Since its establishment in Florida in 2005, Scirtothrips dorsalis Hood, a highly polyphagous species, has become an economically important pest of ornamental plants and a potentially significant pest of vegetable and fruit crops. Fruit and vegetable production in Florida is trending toward significant adoption of organic methods and use of widely dispersed small fields in rapidly urbanizing landscapes. Landscape plants may serve as refugia from which S. dorsalis recruits can disperse to nearby fruit and vegetable plantings. Therefore, information on this pest's biology including how it is affected by various host species is needed to develop effective integrated pest management (IPM) programs. In the greenhouse and laboratory condition, we studied the effects of various host plants, development, diel flight activity, oviposition, and demographics of S. dorsalis. The pest preferred Jalapeño pepper and Knockout rose over the other hosts, and it was most active between 1000 and 1600 hours EST. Irrespective of the host species, the duration of each of the immature stadia varied within a narrow range, and their respective sizes were quite similar. Demographic parameters quantified included gross reproduction rate (GRR), net reproductive rate (R_o), intrinsic rate of increase per day (r_m), finite rate of increase per day (λ), and mean generation time (T). The pest population may increase by a factor of ≈ 1.09/d, so that it may double in 8 or 9d. The above information should be helpful in the development of sound programs to manage S. dorsalis on various crops and in the formulation of detection strategies by quarantine officers.

Granivory is a specialized food habit in the predominantly carnivorous beetle family Carabidae. Most studies of carabid granivory have been conducted under laboratory conditions; thus, our knowledge of the feeding ecology of granivorous carabids in the field is insufficient. I conducted field observations of climbing behavior and seed predation by adult carabids in a lowland area of eastern Japan, from early October to late November in 2008. This is the first systematic field observation of the feeding ecology of granivorous carabids in the temperate zone. In total, 176 carabid individuals of 11 species were observed, with 108 individuals feeding on plant seeds/flowers. Each carabid species was primarily observed feeding on a particular plant species. Frequently observed combinations were: Amara gigantea Motschulsky on Humulus scandens (Loureiro) Merrill (Moraceae) seed, Amara lucens Baliani on Artemisia indica Willdenow (Asteraceae) flower, and Amara macronota (Solsky) and Harpalus (Pseudoophonus) spp. on Digitaria ciliaris (Retzius) Koeler (Poaceae) seed. In all but one species, the sex ratio of individuals observed feeding was female-biased. In Am. gigantea and Am. macronota, a larger proportion of females than males ate seeds. In the three Amara species, copulations on plants, with the female feeding on its seeds/flowers, were often observed. These observations may indicate that, whereas females climb onto plants to feed on seeds, males climb to seek females for copulation rather than forage. Because granivorous carabids play important roles as weed-control agents in temperate agro-ecosystems, the present results would provide valuable basic information for future studies on this subject.

We analyzed the spatial distribution and dispersal of codling moth, Cydia pomonella (L.), adults within two heterogeneous agroecosystems typical of central Chile: commercial apple, Malus domestica Borkhausen, orchards surrounded by various unmanaged host plants. Both a geostatistical analysis of catches of adult males with a grid of sex pheromone-baited traps and an immunological self-marking technique combined with traps baited with a male and female attractant were used. The spatial analyses identified the key sources of moths within these diverse landscapes. Codling moth catches in traps were spatially associated within distances of ≈150–300 m. Similarly, the mean distance from the immunological self-marking plots within the commercial apple orchard to the traps that captured marked adults was 282 m. In contrast, the mean distance in the capture of marked moths from unmanaged self-marking plots to a commercial orchard was 828 m. These data suggest that the success of any future areawide management programs for codling moth in Chilean pome fruit must include a component for managing or removing noncommercial hosts that surround orchards. This analysis also suggests that the selection pressure for resistance imposed by insecticide sprays within managed orchards is likely dampened by the influx of susceptible moths from unmanaged sites common in central Chile.

Thrips are key pests of mango, Mangifera indica (L.), in Malaysia, including the Northern Peninsular. As Penang has year-round equatorial climate and high of rainfall, the populations of thrips may be subject to variations in composition and size. With a goal of developing an appropriate control strategy, a survey was conducted in Penang to determine species composition and abundance in relation to some environmental factors. Sprayed and unsprayed orchards were sampled on weekly basis through two flowering seasons of 2009 using CO₂ collection technique. Larval population falling into the ground to pupate and adults emerging from the soil were investigated in both orchards. Thrips hawaiiensis (Morgan) and Scirtothrips dorsalis (Hood) were the most prevalent species in the sprayed and the unsprayed orchards, respectively. The abundance of thrips was high during the flowering period of the dry season and decreased during the flowering period of the rainy season. This latter period coincided with decreased temperature and increased relative humidity. Percentage of adult emergence from the soil was lower in the rainy season than recorded in the dry season in both orchards. Taken together, these observations suggest that T. hawaiiensis and S. dorsalis are the main thrips species pests of mango panicles in Penang. Direct control with insecticides focusing on these two species may help to reduce cosmetic injuries and other damages on mango fruits.

The distribution of phytophagous stink bugs and associated boll injury in margins of cotton fields bordering various agronomic crops and woodlands were studied in 2007 and 2008. Two commercial cotton fields, ranging in size from 7.8 to 12.1 ha in Barnwell and Lee Counties, SC, were sampled weekly each year along predetermined transects at 0, 5, 10, and 25 m from the outside margin into the cotton field. Stink bugs were sampled using a ground cloth (0.91 by 0.91 m), and quarter-sized bolls (≈2.5 cm in diameter) were collected and examined for internal damage. Density (bugs/row-m) of total stink bugs (adults plus nymphs) was greatest in cotton adjacent to peanut. Boll injury was significantly greater in cotton adjacent to soybean and peanut than in cotton next to other habitats, including corn, cotton, and woodlands, during midseason. Density of nymphs was greatest in cotton adjacent to peanut during mid and late season. Densities of total stink bugs and adults were greatest in cotton immediately adjacent (0 m) to all bordering crops and decreased as distance from the margin increased. Boll injury was greatest in cotton immediately adjacent (0 m) to the bordering crop in mid and late season. Because densities of stink bugs and boll injury vary spatially and temporally along field margins of cotton and can vary significantly based on the adjacent crop, such factors should be considered when developing integrated pest management strategies in cotton.

Over a period of 19 yr, the harvestman (Opiliones) community associated with the lowbush blueberry agro-ecosystem in Maine was studied. Eight species representing five genera, four subfamilies, and two families of harvestmen belonging to the suborder Eupnoi were collected. The harvestman community was dominated by two introduced, synanthropic species: Phalangium opilio in all but 1 yr (that year dominated by Rilaena triangularis). Rilaena was recorded for the first time from eastern North America. Relative abundance of harvestman adults increases throughout the season and the temporal pattern of trap capture does not refute speculated life cycles of the harvestmen being univoltine with overwintering eggs. Some blueberry management practices were found to affect trap capture. We did find that on average (with opposite results 1 yr) trap captures are greater in pruned fields than in fruit-bearing fields. Organic fields were found to have higher relative abundance of harvestmen than conventionally managed fields. Conventionally managed fields with reduced-risk insecticides showed no difference in harvestmen relative abundance compared with those conventionally managed fields using the older more persistent organophosphate insecticides. Insecticide trials with common insecticides used in blueberry insect pest management showed that the organophosphate insecticide, phosmet, and the pyrethroid insecticide, esfenvalerate, were detrimental to P. opilio adults when exposed to leaf residues, whereas the reduced-risk insecticide, spinosad, showed no negative effects compared with nonsprayed foliage.

The outcomes of grasshopper responses to both vertebrate grazing and fire vary across grassland ecosystems, and are strongly influenced by local climactic factors. Thus, the possible application of grazing and fire as components of an ecologically based grasshopper management strategy must be investigated in regional studies. In this study, we examined the effects of grazing and fire on grasshopper population density and community composition in a northern Great Plains mixed-grass prairie. We employed a large-scale, replicated, and fully-factorial manipulative experimental design across 4 yr to examine the separate and interactive effects of three grazing systems in burned and unburned habitats. Grasshopper densities were low throughout the 4-yr study and 1 yr of pretreatment sampling. There was a significant fire by grazing interaction effect on cumulative density and community composition, resulting from burned season long grazing pastures having higher densities than unburned pastures. Shannon diversity and grasshopper species richness were significantly higher with twice-over rotational livestock grazing. The ability to draw strong conclusions regarding the nature of species composition shifts and population changes in the presence of fire and grazing is complicated by the large site differences and low grasshopper densities. The results reinforce the importance of long-term research to examine the effects of habitat manipulation on grasshopper population dynamics.

Exotic ant species are a primary threat to ant biological diversity, posing a negative impact to native ant communities. In this study, we examine species richness of ants (family Formicidae) in Acadia National Park, ME, as a fundamental step toward understanding the present impact of the exotic species Myrmica rubra on native ant species. Twelve habitat types were sampled, along six transects, with pitfall traps, visual searching, bait traps, and leaf litter extraction, and the aid of 34 volunteers. We report 42 species of ants in Acadia National Park, comprising five subfamilies (Amblyoponinae, Dolichoderinae, Formicinae, Myrmicinae, and Ponerinae) and 15 genera; the cataloged species represents 75% of the species originally recorded in the area by Procter (1946). Our findings suggest M. rubra is currently not a dominant species throughout the entire island. However, where this species has invaded locally, few competing native species coexist. The species Lasius alienus, Formica subsericea, Myrmica detritinodis, Camponotus herculeanus, Formica argentea, Formica aserva, and Tapinoma sessile occurred most often in our survey. We report the ant species Amblyopone pallipes and Dolichoderus mariae as two new records for the state of Maine.

We documented fruit fly-host associations and infestation rates over 5 yr in the state of Bahia, Brazil, by systematically collecting native and introduced fruits in backyard and commercial orchards, experimental stations, and patches of native vegetation. Fruit were collected in multiple sites in the southern and southernmost regions of Bahia. A total of 942.22 kg from 27 fruit species in 15 plant families was collected throughout this study. Of these, 15 plant species from six families were infested by Anastrepha species. A total of 11,614 fruit flies was reared from the fruit (5,178 females and 6,436 males). No specimens of Ceratitis capitata (Wiedemann) were recovered. Eleven Anastrepha species were recovered from the collected fruit: Anastrepha antunesi Lima (0.04%), Anastrepha distincta Greene (0.1%), Anastrepha fraterculus (Wiedemann) (53.5%), Anastrepha leptozona Hendel (4.5%), Anastrepha manihoti Lima (0.1%), Anastrepha montei Lima (1.0%), Anastrepha obliqua (Macquart) (33.0%), Anastrepha pickeli Lima (2.0%), Anastrepha serpentina (Wiedemann) (1.0%), Anastrepha sororcula Zucchi (3.0%), and Anastrepha zenildae Zucchi (1.8%). We recovered 1,265 parasitoids (Hymenoptera: Braconidae) from Anastrepha pupae. Three species of braconids were found to parasitize larvae of nine Anastrepha species. The most common parasitoid species recovered was Doryctobracon areolatus (Szépligeti) (81.7%), followed by Utetes anastrephae (Viereck) (12.2%) and Asobara anastrephae (Muesebeck) (6.1%). We report A. fraterculus infesting Malay apple Syzygium malaccense (L.) Merr. & L. M. Perry and A. fraterculus, A. sororcula, and A. zenildae infesting araza Eugenia stipitata McVaugh for the first time in Brazil.

We examined the arthropod community on eastern hemlock, Tsuga canadensis (L.) Carr, in the context of its role in providing potential prey items for hemlock-associated web-weaving spiders. Using sticky traps simulating spider webs, we evaluated what prey items are available to web-weaving spiders in eastern hemlock based on web orientation (horizontal versus vertical) and cardinal direction. We found that the overwhelming majority (>70%) of prey items available to spiders in hemlock canopies were Diptera. Psocoptera, Hymenoptera, and Hemiptera comprised most of the remaining potential prey. A significant direction × orientation interaction, and greater trap capture in some direction-orientation combinations, suggests that spiders might locate their webs in eastern hemlock canopies for thermoregulatory purposes, ultimately optimizing prey capture. We also evaluated these findings in the context of hemlock infestation by the invasive hemlock woolly adelgid, Adelges tsugae Annand. The adelgid is a sedentary insect with a mobile crawler stage that provides a readily available, easily obtained food source for predators in hemlock canopies. However, an abundance of alternative prey will affect within canopy spider distribution and the potential intensity with which spiders consume these prey. Understanding the response of spiders to potential prey availability is essential to understanding the trophic interactions involving these predators and their potential for influencing herbivore populations.

Agricultural intensification is linked to reduced species richness and may limit the effectiveness of predators in agricultural systems. We studied the abundance, diversity, and species composition of wood-nesting ants and frequency of parasitism of poneromorph ants in coffee agroecosystems and a forest fragment in Chiapas, Mexico. In three farms differing in shade management and in a nearby forest fragment, we surveyed ants nesting in rotten wood. We collected pupae of all poneromorph ants encountered, and incubated pupae for 15 d to recover emerging ant parasites. If no parasites emerged, we dissected pupae to examine for parasitism. Overall, we found 63 ant morphospecies, 29 genera, and 7 subfamilies from 520 colonies. There were no significant differences in ant richness or abundance between the different sites. However, there were significant differences in the species composition of ants sampled in the four different sites. The parasitism rates of ants differed according to site; in the forest 77.7% of species were parasitized, and this number declined with increasing intensification in traditional polyculture (40%), commercial polyculture (25%), and shade monoculture (16.6%). For three of four poneromorph species found in >1 habitat, parasitism rates were higher in the more vegetatively complex sites. The result that both ant species composition and ant parasitism differed among by site indicates that coffee management intensification affects wood-nesting ant communities. Further, coffee intensification may significantly alter interactions between ants and their parasites, with possible implications for biological control in coffee agroecosystems.

Economic and biological consequences are associated with exotic ambrosia beetles and their fungal associates. Despite this, knowledge of ambrosia beetles and their ecological interactions remain poorly understood, especially in the oak—hickory forest region. We examined how forest stand and site characteristics influenced ambrosia beetle habitat use as evaluated by species richness and abundance of ambrosia beetles, both the native component and individual exotic species. We documented the species composition of the ambrosia beetle community, flight activity, and habitat use over a 2-yr period by placing flight traps in regenerating clearcuts and older oak—hickory forest stands differing in topographic aspect. The ambrosia beetle community consisted of 20 species with exotic ambrosia beetle species dominating the community. Similar percentages of exotic ambrosia beetles occurred among the four forest habitats despite differences in stand age and aspect. Stand characteristics, such as stand age and forest structure, influenced ambrosia beetle richness and the abundances of a few exotic ambrosia beetle species and the native ambrosia beetle component. Topographic aspect had little influence on ambrosia beetle abundance or species richness. Older forests typically have more host material than younger forests and our results may be related to the amount of dead wood present. Different forms of forest management may not alter the percent contribution of exotic ambrosia beetles to the ambrosia beetle community.

Invasive ant species can have dramatic impacts on native ants, through direct predation and by usurping common resources. Most invasive ants and many native ants use honeydew, produced by phloem-sucking hemipterans. Because colonies of invasive ants can become very large after establishment, these ants may facilitate greater hemipteran trophobiont population growth compared with their sympatric native ant counterparts. We examined the population growth of an aphid mutualist, Aphis gossypii, and a nonmutualist, Myzus persicae, exposed to two Dolichoderine ants, Linepithema humile, a globally widespread invasive species, and Tapinoma sessile, a widespread co-occurring native ant, in North America in an enemy-free laboratory study. L.humile worker foraging activity was at least twice that of T.sessile, and populations of the myrmecophile, A. gossypii, were greater when exposed to L. humile than T.sessile, possibly caused, in part, by more frequent encounters with L. humile. L. humile ignored M. persicae when A.gossypii was absent, whereas T.sessile preyed on it. Both ant species preyed on M. persicae when A. gossypii was also present. This suggested that both ants may assess nutritional gains from aphid species (i.e., honeydew versus body tissue), eliminating less productive aphids competing for host plant space. Through their impact on populations of hemipteran mutualists, we suggest that colonies of L.humile and perhaps other invasive ants may acquire more honeydew than native ants, thereby fueling colony growth that leads to numerical dominance and widespread success in introduced environments.

Interspecific competition between parasitoid larvae may influence the size, structure, and stability of the population, leading to a reduction in total parasitism and thus restricting the pest control. Aphidius ervi (Haliday) and Praon volucre (Haliday) are endoparasitoids that possess a wide host range and present considerable potential for the biological control of the aphid Macrosiphum euphorbiae (Thomas). The larval competition between A. ervi and P. volucre, and the possible intrinsic competitive superiority of one of the parasitoids in M. euphorbiae, have been studied. In single parasitism experiments, mated parasitoid females (n = 10) were maintained individually in contact with M. euphorbiae hosts (n = 30) inside petri dishes containing lettuce leaf discs and maintained in environmental chamber at 22 ± 1°C, 70 ± 10% RH, and 12-h photophase. The multiple parasitism experiments consisted of exposing single parasitized aphids (n = 120) to the second parasitoid species. Two oviposition events were performed with a 4-h interval between them, namely the following: sequence A (oviposition by A. ervi, followed by P. volucre) and sequence B (oviposition by P. volucre, followed by A. ervi). Oviposition sequence A generated 24 A. ervi and 55 P. volucre adults, whereas oviposition sequence B generated 23 and 49 adults. P. volucre is an intrinsically superior competitor compared with A. ervi, and the use of the two species simultaneously may result in competitive exclusion and influence the stability of the parasitoid population.

Three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff [Hymenoptera: Encyrtidae]) of the mealybug Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) were studied for their host instar susceptibility and sex ratio, host instar selection, and interspecific competition in the laboratory. All three parasitoids were able to develop in the second instars, third-instar females, and adult females of P. marginatus. No progeny emerged from first-instar mealybugs. The proportion of female emergence was increased with increasing host size. Parasitoids selected their host instars for oviposition when they had a choice. Between secondand third-instar hosts, A. papayae and P. mexicana had significantly higher parasitism in second-instar mealybugs, whereas A. loecki had higher parasitism in the third-instar mealybugs. When competed with either one or two parasitoid species, A. papayae was significantly more successful in second-instar hosts and A. loecki was significantly more successful in third-instar mealybugs. P. mexicana was significantly less competitive when with A. papayae in both second and third instars, with A. loecki in third instars and with both A. papayae and A. loecki in second and third instars. Overall, A. papayae provided a better control of the host, when present singly or with the other two parasitoids. This information is important in evaluating the efficiency of A. papayae, A. loecki, and P. mexicana and understanding the outcome of their recovery and establishment in field studies conducted in Florida.

Cohorts of emerald ash borer larvae, Agrilus planipennis Fairmaire, were experimentally established in July of 2008 on healthy green ash (Fraxinus pennsylvanica) trees in two wooded plots at each of three sites near Lansing, MI, by caging gravid emerald ash borer females or placing laboratory-reared eggs on trunks (0.5–2 m above the ground) of selected trees. One plot at each site was randomly chosen for release of two introduced larval parasitoids, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), whereas the other served as the control. Stage-specific mortality factors and rates were measured for all experimentally established cohorts and for associated wild (i.e., naturally occurring) emerald ash borer immature stages via destructive sampling of 2.5 m (above the ground) trunk sections of cohort-bearing trees in the spring and fall of 2009. Host tree defense was the most important mortality factor, causing 32.0 to 41.1% mortality in the experimental cohorts and 17.5 to 21.5% in wild emerald ash borer stages by spring 2009, and 16.1 to 29% for the remaining experimental cohorts, and 9.9 to 11.8% for wild immature emerald ash borer stages by fall 2009. Woodpecker predation was the second most important factor, inflicting no mortality in the experimental cohorts but causing 5.0 to 5.6% mortality to associated wild emerald ash borer stages by spring 2009 and 9.2 to 12.8% and 3.2 to 17.7%, respectively, for experimental cohorts and wild emerald ash borer stages by fall 2009. Mortality from disease in both the experimental and wild cohorts was low (<3%) in both the spring and fall sample periods. In the fall 2009 samples, ≈1.5% of experimental cohorts and 0.8% of the wild emerald ash borer stages were parasitized by T. planipennisi. While there were no significant differences in mortality rates because of parasitism between parasitoid-release and control plots, T. planipennisi was detected in each of the three release sites by the end of the study but was not detected in the experimental cohorts or associated wild larvae in any of the three control plots.

In South Africa, modified Bt (Cryl Ac) cotton cultivars and organic ones coexist. This raises the question of the risk of dissemination of genetically modified (GM) pollen to non-GM crops by visiting insects. We inventoried the flower-visiting insects in Bt and non-Bt cotton fields of the South African Highveld region and investigated their role in pollen dispersal. Their diversity and abundance varied slightly among sites, with Astylus atromaculatus as the predominant insect on both Bt and non-Bt cotton flowers. The other major flower-visiting species were Apis mellifera and solitary Apidae. No differences were found in the abundance of each taxum between Bt and non-Bt cotton except for Scoliidae and Nitidulidae, which were scarce overall (<0.5%) but more abundant on the non-Bt flowers in the central area of the field at one site. The pollen load on A. atromaculatus was as high as on Apis mellifera. Cage tests showed that A. atromaculatus can pollinate female cotton plants by transferring pollen from male donor plants. In the field, the flight range of this insect was generally short (25 m), but it can occasionally reach up to 200 m or even more. This study therefore highlights that A. atromaculatus, commonly regarded as a pest, could be an unexpected but efficient pollinator. Because its population density can be high, this species could mediate unwanted cotton pollen flow when distances between coexiting fields are not sufficient.

A greenhouse experiment was conducted to evaluate the effect of soil-dwelling larvae of the western corn rootworm, Diabrotica virgifera virgifera LeConte, on infection of maize roots by the mycotoxin-producing plant-pathogenic fungus, Fusarium verticillioides (Saccardo) Nirenberg (synonym = Fusarium moniliforme Sheldon). The time and order of application of F. verticillioides and western corn rootworm were varied in three different treatments to investigate the influence of timing on root colonization of F. verticillioides and western corn rootworm larval development. Root feeding by western corn rootworm larvae increased root colonization by F. verticillioides (as determined by real-time polymerase chain reaction) up to 50-fold when a high inoculum (10⁷ spores/plant) of F. verticillioides was applied before western corn rootworm eggs were added. This effect was stronger the earlier F. verticillioides was applied relative to the time of western corn rootworm egg application but was only significant for the high F. verticillioides inoculum density treatment; F. verticillioides colonization was not increased when a low F. verticillioides inoculum density (10⁶ spores/plant) was applied. F. verticillioides slightly suppressed larval development in that the ratio of second- to third-instar larvae was higher in treatments with F. verticillioides than without F. verticillioides. F. verticillioides reduced western corn rootworm head capsule width when applied before or simultaneously with western corn rootworm. The results of this study are discussed focusing on conditions that favor root colonization by F. verticillioides and its influence on western corn rootworm larval development.

We investigated how host plant phenology and plant species affected longevity, reproduction, and feeding behavior of an invasive weevil. Phyllobius oblongus L. (Coleoptera: Curculionidae) is common in northern hardwood forests of the Great Lakes Region. Adults emerge in spring, feed on foliage of woody understory plants, and oviposit in the soil. Preliminary data indicate that adults often feed on sugar maple, Acer saccharum Marshall, foliage early in the season, then feed on other species such as raspberry, Rubus spp. Whether this behavior reflects temporal changes in the quality of A. saccharum tissue or merely subsequent availability of later-season plants is unknown. We tested adult P. oblongus in laboratory assays using young (newly flushed) sugar maple foliage, old (2–3 wk postflush) sugar maple foliage, and raspberry foliage. Raspberry has indeterminate growth, thus always has young foliage available for herbivores. Survival, oviposition, and leaf consumption were recorded. In performance assays under no-choice conditions, mated pairs were provided one type of host foliage for the duration of their lives. In behavioral choice tests, all three host plants were provided simultaneously and leaf area consumption was compared. Adults survived longer on and consumed greater amounts of young maple and raspberry foliage than old maple foliage. P. oblongus preferred young maple foliage to old maple foliage early in the season, however, later in the growing season weevils showed less pronounced feeding preferences. These results suggest how leaf phenology, plant species composition, and feeding plasticity in host utilization may interact to affect P. oblongus population dynamics.

Development, survivorship, longevity, reproduction, and life table parameters of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar), were examined in the laboratory using three host plants, sunflower (Helianthus annuus L.), Chrysanthemum morifolium L., and euonymus (Euonymus japonica Thurb.). Females deposited similar-sized egg masses on all three plants. Hatching was highest with eggs deposited on euonymus and lowest for those deposited on sunflower. Embryonic development time among host plants was similar while nymph development time was shortest on sunflower and longest on euonymus. Nymph survival to adulthood ranged from 32% on euonymus to 82% for those reared on sunflower. Adult females had similar life spans on sunflower and chrysanthemum. H. vitripennis completed a lengthy egg-to-adult development on euonymus, however, mating did not occur. The onset of mating was contingent on maturation of adult females. The majority of mating activity occurred within the first three days after onset. Premating periods ranged from 6 to 7 d on sunflower to 27 d on chrysanthemum, with overall mating rates of 77.4 and 19.8%, respectively. Females typically mated more than once and they had the longest oviposition period and highest egg production on sunflower; ≈50 and 67% of total number of eggs were deposited within first 45 d after the start of oviposition on sunflower and chrysanthemum, respectively. Adult size and weight related to which host plant was consumed throughout development. Greater intrinsic and finite rates of increase and net reproduction rate, and shorter population doubling time occurred when the sharpshooters were allowed to develop on sunflower. The overall developmental and reproductive parameters obtained in this study indicate that a mixed host plant system, composed of sunflower and euonymus or chrysanthemum plants, is an efficient means for optimizing egg production and colony maintenance of the glassy-winged sharpshooter.

Granivory is a specialized food habit in the predominantly carnivorous beetle family Carabidae. Most studies of carabid granivory have been conducted under laboratory conditions; thus, our knowledge of the feeding ecology of granivorous carabids in the field is insufficient. I conducted field observations of climbing behavior and seed predation by adult carabids in a lowland area of eastern Japan, from early October to late November in 2008. This is the first systematic field observation of the feeding ecology of granivorous carabids in the temperate zone. In total, 176 carabid individuals of 11 species were observed, with 108 individuals feeding on plant seeds/flowers. Each carabid species was primarily observed feeding on a particular plant species. Frequently observed combinations were: Amara gigantea Motschulsky on Humulus scandens (Loureiro) Merrill (Moraceae) seed, Amara lucens Baliani on Artemisia indica Willdenow (Asteraceae) flower, and Amara macronota (Solsky) and Harpalus (Pseudoophonus) spp. on Digitaria ciliaris (Retzius) Koeler (Poaceae) seed. In all but one species, the sex ratio of individuals observed feeding was female-biased. In Am. gigantea and Am. macronota, a larger proportion of females than males ate seeds. In the three Amara species, copulations on plants, with the female feeding on its seeds/flowers, were often observed. These observations may indicate that, whereas females climb onto plants to feed on seeds, males climb to seek females for copulation rather than forage. Because granivorous carabids play important roles as weed-control agents in temperate agro-ecosystems, the present results would provide valuable basic information for future studies on this subject.

Herbivores on plants frequently interact via shared resources. Studies that have examined performance of herbivores in the presence of other herbivores, however, have often focused on above-ground feeding guilds and relatively less research has examined interactions between below-and above-ground consumers. We examine how soybean aphid, Aphis glycines (Matsumura) an above-ground phloem-feeding herbivore, interacts with a below-ground plant parasite, soybean cyst nematode, Heterodera glycines (Ichinohe) through their shared host plant, soybean (Glycine max L). Laboratory experiments evaluated the preference of alate (flight-capable) soybean aphids toward plants either infected with soybean cyst nematode or uninfected controls in a simple choice arena. Alate soybean aphids preferred uninfected soybean over soybean cyst nematode-infected plants: 48 h after the releases of alate aphids in the center of the arena, 67% more aphids were found on control soybean compared with nematode infected plants. No-choice feeding assays were also conducted using clip cages and apterous (flight-incapable) aphids to investigate effect of soybean cyst nematode infection of soybean on aphid performance. These studies had mixed results: in one set of experiments overall aphid population growth at 7 d was not statistically different between control and soybean cyst nematode-infected plants. A different experiment using a life-table analysis found that apterous aphids feeding on soybean cyst nematode-infected plants had significantly greater finite rate of increase (λ), intrinsic rate of increase (r_m), and net reproductive rate (R_o) compared with aphids reared on uninfected (control) soybean plants. We conclude that the below-ground herbivore, soybean cyst nematode, primarily influences soybean aphid behavior rather than performance.

Since its introduction in 2000, the soybean aphid (Aphis glycines Matsumura) has been a serious pest of soybean in North America. Currently, insecticide application is the only recommended control method. However, a number of natural enemies have the potential to regulate soybean aphid populations. In 2007, Aphelinus certus Yasnosh, a soybean aphid parasitoid native to Asia, was found in commercial soybean fields in Ontario. This is the first record of this species in North America. To evaluate the potential biological control services provided by A. certus for soybean aphid management, temperature-dependent developmental parameters and functional response to soybean aphid were determined. A. certus is capable of completing its development between temperatures of 15.3 and 30.2°C. The lower thresholds of development for the egg-mummy and mummy-adult life stages were determined to be 9.1 and 11.6°C, respectively. The lethal temperature of development for the egg-mummy and mummy-adult life stages were 29.5 and 31.0°C, respectively. In this temperature range, A. certus did not exhibit temperature-dependent mortality; however, parasitism rate increased with temperature. A. certus exhibited a type II functional response to the soybean aphid.

Tethered-flight techniques were used to investigate the flight potential of 1-d-old adult beet webworm, Loxostege sticticalis L. (Lepidoptera: Pyralidae), reared at densities of 1, 10, 20, 30, and 40 larvae per 650-ml jar. Larval density had a significant effect on the flight potential, including total flight duration, distance, average velocity, and longest flight duration. Adults reared at a density of 10 larvae per jar, and those reared in isolation displayed the greatest and poorest flight capacity, respectively, relative to the other density treatments. Larval density also significantly affected length of the preoviposition period. Females with longer preoviposition period usually showed greater flight potential, and preoviposition period was positively correlated with flight potential. Rody weight, water content, and triglyceride content of the moths were significantly affected by larval density, whereas glycogen content was not. Triglyceride content of adults reared at the different larval densities corresponded to the observed differences in flight potential, whereas water content and body weight were not related to their flight potential. These results suggest that larval density exerts a significant influence on preoviposition period and triglyceride content, which in turn influence flight potential of adult L. sticticalis.

We compare the efficiencies of different stages of Hippodamia variegata (Coleoptera: Coccinellidae) preying on Aphis fabae (Scolpoli) (Hemiptera: Aphididae) by estimating the functional responses of all stages. The experiments were carried out on leaf disks in petri dishes with 15–20 replicates. Our results revealed that all larval instars and adult males and females of H. variegata exhibited type II functional responses on different densities of prey. The rate of searching efficiency and handling time were estimated as 0.063 h^-1 and 6.933 h for first instar, 0.059 h^-1 and 3.343 h for second instar, 0.103 h^-1 and 1.909 h for third instar, 0.114 h^-1 and 0.455 h for fourth instar, 0.159 h^-1 and 1.194 h for male, 0.093 h^-1 and 0.409 h for female, respectively. Thus, handing time decreased from first instar to female. Handling times of males were significantly greater than those of females. The most effective stages of H. variegata were females, fourth instars, and males. The efficiency of females was nearly three times greater than that of males. The voracity of larval stages and male and female adults of H. variegata were estimated as 2.93, 5.85, 12.13, 45.13, 18.33, and 44.60 (aphids/d), respectively.

Multiple species of Pseudacteon phorid flies (Diptera: Phoridae) are currently being released throughout the southern United States to aid biological control of red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae). It is anticipated that these flies will interfere with S. invicta foraging, allowing native ant assemblages to outcompete S.invicta for available resources. Numerous studies have shown a decrease in S.invicta foraging intensity when exposed to phorids. This study documents a behavioral change in phorid-exposed S.invicta colonies at a phorid release site in central Texas. Significant differences in forager size ratios were detected between phorid-exposed and phorid-absent colonies. A similar phenomenon was recently documented in the native range of these insects in South America as well. Experimental manipulation of ratios of S.invicta worker sizes has been shown to have important effects on colony success. This newly documented phorid-mediated S.invicta colony-level effect represents a significant shift in S.invicta foraging dynamics and may provide an additional mechanism by which phorids can influence S.invicta populations in their United States range.

Coptotermes formosanus Shiraki and C. gestroi (Wasmann) are the most widely distributed species of the genus and occur sympatrically in the subtropics. Results of two bioassays in the current study showed that C. gestroi was more aggressive than C. formosanus. In the petri-dish bioassays, C. gestroi won most of the agonistic encounters over C. formosanus. In the two-dimensional foraging arena bioassays, over 73% tunnel interceptions observed in the 18 replications were caused by progressing tunnels of C. gestroi encountering the tunnels of C. formosanus. Tunnel interception of the two species resulted in minor agonistic interactions. Both species quickly buried the connected tunnel at multiple locations. Termite cadavers resulting from agonistic behavior appeared to have induced sand deposition that resulted in tunnel blockages and deterred reopening of these blockages. Sealing individual tunnels in response to encounters with other species acts to prevent further agonism and mortality, and on a broad scale, the aggregate of such blocked tunnels may come to define the borders between adjacent colonies.

A sampling study using a BG-Sentinel trap baited with CO₂, a gravid trap baited with an oak-pine infusion, a human subject, and a vegetative aspirator was conducted to compare their reliability at detecting Aedes albopictus Skuse in suburban and sylvatic habitats. We collected 73,849 mosquitoes, representing 29 species from 11 genera over a 20-wk period. The BG-Sentinel trap accounted for over 85% of all Ae. albopictus captured and was significantly more effective at detecting the presence of Ae. albopictus compared with the other three techniques. Landing counts provided the fewest mosquito species (n = 10), yet provided a quick and effective weekly assessment of the major biting species and were the most effective method for sampling Ae. albopictus within a 10-min period. Fewer Ae. albopictus were sampled from sylvatic habitats compared with suburban ones. Sampling criteria advantageous for surveying Ae. albopictus and other mosquito species are discussed.

Sampling studies were conducted on grass thrips, Anaphothrips obscurus (Müller) (Thysanoptera: Thripidae), in timothy, Phleum pratense L. These studies were used to compare the occurrence of brachypterous and macropterous thrips across sampling methods, seasons, and time of day. Information about the population dynamics of this thrips was also revealed. Three absolute and two relative methods were tested at three different dates within a season and three different daily times during four harvest periods. Thrips were counted and different phenotypes were recorded from one of the absolute methods. Absolute methods were the most similar to one another over time of day and within seasonal dates. Relative methods varied in assessing thrips population dynamics over time of day and within seasonal dates. Based on thrips collected from the plant and sticky card counts, macropterous individuals increased in the spring and summer. Thrips aerially dispersed in the summer. An absolute method, the beat cup method (rapping timothy inside a plastic cup), was among the least variable sampling methods and was faster than direct observations. These findings parallel other studies, documenting the commonality of diel and diurnal effects on sampled arthropod abundance and the seasonal effects on population abundance and structure. These studies also demonstrate that estimated population abundance can be markedly affected by temporal patterns as well as shifting adult phenotypes.

MultiLure traps were deployed in a Hawaiian orchard to compare the attraction of economically important fruit flies and nontarget insects to the three-component BioLure and torula yeast food lures. Either water or a 20% propylene glycol solution was used to dissolve the torula yeast or as capture fluid in BioLure traps. Torula yeast in water was more attractive than BioLure for male and female Bactrocera Cucurbitae (Coquillett) and Bactrocera dorsalis (Hendel) and as attractive for Ceratitis capitata (Wiedemann), and the addition of propylene glycol significantly inhibited the attractiveness of torula yeast. The known synergistic effect of propylene glycol with BioLure, resulting in increased captures of Anastrepha flies, was not observed with Bactrocera. Nontarget Drosophilidae, Neriidae, Phoridae, Calliphoridae, Sarcophagidae, and Muscidae were more strongly attracted to BioLure, and both lures collected Chloropidae equally. As with fruit flies, propylene glycol in torula yeast significantly decreased nontarget captures. The results therefore suggest that torula yeast in water is a more effective attractant than BioLure for pest Bactrocera while minimizing nontarget captures.

Aulacorthum solani (Kaltenbach) (known as foxglove aphid or glasshouse potato aphid) is a pest of increasing economic importance in several agricultural crops worldwide, including greenhouse vegetables and ornamentals. Developmental rates and age-specific life tables for a North American population of A.solani on pansy (Viola × wittrockiana) (Gams.) were determined at six constant temperatures, and comparisons were made to previous studies of A.solani from differing geographic regions and host crops. On pansy, A. solani developed fastest at 25°C, passing through the four nymphal instars in an average of 6.9 d. The highest intrinsic rates of population increase (0.410 and 0.445) and shortest population doubling times (1.69 and 1.56 d) were recorded at 20 and 25°C, respectively. Average total fecundity remained high from 10 to 20°C (74–68 nymphs/adult); a significant decrease to 39 nymphs/adult occurred at 25°C. For calculating developmental thresholds, we present here a method of adjusting the lower developmental threshold (t_min) using estimates from nonlinear models to provide an improved estimate of the thermal constant (K, in degree-days). We also call attention to the necessity of using a simulation method to estimate the true upper developmental threshold (T_max) and optimum developmental temperature (T_opt) from the Lactin-2 model of temperature-dependent development.

Accurate models of temperature-dependent embryonic developmental rates are important to assess the effects of a changing climate on insect life cycles and to suggest methods of population management by habitat manipulation. Embryonic development determines the life cycle of many species of grasshoppers, which, in cold climates, spend two winters in the egg stage. Increasing temperatures associated with climate change in the subarctic could potentiate a switch to a univoltine life cycle. However, egg hatch could be delayed by maintaining a closed vegetative canopy, which would lower soil temperatures by shading the soil surface. Prediapause and postdiapause embryonic developmental rates were measured in the laboratory over a wide range of temperatures for Melanoplus borealis Fieber and Melanoplus sanguinipes F. (Orthoptera: Acrididae) A model was fit to the data and used to predict dates of egg hatch in the spring and prediapause development in the fall under different temperature regimens. Actual soil temperatures were recorded at several locations over 5 yr. To simulate climate warming, 2, 3, or 4°C was added to each hourly recorded temperature. Results suggest that a 2, 3, or 4°C increase in soil temperatures will result in eggs hatching ≈3, 5, or 7 d earlier, respectively. An increase of 3°C would be required to advance prediapause development enough to allow for a portion of the population to be univoltine in warmer years. To simulate shading, 2 and 4°C were subtracted from observed temperatures. A 4°C decrease in temperatures could potentially delay hatch by 8 d.

The influence of generation (under field conditions) and photoperiod (under laboratory conditions) on Lobesia botrana larvae development was studied. Some larvae were collected during three annual generations in two grape-growing areas of northeastern Italy, and others were individually reared in the laboratory from egg to pupa on an artificial diet under two different photoperiod conditions (respectively, daylight 16 h/d [long day {LD}] and 14 h/d [short day {SD}]). The mandible lengths of collected larvae were measured and the data analyzed morphometrically to determine the number of larval instars. In the laboratory study, the number of larval moultings, the mandible length of each instar, the development time from hatching larva to pupa, and the pupal weight were considered. The measurement of mandible lengths of larvae collected in the field indicated the existence of five larval instars in all three annual generations, but the size of the two oldest larval instars was significantly higher for third-generation larvae than for the previous generations. Under laboratory conditions, the larvae usually exhibited five instars, but the mandible lengths of larvae and the pupa size were greater for individuals reared under SD. These also took a greater number of days to develop from hatching larvae to pupae. Because a larger size of the final larval instar occurs in individuals that produce diapausing pupae under SD in both the laboratory and the field, a positive association between larval size and the probability of surviving the winter can be inferred.

The invasive Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae) has been evident in the North Carolina Piedmont, United States for 90 yr but has failed to spread further north. We investigated the mechanisms preventing this expansion. The Argentine ant ceases foraging at temperatures below 5°C and we hypothesized that winter soil temperatures at higher latitudes restricted foraging long enough to cause colony starvation. We tested if the Argentine ant could successfully feed at temperatures below 5°C and found that colonies would starve. We subjected Argentine ant nests to a range of sub- and above-freezing temperatures and measured worker mortality at various time intervals. We found that Argentine ant colonies will collapse after 8.5 d at 5°C Argentine ants can escape ambient cold temperatures by moving nests into the soil column. We tested how deeply into the soil Argentine ant queens and workers need to move to survive winter in North Carolina. Soil temperatures in the North Carolina Piedmont do not fall below 5°C for longer than nine consecutive days; therefore, Argentine ant colonies need only to retreat a few centimeters into the soil column to escape unsuitable temperatures. Winter soil temperature data from four climate stations situated from latitudes 35°, the current Eastern United States latitudinal limit for Argentine ant population expansion, to 39° were searched for periods where soil temperatures would have led to colony extirpation. North of their current distributions, extended periods of soil temperatures below 5°C regularly occur, preventing Argentine ant colonies from persisting.

Seasonal adaptations to daylength often limit the effective range of insects used in biological control of weeds. The leaf beetle Diorhabda carinulata (Desbrochers) was introduced into North America from Fukang, China (latitude 44° N) to control saltcedars (Tamarix spp.), but failed to establish south of 38° N latitude because of a mismatched critical daylength response for diapause induction. The daylength response caused beetles to enter diapause too early in the season to survive the duration of winter at southern latitudes. Using climate chambers, we characterized the critical daylength response for diapause induction (CDL) in three ecotypes of Diorhabda beetles originating from 36, 38, and 43° N latitudes in Eurasia. In a field experiment, the timing of reproductive diapause and voltinism were compared among ecotypes by rearing the insects on plants in the field. CDL declined with latitude of origin among Diorhabda ecotypes. Moreover, CDL in southern (<39° N latitude) ecotypes was shortened by more than an hour when the insects were reared under a fluctuating 35–15°C thermoperiod than at a constant 25°C. In the northern (>42° N latitude) ecotypes, however, CDL was relatively insensitive to temperature. The southern ecotypes produced up to four generations when reared on plants in the field at sites south of 38° N, whereas northern ecotypes produced only one or two generations. The study reveals latitudinal variation in how Diorhabda ecotypes respond to daylength for diapause induction and how these responses affect insect voltinism across the introduced range.

The effect of temperature on the development, survivorship, fecundity, and life table parameters of Octodonta nipae (Maulik) (Coleoptera: Chrysomelidae), was studied at seven constant temperatures of 17.5, 20, 22.5, 25, 27.5, 30, and 32.5°C. Preliminary experiments showed that no development was observed at 15 and 35°C. All individuals completed development and females laid eggs from 20 to 30°C. There was a significant decrease in male and female longevity with increasing temperatures from 20 to 30°C. The longest and shortest longevity were 203.5 and 73.7 d for males, and 178.7 and 57.6 d for females, respectively. Females produced on average 62.7, 88.9, 116.8, 70.0, and 47.3 eggs and the life expectancy for a newborn egg was 171.6, 148.7, 114.9, 89.2, and 94.8 d at 20, 22.5, 25, 27.5 and 30°C, respectively. Life history data were analyzed by using an age-stage, two-sex life table. The intrinsic rate of increase (r) and the finite rate of increase (λ) of O. nipae increased with increasing temperatures from 20 to 30°C, while the mean generation time (T) decreased within this temperature range. The r was 0.0155, 0.0249, 0.0339, 0.0361, and 0.0383 d^-1 at 20, 22.5, 25, 27.5, and 30°C, respectively. The net reproductive rate (R₀) was highest at 25°C (35.0 offspring), and lowest at 20°C (17.0 offspring). T was shortest at 30°C (76.4 d). The results showed that temperature greatly affected the fecundity and life table parameters of O. nipae, and a suitable temperature for population development and fecundity was at 25°C. The life table data can be used for the projection of population growth and evaluation of control programs.

Contemporary distribution of North American species has been shaped by past glaciation events during the Quaternary period. However, their effects were not as severe in the southern Rocky Mountains and Northern Mexico as elsewhere in North America. In this context, we test hypotheses about the historical demography of Dendroctonus pseudotsugae, based on 136 haplotypes of mitochondrial cytochrome oxidase I. The phylogenetic analysis yielded four haplogroups corresponding to northwestern United States and southwestern Canada (NUS), southwestern United States (Arizona, SUS), northwestern Mexico (Sierra Madre Occidental, SMOC), and northeastern Mexico (Sierra Madre Oriental, SMOR). Predictions of demographic expansion were examined through neutrality tests against population growth and mismatch distribution. Results showed that the NUS and SMOC haplogroups have experienced demographic expansion events, whereas the SUS and SMOR haplogroups have not. Divergence times between pairs of haplogroups were estimated from early to middle Pleistocene. The longer divergence time between NUS and all other haplogroups could be the result of refugia within the Pacific Northwest and northern Rocky Mountains and long-term isolation from southernmost populations in Mexico. The results obtained in this study are in agreement with the evolutionary history of the host Douglas-fir, as the warmer climates of interglacial periods pushed conifers northward of Colorado, New Mexico, and Arizona, whereas environmental changes reduced the population size of Douglas-fir and forced fragmentation of distribution range southward into northern Mexico.

Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a key insect pest of cotton in Xinjiang cotton-planting region of northwest China. In this region, cotton is grown on average ∼1.65 million ha (1.53∼1.80 million ha) annually in largely monoculture agricultural landscapes, similarly to cropping systems in the United States or Australia. Under such cropping regimes, naturally occurring refuges (with non-Bt crops) may be insufficient to prevent H. armigera resistance development to Bt toxins. Therefore, we assessed frequency of alleles conferring resistance to Cry1Ac toxin of F₁ and F₂ offspring of H. armigera isofemale lines from two distinct localities in the region during 2005–2009. More specifically, a total of 224 isofemale lines was collected from Korla County (≈70% Bt cotton adoption) and 402 lines from Shache County (≈5% Bt cotton planting). Subsequent offspring was screened on Cry1Ac artificial diet. From 2005 to 2009, resistance gene frequency in Korla fluctuated between 0.0000 and 0.0040, while being 0.0000-0.0008 in individuals collected from Shache, and there were no significant increases in both counties from 2005 to 2009. Relative average development rates (RADRs) of larvae in F₁ tests showed significant increases from Korla, but not in Shache. RADR of F₁ larvae is significantly correlated with RADR of F₂ offspring, indicating genetic variation in response to toxin in field H. armigera population. Although the occurrence of Cry1Ac resistance alleles was low in Xinjiang cotton-planting region of China, particular attention should be given to H. armigera resistance development in Korla County.