Anopheles, as currently defined, is paraphyletic because it excludes Bironella. Four nonhomoplastic synapomorphies support the monophyly of the clade composed of the genera Bironella and Anopheles. Three major lineages are recognized within this clade. The basal lineage (lineage 1) contains An. (Nyssorhynchus), An. (Kerteszia), and An. implexus (Theobald). This analysis supports the monophyly of the sister groups Nyssorhynchus Blanchard and Kerteszia Theobald, but finds the Albimanus, Argyritarsis, and Myzorhynchella sections of the subgenus Nyssorhynchus to be paraphyletic. The second lineage (lineage 2) contains species of the subgenus Cellia Theobald, which is monophyletic. Except for the Cellia series, however, all other series of the subgenus Cellia are paraphyletic. The third lineage (lineage 3) contains species of the subgenera Anopheles Meigen, Stethomyia Theobald, Lophopodomyia Antunes, and of the genus Bironella. Bironella and Stethomyia are monophyletic sister groups. The Lophoscelomyia and Arribalzagia series are monophyletic. The Arribalzagia and Cycloleppteron series are sister groups nested within the Myzorhynchus series. We conclude that there is no support for the generic recognition of Bironella, nor the subgeneric rank of Lophopodomyia and Stethomyia.

Larval and adult stages of a new species of Chrysopa, C. timberlakei Penny, Tauber & de Leon, from the mountains of eastern California (elevation 1,370–2,200 m) are described. Biological data are given and a key is presented for the adults of the 10 recognized species of North American Chrysopa.

Two species of dampwood termites, Neotermes jouteli (Banks) and N. luykxi Nickle & Collins, are redescribed based on the imago and the small and large soldier caste. Morphological characters are reported to separate the above castes of these two species. N. jouteli occurs in southeastern Florida, the central Bahamas, Cuba, and Mexico. N. luykxi is endemic to southeastern Florida, the Bahamas, and Turks and Caicos Islands, but is apparently absent from Cuba. A key to the Neotermes found sympatrically with N. luykxi is given.

The larvae of Euphoria devulsa Horn and Euphoria lurida (F.) (Coleoptera: Scarabaeidae: Cetoniinae: Cetoniini: Euphoriina) are described for the first time. The larval biology of these species and others in the genus is reviewed. A key to the 7 known species of Euphoria larvae is provided.

RESUMEN Se describe por primera vez la larva de Euphoria devulsa Horn y de Euphoria lurida (F.) (Coleoptera: Scarabaeidae: Cetoniinae: Cetoniini: Euphoriina). Se aportan datos sobre la biología larvaria de dichas especies y de otras especies del género. Se proporciona una clave de identificación para las larvas de especies de Euphoria hasta ahora conocidas.

Stirotarsinae, new subfamily, is erected for the monotypic genus Stirotarsus Bergroth. Diagnoses for the subfamily and the genus, Stirotarsus, as well as a detailed description for the species Stirotarsus abnormis Bergroth are provided. The phylogenetic position of Stirotarsinae is discussed. Peru is reported as a new locality record for this species.

The genetic structure of 41 Canadian populations (27 populations from British Columbia, two of which were from east of the Continental Divide, and the remaining 14 representing localities east of the Continental Divide) of the white pine weevil, Pissodes strobi (Peck), was investigated using isozyme markers. Differentiation among populations (F_ST) was estimated to be 0.084 and inbreeding within populations was low with estimated mean F_IS of 0.011. Although overall genetic uniformity among the studied 41 populations was high (mean Nei’s genetic distance = 0.027), differences among groups of populations were revealed in cluster analyses. The 16 weevil populations obtained from areas east of the Continental Divide formed a significant cluster with the 11 populations collected from the Interior British Columbia. The 11 weevil populations examined from the South Coast–Vancouver Island of British Columbia were distinct from this cluster, as were the three weevil populations collected from the North–Central Coast of British Columbia. Populations within the South Coast–Vancouver Island group were the most genetically dissimiliar to each other, with Nei’s genetic distance ranging from 0.004 to 0.108. This was caused, in part, by differences in allele frequencies in the Bella Coola, Eve River, and Nanaimo populations relative to the other eight populations within this group. Genetic diversity estimates, in terms of the mean number of alleles per locus, the percentage of polymorphic loci and the mean expected and observed heterozygosity, were higher in eastern than western populations.

Field sex ratios of the solitary ectoparasitoid wasp Heterospilus prosopidis Viereck were examined. H. prosopidis mates panmictically in the field, and the size of their bruchid hosts vary. According to the theory that combines local mate competition and host quality effects, two major predictions for H. prosopidis sex ratios in the field can be made: more females should emerge from larger hosts, and 1:1 or slightly male-biased sex ratios should be observed in a natural population. Prosopis seeds infested with bruchids were collected in Hawaii, Arizona, and Texas in 1996, 1997, and 1998. Among nine collections, six did not deviate significantly from a 1:1 sex ratio, one showed a male-biased sex ratio, and two were female-biased. Although environmental factors other than host quality and mating structure may influence sex ratio temporally or spatially, these results generally support our predictions.

A review of the entomological literature revealed relatively few general studies on arthropods in urban environments, excluding those in the context of pest control or epidemiology, and all were limited in scope and duration. Most studies documented the presence and abundance of species in a variety of poorly quantified urban categories. There also were a number of studies on the effects of urban pollution and changes in arthropod community composition over time (particularly in urban green areas). From these studies, three groups of arthropods could be identified: (1) “rural” taxa not present (or at lower abundance) in urban settings, (2) “urban” taxa present only (or at higher abundance) in urban settings, and (3) taxa present in both rural and urban settings with no particular affinity for either. The lack of a basic understanding of the mechanisms accounting for distributional and abundance patterns of urban arthropods illustrates the many opportunities for entomological research that exist in urban settings. Some of these opportunities are outlined to encourage further work on the ecology of urban arthropods.

In burying beetles (Nicrophorus), male and female pairs bury small carcasses to supply their larvae with food. Both parents care for their larvae for several days and defend them against other burying beetles that try to usurp the carcass. Male defense is very effective in preventing take-overs by conspecifics, but ineffective against attacks by larger congeners. From information on four species of Nicrophorus, Scott (1998) suggested that this asymmetry affects the duration of male care; males care longer when the major competitors are conspecifics, and leave early if they are larger congeners. We performed a field study examining the phenology of N. investigator Zetterstedt and its sympatric congeners in Bielefeld, Germany. Because of its relatively low abundance, an N. investigator arriving at a carcass had a much higher chance to meet an individual of another species of burying beetle than to meet a conspecific, suggesting that intraspecific competition is less important than competition by congeners. Breeding experiments showed that male care in N. investigator was shorter than in the numerically dominant species N. vespilloides Herbst and N. vespillo (L.), supporting Scott’s hypothesis. However, we cannot exclude that the differences in male care were caused by other factors that vary between species, as for example the speed of larval development. Also, the probability of encounter used to estimate the relative importance of intra- and interspecific conflicts only gives a rough estimate of the competitive situation because of differences in fighting ability between species.

I conducted a series of laboratory experiments to quantify the effects and elucidate the mechanisms by which Pseudacteon tricuspis Borgmeier phorid flies affect the exploitative and interference components of interspecific competition in host Solenopsis invicta Buren ants. In manipulative experiments, workers retrieved 50% less food in a foraging tray with phorids present, compared with an equidistant foraging tray with the same food resource but without phorids. The average number of workers actively foraging in the tray with phorids was significantly less than in the tray without phorids. There were no significant differences in either average worker size or average number of workers present at the food resource at the end of the trials in trays with phorids versus trays without phorids. In a control set of trials in which no phorids were added to either foraging tray, the size of foraging workers averaged over both foraging trays was significantly larger than in either the phorid or no-phorid tray of the manipulative experiments. This suggests that colonies can communicate the generalized presence of phorids in an area, which leads to a decrease in foraging by major workers. S. invicta workers retrieved an intermediate amount of food in the foraging trays of the control experiment compared with the phorid and no-phorid trays of the manipulative experiment. Moreover, the overall amount of food obtained in both foraging trays was similar for the manipulative and control experiments, suggesting that the S. invicta colonies were able to compensate for harassment by phorids by altering their foraging strategy, which resulted in no net loss of food retrieved. When S. invicta was paired with S. geminata (F.) in interference competition experiments, phorid flies had no effect on the outcome of interspecific interactions. Phorids did not appear to be attracted to host workers once they were engaged in combat with enemy workers, and the spatial distribution of fighting was significantly different than the spatial distribution of parasitization attempts.

Life history, survivorship, and adaptation of the bandedwinged whitefly, Trialeurodes abutiloneus (Haldeman), on sweet potato, Ipomoea batatas (L.) Lam, and two species of Hibiscus were studied in laboratory and screen houses. T. abutiloneus deposited significantly more eggs on cotton rose, Hibiscus mutabilis L. (10.3–11.3 eggs per female), and roselle, Hibiscus sabdariffa L. (10.1–11.8 eggs per female), than on sweet potato (6.1–7.3 eggs per female) in a choice test when the whiteflies were previously reared on cotton rose and roselle. Whereas, whiteflies originally reared on sweet potato deposited more eggs on sweet potato (10.4) than on cotton rose (7.3) and roselle (6.1). However, differences in oviposition among these three host plants were not significant in a no-choice test, regardless of their original host plants. Overall developmental times of T. abutiloneus were significantly longer on sweet potato (22.3–23.2 d) than on cotton rose (17.0–17.8 d) and roselle (17.1–17.4 d) independent of their original host plants. Survival rate of T. abutiloneus was only 12.3–21.4% on sweet potato compared with 71.5–87.2% on cotton rose and 77.7–90.3% on roselle. Linear regression analysis of the survival rates of all nymphal stages of T. abutiloneus on sweet potato after seven consecutive generations indicated that the survival rates increased (r² = 0.7419–0.8483), albeit the rates were slow. Thus, sweet potato proved to be a relatively poor host plant as well as a relatively nonpreferred one for T. abutiloneus compared with cotton rose and roselle.

Research was conducted on the production potential of selected medicinal herbal plant species as new crops suitable for cultivation in South Carolina. Whiteflies (Bemisia argentifolii Bellows & Perring) were found in an experimental production field infesting five perennial species of medicinal herbal plants [feverfew, Tanacetum parthenium (L.) Schultz-Bipontinus; St. John’s wort, Hypericum perforatum L.; purple coneflower, Echinacea pallida (Nuttall) Nuttall and E. purpurea (L.) Moench; and common valerian, Valeriana officinalis L.]. This article reports on whiteflies attacking and developing on these plant species. Density of whitefly nymphs was highest (mean = 2.3/cm²) on the second fully expanded leaf on the apical meristem of E. purpurea as compared with the same leaf position on the other plant species where average whitefly density ranged from 0.1 to 0.6 nymphs per square centimeter from late November 1998 through January 1999. Similarly, adult capture on sticky cards was high (mean = 123 whiteflies per card) in plots of E. purpurea compared with plots of the other four species (mean = 8 to 20 whiteflies per card per species), and adult counts were elevated in the highest (440 kg N/ha) of three fertility rates in E. purpurea. Moreover, laboratory tests agreed with the observation of a higher population of B. argentifolii on E. purpurea compared with the other four plant species. The whitefly completed development on all five plant species, and whitefly-associated parasitoids emerged from field-leaf samples of each plant species.

A general description of the life stages and population parameters of Catolaccus hunteri Crawford, a primary ectoparasitoid of pepper weevil, Anthonomus eugenii Cano, and boll weevil, Anthonomus grandis grandis Boheman, is presented. The parasitoids were reared on the unnatural host Callosobruchus maculatus F. The developmental time of C. hunteri at 27 ± 1°C was shorter in males than females. Males completed development in 11.46 ± 0.46 d from egg to adult emergence. Developmental time in females required 13.18 ± 0.81 d from egg to adult at the same temperature. A C. hunteri female (n = 20) laid 466.35 ± 280.39 eggs, of which just 18.35% reached the adult stage; this could be the result of cannibalistic larval behavior combined with high superparasitism observed under laboratory conditions. Female mean longevity was 47.20 ± 12.76 d. The net reproductive rate (Ro), the generation time (G), and the daily intrinsic rate of increase (rm) were 42.713, 33.842, and 0.111, respectively. The fecundity of pepper weevil and boll weevil is discussed.

Colony composition and behavior of ergatoid queens were investigated in two species of the Leptogenys diminuta group (L. diminuta Smith F. and L. sp. 12) in Indonesia. Average number of workers in queenright colonies was 277 ± 116 and 422 ± 176 in L. diminuta and Leptogenys sp.12, respectively. Most colonies had one physogastric mated ergatoid queen. All but one colony had many virgin-ergatoid queens, which represented 1.8–14.3% of females in the colonies. The virgin-ergatoid queens performed worker-like behavior when they became older. The occurrence of many ergatoid queens has rarely been observed in ponerine species. The significance of ergatoid queen production in these species is discussed.

The temperature-dependent development, survivorship, and reproduction of the spirea aphid, Aphis spiraecola Patch, on Polyscias crispata (Bull) Merr were evaluated at eight constant temperatures (10, 15, 20, 25, 28, 30, 32, and 35°C). The population failed to survive at 35°C. Between 10–32°C, developmental periods of immature stages varied from 23.0 d at 10°C to 7.3 d at 28°C. The developmental thresholds were estimated at 2.3°C for overall immature stages and 5.0, 1.4, 1.0, and 1.3°C for first to fourth stadia, respectively. The percentage of survivorship of immature stages ranged from 78.2 to 95.0% within the range of 10–30°C. However, survivorship was reduced to 29.6% at 32°C. The average longevity of adult females ranged from 36.5 d at 10°C to 6.0 d at 32°C. The average progeny per female was 44.0 at 20°C to 5.1 at 32°C. The largest r_m (0.308) occurred at 25°C. Populations reared at 32 and 10°C had the smallest r_m value of 0.040 and 0.078, respectively. The mean generation time of the population ranged from 35.1 d at 10°C to 10.7 d at 32°C. The optimal range of temperature for A. spiraecola population growth was 20–30°C. Several mathematical functions were used to quantify spirea aphid development, survivorship, reproduction, and life table parameters in relation to temperatures.

The survival of Musca domestica L. embryos was assessed after storage at 5°C. Chilling tolerance was influenced by the length of the storage period and by the age of the embryo at the time of low temperature exposure. Embryos placed into cold storage at 3 h of age were able to survive 3 d with little reduction in larval emergence or adult eclosion and vitality. One-hour-old embryos were the least tolerant of chilling and could not survive 1 d at 5°C. Three patterns of chilling injury were expressed. They are characterized as immediate, accumulative, and latent. Expression of immediate and accumulative injury was linked to the age of the embryo at the time of chilling, and the latent type of injury was expressed during the postembryonic stages of development and was related to length of cold exposure. Exposure of the house fly embryos to hypoxic conditions did not increase chilling tolerance, and a hyperoxic environment was detrimental to the use of cold storage as a strategy to increase insect shelf life.

Prepupae of Hypera eximia (LeConte) (Coleoptera: Curculionidae), a natural host, and prepupae of factitious insect hosts were tested for their physiological responses to stinging by the gregarious ectoparasite, Necremnus breviramulus Gahan (Hymenoptera: Eulophidae), and to injection with an extract of the venom gland tissue dissected from the lower reproductive tract of the female parasite. The arrestment of development produced by N. breviramulus venom was expressed in the natural host, H. eximia, and in all insects tested outside the natural host range of the parasite (Coleoptera: Curculionidae, Cerambycidae, and Chrysomelidae; Lepidoptera: Plutellidae and Noctuidae). Arrestment activity was found to be associated with the aqueous extract of the venom apparatus, and the response was shown to be dose-dependent. The protein composition of the venom from N. breviramulus differed from other eulophids tested and did not contain the molt-arresting protein found in Euplectrus spp. The difference in venom proteins may account for the different physiological effects and host range of these eulophid parasites.

Effects of growth factors on Ceratitis capitata (Wiedemann) larval development were investigated using C. capitata #1 diet as a control diet. C. capitata #1 diet is a chemical base diet with only one nonchemical bulking agent, corncob. It contains 10 exogenous vitamins in addition to those trace amounts already present in corncob, and it is capable of supporting normal larval development. Removal of all 10 growth factors from C. capitata #1 diet resulted in a prolonged developmental period, decreased pupal recovery, pupal weight, and adult emergence, but normal flight ability and egg hatch. C. capitata #1 diet lacking exogenous nicotinic acid resulted in complete second-instar mortality. In the absence of exogenous riboflavin, larvae reached the third instar and pupated, but the rate of development was slower. However, the percent pupal recovery was not significantly different. Pupal weight and adult emergence were significantly decreased, whereas flight ability and egg hatch remained within normal ranges. The effects of omitting exogenous pantothenic acid were similar to those for riboflavin compared with the control diet. The omission of other exogenous vitamins, such as thiamine, pyridoxine, biotin, folic acid, ρ-amino benzoic acid, inositol or choline, had no significant effects on the rate of larval development and survival. Exogenous nicotinic acid was determined to be indispensable (requires a minimum of 2 ppm), whereas riboflavin and pantothenic acid appear to be required (at least >2 ppm) for normal growth and development of C. capitata larvae. Addition of exogenous ascorbic acid phosphate or α-tocopherol in C. capitata #1 diet did not improve C. capitata development or growth. Wheat germ is not necessary as a mass rearing diet additive because two of its major nutrients (α-tocopherol and choline) showed no impact.

Megachile rotundata (F.), a gregarious, cavity-nesting, leaf-cutting bee, is used throughout North America for the pollination of alfalfa, Medicago sativa L., seed crops. We examined the influence of various temperature regimes on development, survival, emergence, and longevity in both nondiapausing and diapausing forms of this species. In general, development rates increased with increasing constant temperatures used in this study (18, 22, 26, and 29°C), but the 26 and 29°C treatments were clearly superior as rearing temperatures for immatures. In diapausing individuals, a variable temperature treatment 14:27°C (8:16 h daily cycle, mean 22°C) reduced the length of prepupal and pupal development stages following incubation in the early summer when compared with individuals reared under the constant 22°C treatment. We discuss the importance of differing temperature regimes on M. rotundata development, survival, and longevity over the entire life cycle. We also discuss the importance of making a connection between immature development and sufficient wintering conditions to postdiapause development, a topic that has received much more attention in the literature.

We compared Bemisia argentifolii Bellows & Perring colonization on Stoneville (ST) 474 and Deltapine (DPL) 5415 cottons, Gossypium hirsutum L., in the field. We also examined leaf trichome density, leaf age, and leaf morphological characteristics as possible factors influencing cultivar host selection. The increased numbers of all B. argentifolii life stages on ST 474 in the field appeared to be related to the higher trichome density on abaxial leaf surfaces compared with DPL 5415. In both cultivars, leaves from node number 1 below the terminals were smaller and had higher vascular bundle densities and numbers of lysigenous glands than older, larger leaves. Younger leaves also had smaller leaf areole areas, more terminal vein endings per unit leaf area, and shorter distances from abaxial leaf surfaces to minor vein phloem tissues compared with older leaves. These younger leaf morphological characteristics may contribute to the higher B. argentifolii densities on younger leaves. In the laboratory, electronically monitored adult females and visually monitored settled first and fourth instars preferred to probe into secondary and tertiary leaf veins as compared with main and primary leaf veins.

Members of the arctiine moth tribes Ctenuchini and Euchromiini exhibit extreme morphologies including the evolution of convincing wasp mimicry. The lepidopteran abdomen is constricted to produce the visual effect of a hymenopteran petiole (petiole mimic). Many of these species also possess an abdominal “ventral valve” that has been ascribed both a defensive and a courtship function. We examined 85 species (45 genera) to determine the structural variation and distribution of these unique morphologies. Width-length ratios of modified and unmodified segments were generated from 52 species to describe the abdominal constriction in petiole mimics and unmodified abdomen. Here, we provide the first detailed descriptions and illustrations of the morphologies of petiole mimics and ventral valves. Two independent derivations of petiole mimics occur in this clade. Similarly, not all ventral valves are homologous. We propose the phrase “subabdominal pouch” to replace “ventral valve” because it more accurately describes these morphological structures. Petiole mimics may involve modification of either sternite II (SII) or III, but only SIII petiole mimics lack subabdominal pouches. This result suggests that the presence of one morphological innovation (petiole mimic) limits the possession of the other (androconial type).

Many aphid (Aphidae) and treehopper (Membracidae) species depend on ants (Formicidae) for their survival, but few leafhopper (Cicadellidae) species have been reported as myrmecophiles. We studied the Mexican species Dalbulus quinquenotatus Delong & Nault in the field and greenhouse. In Jalisco, Mexico, field populations of D. quinquenotatus increased in size when ants were present on their gamagrass (Tripsacum species) hosts. When ants experimentally were excluded, predatory spiders invaded the gamagrass habitat and extinguished D. quinquenotatus populations. Ants also eliminated two nonmyrmecophilous and potential competitor Dalbulus species from the host-plant microhabitat of D. quinquenotatus. Greenhouse populations of D. quinquenotatus killed gamagrass hosts in the absence of predators and attendant ants. Ants (Formica subsericea Say) on gamagrass regulated captive leafhopper populations by removing nymphs and adults, and kept leaf surfaces free from contaminating honeydew. Ants also protected leafhoppers from experimentally introduced nabid predators; in the absence of ants, nabids eliminated leafhopper populations. Diet influenced the response of ants to populations of D. quinquenotatus. When ants were denied food, they preyed upon and extinguished greenhouse populations of D. quinquenotatus, but when supplied with prey (dead eastern yellowjackets), large numbers of ants attended leafhopper populations that grew in size. Few ants attended leafhoppers if they were supplied with insect prey and honey. Our data strongly suggest that D. quinquenotatus is an obligatory myrmecophile.

We report the results of an 8-yr trap nesting study on the reproductive behavior of two cleptoparasite bees, Coelioxys funeraria Smith and Coelioxys moesta Cresson. This study provided a unique opportunity to examine parasite-host adaptation within a species, in which two different size classes of C. funeraria consistently laid eggs in the nests of the two different sized Megachile hosts, M. relativa Cresson and M. inermis Provancher. Additionally, we compared the behavior of C. funeraria to another Coelioxys, C. moesta, which also parasitized the nests of M. relativa. One striking pattern we found was the tight concordance of emergence times between hosts and parasites. The emergence patterns of individual C. funeraria parasitizing M. relativa nests closely matched that of the host, as well as that of C. moesta, which parasitizes the same host. These emergence patterns were significantly different from those of C. funeraria on M. inermis. We also found that Coelioxys and Megachile apportioned male and female offspring in the same parts of the linear nests and at similar times of the season. Female offspring tended to be placed in the innermost cells early in the season and males in outer cells later in the season. Because emergence patterns can severely affect offspring survival in these linear nesting situations, we suggest that the emergence times of males and females have determined the patterns of sex placement in both host and parasites.

The sterile insect technique is gaining an increasing role in the control of Mediterranean fruit fly, Ceratitis capitata (Wiedemann), populations. In the current study, we examine how post-teneral nutrition during the first 4–8 d after adult emergence affects performance and copulatory success in leks of mass-reared sterile (TSL strain) males. We found that protein and sugar fed males were significantly more likely to emit pheromone (call) in leks, and more likely to copulate, than males fed only sugar. Sterile males, who had access to water and apples after 4 d of feeding on protein and sugar, or sugar alone, were significantly more likely to copulate than their starved competitors who had access to water alone. However, after 24 h of starvation, 4-d protein-fed males suffered a higher mortality than sugar-fed males. More work is necessary to determine the optimal protein formulation that will maintain a balance between hastened mortality and increased sexual competitiveness of sterile males.

If the primary function of ultrasound-sensitive ears in Lepidoptera is to detect the echolocation calls of insectivorous bats, diurnal species should exhibit signs of ultrasonic deafness. To test this hypothesis we recorded the 24-h (diel) flight activity of a sample of Neotropical butterflies and moths, including members of the Dioptinae, a reportedly diurnal moth subfamily. All of the butterflies examined were exclusively diurnal and we suggest that these insects are day-locked because they lack the ultrasound-sensitive ears that permit nocturnal taxa to co-exist with bats. Nondioptine moths possess sensitive, bat-tuned ears and exhibit levels of nocturnal flight ranging from complete to mixed day/night activity. Dioptine moths are significantly less nocturnal and significantly deafer than nondioptines and exhibit flight activity patterns ranging from completely diurnal to completely nocturnal. We suggest that diurnality in the Dioptinae is an apomorphic trait that has resulted in a loss of auditory sensitivity in some species but that others may retain functional ears depending on their levels of nocturnality and consequent exposure to bats.

The mystery of where virgin female Microsepsis armillata (Melander & Spuler) copulate has been solved with the discovery of sexual activity in small aggregations that are not tightly associated with the oviposition sites, where matings have been observed previously in this and other sepsid species. Nonvirgin females also mate in these aggregations, and matings at such sites may help explain the otherwise puzzling variations in male precopulatory riding behavior in other sepsids. Approximately 25% of the unpaired females in aggregations carried an unlaid egg in her bursa, and larvae had hatched from some of these eggs. Retention of a bursal egg could prevent intromission by males.

Mating behavior of the leaffooted bug Leptoglossus clypealis Heidemann was studied in the laboratory (27 ± 1°C, 60 ± 10% RH, photoperiod 16:8 [L:D] h). The mean premating period was 16.42 ± 0.42 d (mean ± SE). Males initiated courtship displays to females 8.13 ± 0.12 d after emergence. Paired adults mated 17.63 ± 2.02 times during their lifespan. The mean copulation duration was 3.85 ± 0.49 h. Copulations occurred throughout the day, but the majority (55%) took place during the 8 h scotophase. Mating behavior began with a male attracting a female from a distance, followed by the male approaching and courting the female at close range. Observations of mating behavior and bioassays indicated that the male produces a pheromone blend with both sex attractant and aphrodisiac functions. The male abdominal stretching behavior (stretching the ninth and part of the eighth abdominal segments frequently, and stroking them with the hind legs) during calling and courtship may aid in release and dispersal of male sex pheromone from the sex-specific ventral abdominal gland.