Eriophyoid mites (Acari: Eriophyoidea) in Phyllocoptruta are reviewed. Two new species of Phyllocoptruta from Shaanxi Province, China, are described and illustrated: Phyllocoptruta huayangiana n. sp. on Rosa sericea Lindl. subsp. omeiensisi (Rolfe) A. V. Roberts (Rosaceae) and Phyllocoptruta clematoclethra n. sp. on Clematoclethra sp. Maxim. (Actinidiaceae). The new species described herein are vagrants on the undersurface of host leaves, causing no apparent injury.

Melanacanthus margineguttatus Distant and Riptortus macleani Schaffner (both Alydinae) and Leptocorisa oratorio (F.) (Micrelytrinae: Leptocorisini) are recorded from Guam, the last for the first time. Melanacanthus and M. margineguttatus are redescribed; Melanacanthus is compared with other alydine genera; R. macleani and L. oratoria are compared with related species; and some biological notes from the literature are discussed.

Field surveys indicate that declining colonies of honey bees, Apis mellifera L. (Hymenoptera: Apidae), suffer simultaneously from multiple stress factors, raising concern that multiple stressors could be interacting to compound bee stress in an additive or synergistic fashion. We tested two null hypotheses: 1) Varroa destructor Anderson & Trueman (Acari: Varroidae) (=varroa) and Aethina tumida Murray (Coleoptera: Nitidulidae) do not interact such that the number of one affects the number or density of the other and 2) bee damage from one does not change in response to changing levels of the other. In a split-split plot design replicated in 2 yr and two states, experimental apiaries were established and each manipulated to achieve one of five average ± SE colony adult A. tumida populations: 0; 285 ± 6; 721 ± 5; 1,544 ± 14; or 3,175 ± 90. Within each apiary, the population of varroa mites in each colony was manipulated to achieve one of three average ± SE colony mite populations: 763 ± 121; 1,111 ± 155; or 1,856 ± 300. On a one-way basis, there was a predictable increase in measures of bee morbidity with increasing densities of each pest. Colony varroa mite levels decreased as apiary-wide A. tumida levels increased. In contrast, colony levels of the honey bee mite, Acarapis woodi (Rennie) (Acari: Tarsonemidae), increased as colony varroa levels increased. Concerning measures of bee morbidity, varroa and A. tumida did not interact such that damage by one was affected by changing levels of the other. A treatment threshold established for varroa before the arrival of A. tumida has not changed during the years since A. tumida has become established in the region.

In most insects, geographic variations in voltinism exhibit latitudinal clines, which have been conventionally regarded as a result of climatic adaptation. In contrast, Ypthima multistriata Bulter (Lepidoptera: Satyridae) shows enigmatic patterns of voltinism, ranging from one generation a year, with adult emergence in June or midsummer; to two generations, with adults emerging in June and September; to several generations with adults emerging intermittently from spring to autumn. Local populations with different voltinism patterns are geographically intermingled, suggesting at best a weak relation between voltinism and climatic factors. Y. multistriata populations are highly localized and the species has suffered recent reductions in density, suggesting that the voltinism differences may be of phylogenetic origin and also leading to the species being classified as endangered. To examine whether the geographic variation in voltinism is phylogenetically constrained, we constructed genealogical trees and a haplotype network of populations of Y. multistriata. The phylogenetic analyses of the mitochondrial cytochrome oxidase I (COI) region revealed that phylogenetically close populations, despite close geographic proximity, often display different voltinism. The haplotype network showed the same trends. Similarly, an analysis of molecular variance revealed that the voltinism types hardly accounted for the variance. Thus, we concluded that geographic variation in voltinism of Y. multistriata is at best only slightly attributable to phylogenetic constraints and instead may be due mainly to adaptation to the unique ecological selective regime of each population.

Fruit flies (Tephritidae) and lance flies (Lonchaeidae) (Diptera) include pests of highest economic importance to horticulture around the world, because various species damage high value fruit crops, These Tephritoidea are the reason for quarantine barriers among many countries, limiting the commerce of fresh fruits and vegetables. Knowledge of frugivorous tephritoid species richness and their interactions with the host plants are extremely important to Integrated Pest Management. This paper presents the interactions of 15 species of Anastrepha Schiner, Ceratitis capitata (Wiedemann) (Tephritidae), and eight species of Neosilba McAlpine (Lonchaeidae) with 40 host fruit species. We discovered that Pouteria glomerata (Miquel) Radlkofer (Sapotaceae) is the host fruit of Anastrepha undosa Stone. A. zernyi Lima was associated with fruit of Anacardium othonianum Rizzini (Anacardiaceae). This is the first record of A. zernyi from the State of Mato Grosso do Sul, and of A. hastata Stone from Central Brazil, A. sorocula Zucchi and A. zenildae Zucchi were the tephritids that infested the highest number of host fruits, A. alveatoides Blanchard, A. distincta Greene, A. macrura Hendel, A. rheediae Stone and A. undosa Stone were recovered from only one species of host, and all of these associations are new records. Also established for the first time are the associations among eight species of Neosilba with 38 host species. N. zadolicha McAlpine and Steyskal, N. pendula (Bezzi), N. glaberrima (Wiedemann) and N. inesperata Strikis and Prado were the most polyphagous Lonchaeidae.

A method of estimating per capita rate of change for experimental populations in the absence of adult survival and fecundity schedules (r′) was proposed previously (J. Anim. Ecol. 53: 573–580; 1984). The method has been used repeatedly, although there has been no attempt to verify the relationship between r′ and the per capita growth rate in populations. This method was tested with laboratory populations of the mosquito Aedes albopictus (Skuse) (Diptera: Culicidae) growing at three larval densities. Survival and fecundity schedules enabled calculation of per capita growth rate, r, for each population, whereas measuring emergent females enabled the calculation r′. The capacity of r′ to predict r was significant, although a substantial amount of variation in r remained unaccounted for, and r′ overestimated r. The degree of overestimation of r by r′ was consistent across the three densities, and the regressions off and r′ versus density were similar. Overestimation of per capita rate of change by r′ is attributed largely to extensive adult longevity in laboratory conditions for this species, coupled with a lengthy reproductive period, in combination with prereproductive adult mortality, both of which are assumed to be negligible with the r′ method. Separate indicators of larval success were also tested for their predictions of r; only first day emergence and average development time were significant predictors although neither performed as well as r′. The r′ index accounted for the largest fraction of variation in r. Implications of overestimating r by r′ to estimating other population parameters are discussed.

In a previous study, we observed no spatial genetic structure in Mexican populations of the parasitoids Chelonus insularis Cresson (Hymenoptera: Braconidae) and Campoletis sonorensis Cameron (Hymenoptera: Ichneumomdae) by using microsatellite markers. In the current study, we investigated whether for these important parasitoids of the fall armyworm (Lepidoptera: Noctuidae) there is any genetic structure at a larger scale. Insects of both species were collected across the American continent and their phylogeography was investigated using both nuclear and mitochondrial markers. Our results suggest an ancient north-south migration of C. insularis, whereas no clear pattern could be determined for C. sonorensis. Nonetheless, the resulting topology indicated the existence of a cryptic taxon within this later species: a few Canadian specimens determined as C. sonorensis branch outside a clade composed of the Argentinean Chelonus grioti Blanchard, the Brazilian Chehnus flavicincta Ashmead, and the rest of the C. sonorensis individuals. The individuals revealing the cryptic taxon were collected from Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) on tomato (Lycopersicon spp.) and may represent a biotype that has adapted to the early season phenology of its host. Overall, the loosely defined spatial genetic structure previously shown at a local fine scale also was found at the larger scale, for both species. Dispersal of these insects may be partly driven by wind as suggested by genetic similarities between individuals coming from very distant locations.

Reproductive potentials were compared for a large invasive lady beetle, sevenspotted lady beetle, Coccinella septempunctata L. (Coleoptera: Coccinellidae), and a set of four smaller native North American species that have been displaced from alfalfa, Medicago sativa L., fields in Utah. The invader rapidly attained predominance in these fields during years when aphid populations were high. In a laboratory experiment, females were provided with excess numbers of their principal prey in these fields, pea aphids, Acyrthosiphon pisum (Harris). Among the five species, both the number and total volume of eggs (number × mean egg volume) produced per day increased with increasing female size and were greatest for C. septempunctata. Rates of reproduction also increased with increasing female size within species. Similarly sized females of C. septempunctata and transverse lady beetle, Coccinella transversoguttata richardsoni (Brown), laid similar total volumes of eggs per day, but females of the invasive species had more ovarioles and laid larger numbers of individually smaller eggs. In summary, when feeding on abundant prey in a habitat in which it predominates, the invasive C. septempunctata gains reproductive advantage over native, North American lady beetles, from its large body size and its investment in many small eggs. The results support the generalization that high fecundity linked with large body size may often be one important factor that promotes the dominance of introduced species over native competitors in resource-rich environments.

Within 2 yr of the arrival of the invasive container mosquito Aedes albopictus (Skuse), the previously dominant invasive mosquito Aedes aegypti (L.) disappeared from many Florida cemeteries. At some cemeteries, however, Ae. aegypti populations seem stable despite Ae. albopictus invasion. We sought to understand this variation in the outcome (exclusion, coexistence) of this invasion, given that previous experiments show that Ae. albopictus is the superior larval competitor. We tested experimentally the hypothesis that climate-dependent egg survivorship differs between exclusion and coexistence cemeteries and that differences in invasion outcome are associated with microclimate. Viability of eggs oviposited in the laboratory and suspended in vases at six cemeteries was significantly greater for Ae. aegypti than for Ae. albopictus, and greater in 2001 than in 2006. Cemeteries differed significantly in egg survivorship of Ae. albopictus, but not of Ae. aegypti, which is consistent with the hypothesis that Ae. albopictus suffers site-specific, climate-driven egg mortality that mitigates the competitive superiority of larval Ae. albopictus. Principal component (PC) analysis of microclimate records from vases during the experiments yielded three PCs accounting for >96% of the variance in both years of experiments. Multivariate analysis of variance of the three PCs revealed significant microclimate differences among the six cemeteries and between exclusion versus coexistence cemeteries. Stepwise logistic regression of egg survivorship versus microclimate PCs yielded significant fits for both species, and twice as much variance explained for Ae. albopictus as for Ae. aegypti in both years, Higher mortalities in 2006 were associated with high average daily maximum temperatures in vases, with lethal thresholds for both species at ≈40°C. From 1990 to 2007, vase occupancy by Ae. albopictus increased and that by Ae. aegypti decreased, with increasing seasonal precipitation at one well-sampled cemetery. Results support the hypothesis that locally variable climate-driven mortality of Ae. albopictus eggs contributes to patterns of exclusion of, or coexistence with, Ae. aegypti.

Oviparous species have evolved eggs with traits that provide protection, nutrients, or symbionts for the offspring. In the assassin bug genus Zelus (Hemiptera: Reduviidae), newly hatched first instars have been observed to collect a sticky substance from their eggs and coat it on their legs. Here, we tested the hypotheses that the sticky substance improves predation success and substrate adhesion ability of the Zelus renardii Kolenati first instar, Z. renaidii instars that had access to the sticky substance imposed higher mortality on adult flies and became dislodged at higher wind speeds than instars without access to sticky substance.

The alfalfa leafcutting bee, Megachile rotundata (F.) (Hymenoptera: Megachilidae), is widely used in western North America to enhance pollination of alfalfa, Medicago sativa L., grown for seed production. Feral populations have been documented but have been little-studied, We used trap-nests of a wide range of diameters (3–9 mm) to study a feral population at a wildflower seed farm in Montana. Adult females accepted all hole sizes but tended to provision nest tunnels of smaller diameters (3–4 mm) than those provided in managed populations (5–7 mm). Progeny, especially females, from intermediate- and large-diameter nests averaged larger body size that those in the two smallest nest-diameter classes. Offspring were often larger in nests with greater numbers of offspring, indicating that there was no trade-off between offspring size and number within nests. Individual nests tended to contain a relatively small range of progeny sizes and those sizes tended to vary among nests of the same diameter. Previous studies of M. rotundata indicate that heritability of body size is low, most offspring within nests are full siblings, and variation in offspring size is due to variation in the amount of provision provided by mothers. Thus, the fact that body size varied among families probably related to variation in provisioning capabilities among females. We also found evidence that offspring size varied spatially but that seasonal trends in offspring size were weak. Sex ratio varied among different nest sizes, but only the smallest and largest nests produced biased ratios. Sex ratios were less male-biased than in commercially managed populations of M. rotundata.

The California Channel Islands have been the focus of multiple conservation studies on charismatic vertebrates and plant species, but very few studies have focused on insects. In this study we examined the phylogeography of Coelus pacificus Fall (Coleoptera: Tenebrionidae), a dune-inhabiting darkling beetle, endemic to the islands. Our aim in this study is to decipher the relationships between C. pacificus and the congeneric species Coelus ciliatus Eschscholtz that is distributed on the mainland, to examine the biogeographic relationships of the islands and augment the conservation efforts on the islands with insect data. We sequenced 235 specimens of Coelus for the cytochrome oxidase I mitochondrial gene. We performed phylogenetic analyses to assess the historical relationships of the different species and islands. We also examined the connectedness of the islands by using pairwise φ;st and hierarchical analysis of molecular variance to test alternate hypotheses of geographical structure, Based on the phylogenetic analyses, C. pacificus is a valid, multi-island endemic species. Haplotypes were grouped into two clades: one clade composed of Santa Cruz, Santa Rosa, San Miguel, and San Nicolas; and the other clade composed of Santa Catalina and San Clemente. The highest haplotypic diversity was observed in San Clemente and San Nicolas islands, but all islands had unique haplotypes. Two haplotypes morphologically indistinguishable from C. pacificus formed a sister clade to C. ciliatus, suggesting either an ancient hybridization event or cryptic speciation. The California Channel Islands should be managed on a system wide basis, at least for some of the organisms or habitats and each island's population requires separate management to protect genetic integrity.

Males of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) produce the aggregation pheromones dominicalure-1 (DL1) and dominicalure-2 (DL2), which attract both sexes of the beetle to food source and for mating. The insect only releases these male-produced pheromones during feeding, and volatile emissions from other insect or plant species are not known to contain DL1 or DL2. Studies have suggested that overcrowding and the nutritional state of the adult could have an important effect upon life history parameters such as longevity, mating, and reproduction in the insect. In the current study, we used quantitative gas chromatographic techniques to examine the effect of temporary starvation and beetle density on pheromone dynamics in the insect. R. dominica males that were unfed immediately before testing released less quantity of pheromones compared with fed insects, but pheromone release returned to normal over time on resumption of feeding. Pheromone signaling in the beetle was affected by the interactions between food quantity and male density. The interactive effect showed that by increasing the quantity of food, thus reducing the density of males per quantity of food, the hitherto low rate of pheromone release observed in the insect was reversed and individual males release more pheromone, and thus a stronger signal for responders, as if they were alone with adequate food. The study also showed that the quantity of pheromone emitted per male declined with increasing beetle density and that this effect is stronger in the presence of other males than of females.

In Stenotus rubrovittatus (Heteroptera: Miridae), mating behavior consists of male courtship and female mating receptivity. This behavior was shown previously to be correlated with female age. The ovaries of S. rubmvittatus females start to develop in the absence of mating and the development is correlated with age. Accordingly, the relationships between female age and ovarian development that affect the mating behavior of S. rubrovittatus were examined. Male courtship behavior was most active toward 3-d-old females, and almost all 3-d-old females were receptive to male courtship. The ovaries of 3-d-old females showed either signs of oogenesis or the presence of mature eggs. Fifty percent of the males courted females regardless of the stage of ovarian developmental stage, whereas almost all of females with undeveloped ovaries refused male courtship. However, the fraction of males exhibiting courtship behavior and receptive females peaked after the start of oogenesis, These results suggest that S. rubrovittatus males are able to sense, and thus to court, females whose ovaries are at least partially developed. In some heteropterans, including S. rubrovittatus, some ovarian development is needed in order for mating to occur.

Leaf mines exhibit complicated patterns with crosses and branch structures. Mining patterns are hypothesized to be a result of selective feeding on leaf areas that are nutritionally rich or that are poor in chemical and structural defenses (the selective feeding hypothesis). The hypothesis was tested using the leafminer Ophiomyia maura Meigen (Diptera: Agromyzidae) by examining leaf anatomy and nutritional content of the host plant Aster microcephalus (Miq.) Franch. et Savat. variety ovatus (Franch. et Savat.) Soejima et Mot. Ito (Asteraceae). O. maura shows a specific mining pattern by preferentially mining the marginal part of the leaf. Cross sections of mined leaves revealed that O. maura consumed a layer of palisade parenchyma cells. The mining site of O. maura was limited to a particular area by the midrib and lateral veins, but not by minor veins, because midrib and lateral veins have well developed parenchyma cells around the vascular bundles and interrupted the palisade layer. By mining at the marginal part of the leaf, O. maura avoided the midrib and lateral veins, or pinnate venation of A. microcephalus. The nitrogen content of the marginal part of the leaf was higher than that of the inner part of the leaf, which also contributed to O. maura mining the marginal part of the leaf. The specific mining pattern of O. maura demonstrated that the leafminer could have developed an adaptive life-history strategy by responding in a most efficient manner to the arrangement of veins and the nutritional variability even at a within-leaf scale, following the selective feeding hypothesis.

The mating behavior of Hyalesthes obsoletus Signoret (Hemiptera: Cixiidae) was studied to determine the role of substrate-borne vibrational signals in partner recognition, pair formation, and courtship. Planthopper vibrational signals were detected from nettle, Urtica dioica L., cuttings by laser vibrometer. Either male or female could initiate the mating sequence that was divided into three sections: recognition, courtship and precopula. The females were the more vibrationally active gender in the recognition stage and males in the courtship and precopula stages. Four distinct syllables constituted the male repertoire and were emitted in different behavioral contexts. The male syllable 1 was used during the recognition duet, as a reply to female pulse trains and it formed, in combination with male syllable 4, the male precopula signal. This latter signal was emitted in the vicinity of a receptive female and accompanied by jerky lateral movements of the body and tapping of the legs to the substrate. Although nonduetting males emitted long trains composed of male syllable 2, males during the courtship phase emitted trains formed mainly by male syllable 3. Female vibrational signals consisted of pulses, emitted either in trains during the recognition phase or as single pulses, in reply to male trains in the courtship stage. In the precopula phase, the females ceased signaling. According to our results, in H. obsoletus the vibrational signals play a major role in stimulating the male search process and in ensuring the female acceptance.