Showing papers in "Annals of The Entomological Society of America in 1993"
TL;DR: Gypsy moths, Lymantria dispar L., were accidentally introduced into the United States from Europe more than a century ago and have become a major forest pest in eastern North America.
Abstract: Gypsy moths, Lymantria dispar L., were accidentally introduced into the United States from Europe more than a century ago and have become a major forest pest in eastern North America. Recently, concern has arisen over possible establishment of gypsy moths of Asian origin in western North America. Because Asian moths have distinctive ecological and behavioral characteristics, it is essential to monitor their presence. Identification of pheromone-trapped males based on morphology is not straightforward, but comparisons of mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) and sequences reveal diagnostic differences between Asian and North American haplotypes. An mtDNA survey of moths trapped in the Pacific Northwest in 1990 and 1991 documents the presence of moths of Asian origin at several sites in North America. These results provided the basis for undertaking efforts in 1992 to eradicate gypsy moth populations of Asian origin in both the United States and Canada.
129 citations
TL;DR: Levels of genetic variation within a geographically isolated relict population (Martha's Vineyard, MA) as well as within an undisturbed population (Chesapeake Bay, MD), were very low, indicating that even historically these beetles were genetically depauperate.
Abstract: Cicindela dorsalis dorsalis Say has been listed as an endangered insect species. As part of ongoing research and restoration efforts, we investigated the levels of genetic variation in this species. The polymerase chain reaction was used to amplify and subsequently sequence 25,000 base pairs of mitochondrial DNA from 32 individuals of C. d. dorsalis and several related species and subspecies. In addition to the mtDNA data, allozyme variation in 11 clearly resolvable nuclear biochemical loci was studied and analyzed separately within populations, between populations, and between subspecies. Levels of genetic variation within a geographically isolated relict population (Martha's Vineyard, MA), as well as within an undisturbed population (Chesapeake Bay, MD), were very low, indicating that even historically these beetles were genetically depauperate, presumably as a result of frequent natural extinctions of local populations. Phylogenetic reconstruction using DNA sequences placed two remaining populations of C. d. dorsalis in evolutionarily distinct units. We also examined whether genetic distance can be used as an indicator of the taxonomic status of C. d. media Le Conte, the subspecies most closely related to C. d. dorsalis . The amount of sequence divergence between C. d. dorsalis and C. d. media was similar to the levels observed between species of the Cicindela puritana Le Conte group that were used as a reference for the minimal amount of sequence divergence between closely related species. These molecular techniques can provide information on the population structure and subdivision, the evolutionary history of the species, and the phylogenetic framework (used as basis for taxonomic decisions), which in many cases cannot be obtained in any other way. We also propose that C. d. dorsalis can be used as a model system for conservation genetics.
125 citations
123 citations
TL;DR: The numerical importance of bees as pollinators of rabbiteye blueberry, Vaccinium ashei Reade, in the southeastern United States is studied and abundance of H. laboriosa at V. ashei was found to be most variable regionally, least variable annually, and most predictable daily during a flowering season.
Abstract: We studied the numerical importance of bees as pollinators of rabbiteye blueberry, Vaccinium ashei Reade, in the southeastern United States. Most of the 27 bee species were rare at V. ashei flowers. Three taxa of bees were often abundant at V. ashei : the honey bee, Apis mellifera L.; queens of four bumble bee species ( Bombus spp.); and the southeastern blueberry bee, Habropoda laboriosa (F.). Most bee species that co-occur with cultivated V. ashei do not visit its flowers either because adults emerge late in the spring following bloom, or their tongues are too short to probe the flowers effectively. The more common bees varied in their regional, annual, and seasonal abundances at cultivated V. ashei , reflecting inherent differences in sociality, foraging predilections, voltinism, and adult phenologies. Our censuses showed that H. laboriosa is a Vaccinium specialist (2 yr, two states, four habitats). Compared with the other common bees, abundance of H. laboriosa at V. ashei was most variable regionally, least variable annually, and most predictable daily during a flowering season. For 6 yr, adult activity of Bombus queens and univoltine H. laboriosa generally spanned the season of V. ashei flowering. Spatial patchiness but local reliability of H. laboriosa may be an outcome of its oligolectic floral preferences. In contrast, polylectic honey and bumble bees were regionally ubiquitous. However, the temporal abundance of honey bees fluctuated markedly at V. ashei , perhaps reflecting their shifting preferences among competing members of a local flora.
110 citations
TL;DR: The high degree of behavioral plasticity observed seems to allow flies to respond efficiently to a heterogeneous and variable environment and to adopt control strategies based on habitat manipulation.
Abstract: We identified all essential Anastrepha obliqua (Macquart) resources (i.e., food, shelter, oviposition substrate [larval rearing medium], sites to perform sexual activities, and pupation medium) within a diversified agroecosystem (plum trees planted adjacent to mango trees), and examined the relationship between the spatial arrangement and temporal characteristics (e.g., variable degree of foliage coverage in plum trees) of habitat patches and resource use by local fly populations. Patterns of resource use were correlated with habitat characteristics (e.g., availability of shade, temperature, relative humidity, light intensity) and varied significantly between sexes. Overall, females used plum trees for feeding and oviposition, whereas males used them only for feeding. In contrast, females principally used mango trees for resting and feeding and males for sexual activities (courtship, copulation) and resting. We report significant differences in fly sightings according to sex, hour of day, and microhabitat. Of all fly sightings in the plum microhabitat ( n = 396), 72.2% were females. In the mango microhabitat, 33.5% of 424 individuals sighted were female. Flies moved back and forth between microhabitats, especially during early morning and late afternoon. We also provide data on sightings of the fly parasitoid Doryctobracon aerolatus (Szepligeti) in plum trees and adjacent native vegetation. The high degree of behavioral plasticity observed seems to allow flies to respond efficiently to a heterogeneous and variable environment. We discuss the theoretical and practical implications of our results with respect to insect behavioral responses to variable environments, insect movement, and control strategies based on habitat manipulation (use of trap crops).
108 citations
97 citations
TL;DR: A set of six primers was evaluated in the identification of a total of 19 clones of the following species: Myzus persicae (Sulzer), Rhopalosiphum padi (L.), Aphis gossypii (Glover), Aphis fabae, Aphis craccivora (Koch), and Acyrthosiphon pisum (Harris) as mentioned in this paper.
Abstract: Identification of six aphid species was possible using the random polymorphic amplified DNA (RAPD-PCR) technique. This is a variant of the polymerase chain reaction (PCR) in which a single primer of random sequence is annealed at low temperatures. A set of six primers was evaluated in the identification of a total of 19 clones of the following species: Myzus persicae (Sulzer), Rhopalosiphum padi (L.), Aphis gossypii (Glover), Aphis fabae (Scopoli), Aphis craccivora (Koch), and Acyrthosiphon pisum (Harris). Reactions made with three primers (OPA-02, OPA-07, and OPA-09) produced species-specific DNA bands. Some intraspecific polymorphism was also detected between clones of R. padi and M. persicae when reactions were primed with OPA-02 and OPA-07. Reproducibility of the RAPD-PCR reactions was tested when using two different DNA extraction procedures. The results indicated that the best reproducibility was obtained when using the isopropanol-precipitation extraction procedure. Amplification products were also obtained when working with single aphid extracts, although the percentage of successful reactions was partially reduced.
94 citations
TL;DR: Time after death affected the assemblage of species attracted, with Phaenicia coeruleiviridis a consistent early arriver and Cochliomyia macellaria (F.) delayed by ≈1 d.
Abstract: A midsummer field study, conducted over two seasons, involved replicate samples of chickens killed at the same time. Hens were exposed to insect activity during the periods 0–24, 24–48, 48–72 and 72–96 h after death, being protected in the meantime by fine-mesh screening. In total, 10,551 adult flies were trapped over the hens and comprised mainly Sarcophaga spp. (Sarcophagidae) and greenbottle blow flies (Calliphoridae). Time after death affected the assemblage of species attracted, with Phaenicia coeruleiviridis (Macquart) a consistent early arriver and Cochliomyia macellaria (F.) delayed by ≈1 d. Sarcophaga spp. arrived early at such carrion, and Phormia regina (Meigen) and Phaenicia sericata (Meigen) were recovered from trap catches and reared from samples of immatures collected from hens at all time periods after death.
78 citations
TL;DR: Results indicate that fly longevity can be sustained by carbohydrate obtained in the form of leachate on surfaces of host foliage, which explains the extensive “grazing” behavior of flies on nonvisible substances on host plant surfaces devoid of honeydew.
Abstract: In a preceding systematic study in an apple orchard and its surroundings, we identified several natural substances upon which apple maggot flies, Rhagoletis pomonella (Walsh), were observed to feed. The primary objective of this investigation was to assess the identified natural substances for their contribution to apple maggot fly longevity and fecundity. Tests were carried out in small laboratory cages and in large field cages containing potted host trees. Results indicate that fly longevity can be sustained by carbohydrate obtained in the form of leachate on surfaces of host foliage. This explains the extensive “grazing” behavior of flies on nonvisible substances on host plant surfaces devoid of honeydew. Egg development, however, was not sustained by host foliage leachate. Bird droppings, aphid honeydew, and to a lesser extent hawthorn fruit leachate, contributed to moderate fly fecundity, whereas preparations of leaf surface bacteria, pollen, insect frass, and uric acid did not support significant egg development. Fecundity was greatest where flies were exposed to enzymatic yeast hydrolysate. Some practical implications of a better understanding of R. pomonella nutritional ecology are discussed, including the development of improved fruit fly attractants based on the identification of volatiles from natural nitrogenous sources such as bird droppings or insect honeydews.
68 citations
TL;DR: The most striking feature of the mating behavior of wild Anastrepha striata Schiner flies is the formation of female-male pairs that interact for prolonged periods and exhibit elaborate courtship behaviors such as repeated labellum-to-labellum contacts.
Abstract: We describe the diel patterns of feeding, resting, oviposition, and mating behavior of wild Anastrepha striata Schiner flies. Observations were made in a greenhouse (5 m wide, 6 m long, 4 m tall) in which a total of 91 potted guava, sapodilla, orange, and mango trees had been placed. Overall, we found statistically significant differences in fly activity patterns depending upon the hour of day and sex of fly. Most flies (62.3%) emerged between 0900 and 1200 hours with no significant differences between sexes. Young flies (1–15 d of age) fed preferably on napkin strips soaked in a yeast hydrolysate–sucrose mixture, whereas older flies (>30 d of age) preferred ripe fruit. Bubbling and regurgitation behaviors were common and were correlated with feeding times. Individual flies regurgitated a mean of 23.5 ± 1.5 SE drops and reingested them within 12 ± 3.9 min. Oviposition activity by females (which included ovipositor dragging on the fruit surface) followed a bell-shaped pattern with a peak at 1200–1300 hours. Mean clutch size was 1.5 ± 0.13. A. striata mating behavior is very complex and encompasses short- and long-range interactions between males and females. A larger proportion of males called singly (91.3%), but lek formation was also observed (8.7% of all calling males did so in a lek). The most striking feature of the mating behavior (not previously reported in other Anastrepha species) is the formation of female-male pairs that interact for prolonged periods (mean of 21.3 ± 2.3 min, n = 245). While interacting, flies exhibit elaborate courtship behaviors such as repeated labellum-to-labellum contacts (during which actual male-female substance transfer takes place) and circular displacements in front of the mate. In 78 pairs studied in detail, we observed a mean of 13.3 ± 1.9 mating attempts per pair, with a mean duration of 7.3 ± 0.3 s per attempt. Most mating attempts were unsuccessful (unsuccessful/successful mating attempt ratio, 10:1). Actual copulations had a duration of 29.2 ± 2.3 min ( n = 45). A. striata behavior is discussed in relation to behavior of other Diptera (including Anastrepha ).
66 citations
TL;DR: An experiment on adult beetle diet showed that the provision of Sucrose water greatly increased longevity and fecundity over a distilled water control, but increasing the concentration of sucrose >5% did not significantly improve beetle performance.
Abstract: Procedures are described for establishing a laboratory colony of the eucalyptus longhorned borer, Phoracantha semipunctata F., and rearing the adult beetles on a continual basis. Adult beetles reared from naturally infested Eucalyptus logs were caged and provided with oviposition substrates (folded sheets of plastic). Techniques for handling and caring for eggs and neonate larvae are discussed. Larvae were individually transferred into shallow incisions in the bark of fresh logs. Total survivorship from neonate larvae to adult was ≈35%. Our procedures yielded an average of 63 adult progeny for every adult female, with a generation time of ≈2 mo during the summer. Beetle colonies were protected from pyemotid mites by dusting rearing logs with sulfur and from ants with granular diazinon. An experiment on adult beetle diet showed that the provision of sucrose water greatly increased longevity and fecundity over a distilled water control, but increasing the concentration of sucrose >5% did not significantly improve beetle performance.
TL;DR: It is suggested that studies that lack one or more of three criteria related to morphology, physiology, and natural behavior can serve as incentives for further investigations by sensory physiologists, behaviorists, and neuroethologists.
Abstract: Although a sense of hearing, or the possession of ears, has been ascribed to many insects in the past, some of these published examples may not represent adaptively evolved sensory capabilities or structures. Certain purported cases of neural or behavioral responses to sound, for example, may be attributed to the resonation of nonspecialized cuticle which results from the high sound intensities used in the experiments. In addition, cuticular structures have been identified as tympanal organs without having been shown to function as hearing organs. We recommend that three criteria related to morphology, physiology, and natural behavior be satisfied before concluding that a sense of hearing exists. In this article, we survey the literature for examples of studies that lack one or more of these criteria and suggest that these studies can serve as incentives for further investigations by sensory physiologists, behaviorists, and neuroethologists.
TL;DR: The results are consistent with a founder effect leading to the evolution of the species H. zea during colonization of the Americas by stray individuals of H. punctigera, and a new model for evolution in Helicoverpa is proposed.
Abstract: Natural populations of Heliothis virescens (F.) and Helicoverpa zea (Boddie) were studied using starch gel electrophoresis as part of a program to understand gene flow, insecticide resistance, and evolutionary relationships in the group. This paper treats the electrophoretic techniques developed and used in our laboratories, compares our results with those of other workers on Heliothis and Helicoverpa , suggests enzyme loci that might be used in chemical tests for species identification, and proposes a new model for evolution in Helicoverpa . Several new or little-known enzyme staining recipes are included. Of the 23 interpretable loci revealed, 14 (61%) were polymorphic in H. virescens and 12 (52%) were polymorphic in H. zea . We find considerably less enzyme polymorphism in both species that did T. P. Sluss and co-workers in either species, but we suggest that some of the polymorphisms found by the latter were artifactual. Based on the 23 loci run here, average expected heterozygosity in H. virescens (17.2%) was significantly greater than in H. zea (5.5%). Eleven loci were diagnostic between the two species. However, our results on diagnostic loci also differ from those of T. P. Sluss et al., again suggesting scoring problems in their laboratory. Our results with H. zea were compared with those for the Old World species Helicoverpa armigera (Hubner) and Helicoverpa punctigera (Wallengren) from Australia. At polymorphic loci, H. zea has a 61% reduction in heterozygosity compared with its probable closest Old World relative, H. armigera and a similar reduction compared with H. punctigera . If caused by genetic drift, this reduction in heterozygosity would have required a severe bottleneck, equivalent to ≈10 generations with an effective population size of only six individuals, in the population ancestral to the entire species of H. zea . Our results are consistent with a founder effect leading to the evolution of the species H. zea during colonization of the Americas by stray individuals of H. armigera or a close relative.
TL;DR: The phylogenetic analysis suggests that two lineages exist in the R. pomonella species group, one consisting solely of R. cornivora Bush, and the other, the remainder of the group, consisting of a complex of extremely similar taxa.
Abstract: New allozyme frequency data on die Rhagoletis pomonella (Walsh) species group, together with previously published data, are summarized to aid in identification of the species and in estimating the phylogeny of the group. Seven taxa were included in the study: the four described species, one host race or undescribed species infesting Cornus florida L. (flowering dogwood), and two outgroup species, each from a different species group. The phylogenetic tree was estimated by direct parsimony analysis of allele frequencies at 29 enzyme loci. To facilitate comparison with earlier electrophoretic studies, a UPGMA clustering of Nei unbiased genetic distance was also performed. The phylogenetic analysis suggests that two lineages exist in the R. pomonella species group, one consisting solely of R. cornivora Bush, and the other, the remainder of the group, consisting of a complex of extremely similar taxa. Support for the most parsimonious phylogeny is weak. The systematic status of the Cornus florida host-associated population and the evolution of fruit size preference in light of the allozyme phylogeny are discussed.
TL;DR: An analysis of morphological characters of the adult body surface, wings, and male and female reproductive anatomy failed to reveal any consistent differences among the species, even though some statistically significant differences in wing shape emerged from the study.
Abstract: Two new species and one new combination in the green lacewing genus Chrysoperla are presented, based principally on species-specific features of their substrate-borne, vibrational courtship songs. The three are North American taxa with broad geographical ranges. All were previously considered part of a single species, variously referred to as C. plorabunda (Fitch) (a Nearctic species) or C. carnea (Stephens) (a holarctic species that includes C. plorabunda ). An analysis of morphological characters of the adult body surface, wings, and male and female reproductive anatomy failed to reveal any consistent differences among the species that could be used to identify them, even though some statistically significant differences in wing shape emerged from the study. The new species are C. adamsi and C. johnsoni , with broadly overlapping geographical ranges in western North America. The name C. plorabunda is redefined to include only those individuals with courtship songs corresponding to an eastern North American population. As now restricted, C. plorabunda nonetheless ranges from the east to west coasts of North America and south at least to the Mexican border.
TL;DR: It is suggested that it is possible to reduce the defensiveness of Africanized colonies to levels not different from those of European colonies after only two generations of crossing Africanized queens to European drones.
Abstract: The defensive behavior of honey bee, Apis mellifera L., colonies of different genotypic composition was studied. Workers within colonies varied with respect to the proportion of their genotypes that were of African origin. Two components of defensive behavior were measured: the time it took for the first worker in a colony to respond and sting a moving leather patch, and the total number of stings deposited by workers in the patch during a 60-s interval following the first sting. Hybrid (F1) colonies were not different for either variable from feral-captured Africanized colonies. However, colonies of the two backcrossed generations had fewer stings in patches than Africanized colonies and did not differ from European colonies. Results suggest that the intense defensive behavior of Africanized bees is dominant over the less defensive behavior of the Europeans we tested. Results also suggest that it is possible to reduce the defensiveness of Africanized colonies to levels not different from those of European colonies after only two generations of crossing Africanized queens to European drones.
TL;DR: These F statistics indicate that the extent of a local panmictic population has an average diameter on the order of 8 km or less, suggesting a combination of high mobility and high population size.
Abstract: Starch gel electrophoresis was used to evaluate the genetic population structure of the tobacco budworm, Heliothis virescens (F.). A total of 1,836 adult male moths were collected from 60 trap sites throughout Texas, Louisiana, Mississippi, Arkansas, and Georgia during a 4-wk period in 1989. An average of 30.6 (±0.4) moths was electrophoretically analyzed per trap. Genotypic proportions showed no significant departures from Hardy-Weinberg expectations, suggesting random mating within populations. Population differentiation, measured by the standardized gene frequency variance, F st, was low ( F st = 0.002 ± 10−4) but highly significant. This indicates an average local population size, Nm , of 135 (±10 using a jackknife estimate), the highest value we can find reported. This figure suggests a combination of high mobility ( m ) and high population size ( N ). Hierarchical F statistics were estimated using three levels: (1) traps within localities, (2) localities (traps within 8 km of each other) within regions, and (3) regions (localities within 80 km of each other). There was significant heterogeneity at all distance scales; however, gene frequency variance between regions and variance between localities within regions was low compared with variance within localities. These F statistics indicate that the extent of a local panmictic population has an average diameter on the order of 8 km or less.
TL;DR: Habitat differences of the larvae of the species may not be related directly to differential adaptation to particular water conditions, and both species generally performed better than in tap water (control), and no consistent difference was detected in their responses to treehole water.
Abstract: In northern Kyushu, Aedes albopictus (Skuse) exploit various natural and artificial containers; A. riversi Bohart & Ingram exploit treeholes exclusively. Development, growth, and survival of larval A. albopictus and A. riversi were compared in water containing commercial tannic acid, in water containing decaying leaves of Camellia japonica L. and Elaeocarpus sylvestris (Lour.) Poir., and in treehole water collected in the field. In water containing tannic acid, the larval period was prolonged and adult size increased in both mosquito species. Mortality increased with an increase in tannic acid concentration, and, in particular, A. riversi showed higher mortality than A. albopictus at 100 mg/liter. In water containing decaying leaves, which was dark, acidic, and contained abundant tannin-lignin, the larval period was longer and adult size smaller in both mosquito species than in water with artificial diet but no leaf litter. This difference was partly a result of the low nutritional value of decaying leaves. Larval mortality was high in water with many E. sylvestris leaves because of the high acidity or high tannin-lignin content. In treehole water with artificial diet, both species generally performed better than in tap water (control), and no consistent difference was detected in their responses to treehole water. In general, performance in simulated treehole water of A. riversi larvae, the treehole species, was not better than that of A. albopictus , which used treeholes infrequently. Habitat differences of the larvae of the species may not be related directly to differential adaptation to particular water conditions.
TL;DR: Experimental evidence suggests that flies are attracted to flowers by an olfactory cue, although visual cues might be used at short range, while at least some specimens of each Megaselia species carried clumps of pollen, suggesting that they were of an appropriate size to carry out pollination.
Abstract: Thirty-two flowers of Aristolochia littoralis Parodi collected in Gainesville, FL, between 29 August and 29 September 1992 contained 349 phorid flies representing seven species of the genus Megaselia: M. scalaris (Loew), M. aurea (Aldrich), M. perdita (Malloch), and four unidentified species. Experimental evidence suggests that flies are attracted to flowers by an olfactory cue, although visual cues might be used at short range. Ninety-six percent of the flies (334) were males. The reason for this male-biased sex ratio is unknown, but it is possible that the attractive olfactory cue produced by the plant is sex-specific. At least some specimens of each Megaselia species carried clumps of pollen, suggesting that they were of an appropriate size to carry out pollination. Germination tests were conducted on seeds from 10 A. littoralis fruits. The mean germination rate for seeds from the 10 fruits was 56% (range, 4–92%).
TL;DR: The ovipositional response of a uniparental Korean strain of the parasite Meteorus pulchricornis offered first to third instars of the gypsy moth, Lymantria dispar, indicated that parasitization was significantly higher in hosts offered as second instars.
Abstract: The ovipositional response of a uniparental Korean strain of the parasite Meteorus pulchricornis (Wesmael) offered first to third instars of the gypsy moth, Lymantria dispar (L.), indicated that parasitization was significantly higher in hosts offered as second instars. Over their lifetimes, which averaged 44 d, females of M. pulchricornis offered 15 second instars per day deposited an average of 268 eggs and attacked an average of 194 hosts. Rates of parasitization and superparasitization averaged 32 and 31%, respectively. At 24°C, development from egg to adult required 16–32 d. The uniparental Korean strain of M. pulchricornis differed from the biparental European strain by its thelytokous mode of reproduction and by having a reduced tendency to attack third instars of gypsy moth, the preferred host for the European strain. Production of F1 males by a few individual females in quarantine suggested that biparental strains of M. pulchricornis are present in the Far East. Attempts to hybridize the uniparental Korean strain with the biparental European strain were unsuccessful.
TL;DR: Quantitative predictions of effect on sex ratio of differential parasitism of males and females by a cleptoparasitic bee, Holcopasites ruthae Cooper, are derived.
Abstract: Calliopsis pugionis Cockerell usually nests in dense aggregations, with up to 1,650 nests per m2, in areas of bare soil. A female provisions one cell each day with pollen from composites, here Encelia and Hemizonia , usually in three or four pollen foraging trips, followed by a trip in which she collects nectar and pollen for her own consumption. Matings take place both on flowers and at nest sites. Males compose 70.8% of the larvae provisioned. Investment sex ratio (M/F) ranges from 1.07 to 2.43 when estimated from several measures of cost, including adult dry weight, prepupal wet weight, meconia weight, pollen trip foraging time, total foraging time, and number of days. The best estimate of investment sex ratio is probably about 2. Quantitative predictions of effect on sex ratio of differential parasitism of males and females by a cleptoparasitic bee, Holcopasites ruthae Cooper, are derived. These account for only some of the male bias in investment sex ratio; other factors could include local resource competition.
TL;DR: A new species of mite was discovered parasitizing eggs of the lesser mealworm, Alphitobius diaperinus (Panzer), a serious cosmopolitan poultry pest, and is an obligate, apparently host-specific parasitoid that kills the egg upon which it feeds.
Abstract: A new species of mite, Acarophenax mahunkai Steinkraus & Cross, n. sp., was discovered parasitizing eggs of the lesser mealworm, Alphitobius diaperinus (Panzer), a serious cosmopolitan poultry pest. Acarophenax mahunkai is an obligate, apparently host-specific parasitoid that kills the egg upon which it feeds. Therefore, it may help control the lesser mealworm. The systematics and biology of A. mahunkai are presented here. In the laboratory, 51.0% of lesser mealworm egg masses were parasitized by one or more female mites. Male mites were not parasitic and had poor locomotory abilities. Significantly fewer lesser mealworm eggs hatched (23.9% egg hatch) in parasitized egg masses than in unparasitized egg masses (72.7%). Mite sex ratios were highly skewed, with means of 27.2 ± 3.9 female and 1.7 ± 0.2 male offspring produced per gravid mite. Physogastric female mites parasitizing lesser mealworm eggs gave birth to fertile adult females. The developmental time of the mites (3–5 d) was faster than that of lesser mealworm eggs (5–7 d).
TL;DR: Two European chrysomelids, Galerucella calmariensis (L.) and G. pusilla (Duftschmidt), show promise as biological control agents against the weed Lythrum salicaria L.salicaria, which would increase to five the number of GalerUcella species in North America.
Abstract: Two European chrysomelids, Galerucella calmariensis (L.) and G. pusilla (Duftschmidt), show promise as biological control agents against the weed Lythrum salicaria L. (purple loosestrife). G. calmariensis and G. pusilla are sympatric, share the same ecological niche on L. salicaria , and are separated by several morphological characters. These two Galerucella species were genetically compared with another sympatric species, G. grisescens (Joannis), found on Lysimachia vulgaris L. (garden loosestrife) in Europe, and to G. nymphaeae (L.), which occurs on water lilies and other wetland plants such as L. salicaria in Europe and the United States. Two additional species of Galerucella occur in North America: G. stefanssoni Brown, feeding on Rubus chamaemorus L. (cloudberry), and G. quebecensis Brown, feeding on Potentilla palustris (L.) Scop, (marsh-flower). Introduction and establishment of G. calmariensis and G. pusilla to combat L. salicaria would increase to five the number of Galerucella species in North America. The five species are keyed, described, and the adult and male genitalia are figured. An isozyme comparison of 33 loci among three species of Galerucella from Germany verified that G. calmariensis, G. pusilla , and G. grisescens are distinct species. G. calmariensis has a genetic marker represented by LDH-1. The clustering analysis based on genetic identities and some behavioral characters suggests that G. grisescens is more closely related to G. nymphaeae than to G. calmariensis or G. pusilla . The three United States samples of G. nymphaeae collected from two different host plants showed moderate differentiation. Mean heterozygosity ranged from 0.100 to 0.214 (mean = 0.157) across all six measured populations of G. calmariensis, G. pusilla, G. grisescens , and G. nymphaeae .
TL;DR: Prolonged progeny production by twice-mated females suggests a possible hypothesis for the continued presence of two mating strategies in the field.
Abstract: Second-male sperm precedence in the Mediterranean fruit fly from a single series of matings is maintained at a uniform rate over the effective female reproductive life span. Male reproductive fitness can drop significantly if a second male also mates with the same female; the magnitude of the drop is a function of the male genotypes. Females mated twice have as many or slightly more offspring over their effective reproductive period as do females mated once. However, twice-mated females have a significantly higher number of progeny during the fourth week after mating. Prolonged progeny production by twice-mated females suggests a possible hypothesis for the continued presence of two mating strategies in the field.
TL;DR: Compared with conspecific crosses, postzygotic barriers to gene exchange do not appear to be strong enough to account for the low number of hybrids found in mixed populations of Allonemobius fasciatus and A. socius.
Abstract: Allonemobius fasciatus (De Geer) and A. socius (Scudder) are small ground-dwelling crickets that meet and hybridize, to a limited extent, in a mosaic contact zone stretching from New Jersey to at least as far west as Illinois. To determine whether there is selection against hybridization, we compared heterospecific and hybrid crosses with conspecific crosses with regard to offspring production, viability, and development. Parental, F1, and F2 heterospecific and hybrid crosses produced considerable numbers of offspring, although some cross classes produced significantly fewer offspring than conspecific crosses. Differences in the number of offspring produced between heterospecific or hybrid crosses and conspecific crosses could be attributed to differences in the number of eggs laid rather than to differences in the percentage hatching. The time of hatching, the time required to reach adulthood, and hatchling-to-adult survival were similar in the various cross classes. Postzygotic barriers to gene exchange do not appear to be strong enough to account for the low number of hybrids found in mixed populations.
TL;DR: Caged Caribbean fruit flies, Anastrepha suspensa (Loew), held overnight without food fed more often on hydrolyzed brewers yeast and on sugar during the early morning than at any other time of the day.
Abstract: Caged Caribbean fruit flies, Anastrepha suspensa (Loew), held overnight without food fed more often on hydrolyzed brewers yeast and on sugar during the early morning than at any other time of the day. Flies provided yeast or sucrose overnight still fed principally during the morning hours on the following day. Both male and female consumption of 0.1 M sucrose solution was initially low when flies were 1 d old but increased daily until 1 wk after emergence and remained high thereafter. Consumption of yeast solution during the same time period increased over the first 5 d for both sexes, peaked 6 d after emergence, and fell off thereafter. Maximal rates of consumption of yeast solution were much higher, however, for females than for males. Peak yeast consumption in females coincided with a period of rapid ovarian development.
TL;DR: Spring behavior of adult plum curculios, Conotrachelus nenuphar (Herbst), was observed for 2 yr within field cages containing dwarf apple trees, finding dropping, crawling, and flying are important means of dispersal.
Abstract: Spring behavior of adult plum curculios, Conotrachelus nenuphar (Herbst), was observed for 2 yr within field cages containing dwarf apple trees. Variations in total activity were highly ( r 2 = 0.912) related to air saturation deficit. Differences in crawling, feeding, mating, and egg-laying behaviors were significantly related to phenological stages, but not to meteorological conditions. All frequent behaviors, except resting, were more frequent between 1800 and 0000 hours, or were equally frequent with respect to hour classes. Behaviors varied with tree height and substrates occupied. Total activity was greater in trees (32% of observations of adults) than on the ground (11% of observations), but crawling was equally frequent in both locations (16% of observations). Resting occurred mostly on the ground, and feeding mostly on fruits, but feeding also occurred occasionally on flowers and on recently grown shoots. Mating took place from “full bloom” to “fruit set” stages, and occurred mostly on twigs, in the upper half of trees. Falling from trees was often followed by crawling on the ground to adjacent trees, which were subsequently invaded. Plum curculios flying from tree to tree were seen landing on various host structures and on the walls of the cage. Thus, dropping, crawling, and flying are important means of dispersal.
TL;DR: A technique has been developed to distinguish between irradiated (sterile) and normal (wild or laboratory) sperm found in spermathecae of mated Mediterranean fruit flies, Ceratitis capitata, and may be further useful in distinguishing sperm among other interspecific or conspecific tephritid populations.
Abstract: A technique has been developed to distinguish between irradiated (sterile) and normal (wild or laboratory) sperm found in spermathecae of mated Mediterranean fruit flies, Ceratitis capitata (Wiedemann). Darkfield microscopy (1,000 × magnification) can be used to separate readily the sperm head lengths of irradiated males (20.5–29.0 μm; mean, 25.7) from those of wild males (27.5–33.0 μm; mean, 30.1). The sperm heads of laboratory adapted, nonirradiated males are intermediate in length compared with sperm from sterile and wild individuals. Sperm heads from three different wild populations in Hawaii were all strikingly similar in length. Field-collected females can be dissected to assess the mating frequency of released males in a sterile insect technique program. The frequency of multiple matings involving both types of males can also be measured. Two Bactrocera species found in Hawaii were examined and were found to have very similar sperm-head lengths when compared with each other, yet each had ≈3 μm longer average sperm-head lengths compared with those of C. capitata . The technique may be further useful in distinguishing sperm among other interspecific or conspecific tephritid populations. The potential effects of varying laboratory rearing or irradiation conditions on sperm-head length in tephritids remain to be investigated.
TL;DR: Preliminary data reinforce earlier findings that 17-year cicada mitochondrial genomes are remarkably homogeneous.
Abstract: Restriction fragment length polymorphisms (RFLP) in mitochondrial DNA (mtDNA) were examined using 12 different restriction enzymes for three populations (average 12 individuals per population) of brood IV of Magicicada septendecim (L.), one of three 17-year periodical cicada species. The goal of this research was to determine whether mtDNA variation among broods (year classes) exists and is phylogenetically useful. Brood IV was chosen for investigation because allozyme analysis of geographic variation within and among 10 periodical cicada year classes identified western 17-year broods III and IV as divergent from all the eastern 17-year broods. RFLP patterns scored for western brood IV were compared with those previously surveyed for eastern brood X populations. Our data showed brood IV restriction fragments to be identical in all three populations and identical to those of brood X with the exception of one (polymorphic) site which was present in most members of brood IV and had not been detected in brood X. Current research explores the potential for a new technique—restriction enzyme digests of a small section of the mitochondrial molecule amplified via the polymerase chain reaction (PCR—RFLP). Preliminary data reinforce earlier findings that 17-year cicada mitochondrial genomes are remarkably homogeneous.