The temporal and small-scale spatial patterns of infestation by larval dogwood borer, Synanthedon scitula (Harris) were studied from 2002 to 2004 in two newly planted apple orchards in West Virginia and Virginia. Rootstock, tree variety, and cultural management practice were significantly associated with the presence and extent of dogwood borer infestation. In West Virginia, infestation was significantly greater on trees planted on M.26 rootstock compared with M.7 rootstock, and on trees fitted with tree guards compared with other trunk treatments. In Virginia, the proportion of infested trees was significantly greater for ‘Idared’ tree varieties compared with ‘Buckeye Gala’, and on trees fitted with tree guards compared with other trunk treatments. Median polishing technique was used to separate variability in the infestation data into large-scale variation (trend) induced mainly by treatments and small-scale variation. Variography was used to study the median-polished residuals of infestation that represent the small-scale variation. The results of variogram analysis of the median-polished residuals indicated that there were moderate to high degrees of aggregation in dogwood borer infestations on neighboring apple trees (Malus domestica Borkh.) with ranges of spatial autocorrelation from 2.8 to 17.0 m. The spatial patterns of the aggregation of infestation in the West Virginia and Virginia orchards were best described by the spherical and exponential semiovariogram models, respectively. Interpolated surface maps of the median-polished residuals revealed local hot spots, which were generally more prevalent within tree guard treatments, and were typically found where dogwood borer infestations originated. Results are discussed in relation to the sampling and management of dogwood borer larvae.

The temporal and spatial patterns of adult stable fly, Stomoxys calcitrans (L.), emergence from six sites where large round baled hay had been provided to pasture cattle as winter feed were studied using emergence traps. The substrate at these sites, consisting of waste hay mixed with bovine manure and urine, provided an excellent developmental habitat for immature stable flies. Stable flies were the most frequently collected fly emerging from these sites with a yearly average of 1,581 emerging per square meter. Stable fly emergence from these sites began in early May (235 annual accumulated Day-Degree 10^°C [DD₁₀]), peaked in late June and early July (400–900 DD₁₀) and then dropped to very low levels in late July (>900 DD₁₀). The temporal pattern of stable fly emergence from the hay feeding sites differed from that of adult populations measured with sticky traps. Adult populations increased in the spring before significant emergence from the hay feeding sites was observed, dipped in midsummer soon after the hay feeding sites became nonproductive, and then rebounded in the late summer when emergence from the hay feeding sites was very low. The drop in productivity of the hay feeding sites appeared to be because of endogenous factors associated with decomposition of the substrate rather than temperature or precipitation. Winter hay feeding sites appear to be primary sources of stable flies during the early summer, however, they are not responsible for late summer and fall stable fly populations. Overall, the inner most 2-m annulus of the hay feeding sites was the most productive, however, spatial variation among sites was observed. The sex ratio of emerging flies did not differ from 1:1 and the temporal pattern of emergence was similar for males and females. Although several other species of flies were collected emerging from the hay feeding site substrate, house flies (Musca domestica L.) were notably absent.

Onion thrips, Thrips tabaci Lindeman, is a key foliage-feeding pest of onion worldwide and the principal vector of a serious onion pathogen, Iris yellow spot virus (IYSV). Long-term management of T. tabaci and IYSV will require an understanding of T. tabaci ecology and IYSV epidemiology in onion ecosystems. This study focused on identifying winter-annual, biennial and perennial weed species that host both T. tabaci and IYSV. Unlike summer-annual weeds, weeds with these habits survive overwinter and could serve as a green bridge for IYSV to survive between onion-growing seasons. T. tabaci larvae and adults were sampled every two weeks from 69 weed species in five areas located adjacent to onion fields in western New York in 2008 and 2009. Twenty-five of the 69 weed species were identified as hosts for T. tabaci larvae and populations were highest on the Brassicaceous weeds, Barbarea vulgaris Ait. f., Sinapis arvensis L., and Thalspi arvense L. None of these species are hosts for IYSV. Four of the 25 weed species were hosts for both T. tabaci larval populations and IYSV: common burdock, Arctium minus Bernh., dandelion, Taraxacum officinale G.H. Weber ex Wiggers, curly dock, Rumex crispus L., and chicory, Cichorium intybus L. Of these four weed species, T. officinale and A. minus may play an important role in the epidemiology of IYSV in New York onion fields because they may survive between onion-growing seasons, they are relatively abundant in the landscape, and they support relatively high densities of T. tabaci.

We investigated the effect of broad-scale wildfire on ground foraging ants within southern California. In October and November of 2003, two wildfires burned large portions of the wildlands within San Diego County. Between January 2005 and September 2006, we surveyed 63 plots across four sites to measure the effect of the fires on the ant assemblages present in four vegetation types: 1) coastal sage scrub, 2) chaparral, 3) grassland, and 4) woodland riparian. Thirty-six of the 63 plots were sampled before the fires between March 2001 and June 2003. Mixed model regression analyses, accounting for the burn history of each plot and our pre- and postfire sampling efforts, revealed that fire had a negative effect on ant species diversity. Multivariate analyses showed that ant community structure varied significantly among the four vegetation types, and only the ant assemblage associated with coastal sage scrub exhibited a significant difference between burned and unburned samples. The most notable change detected at the individual species level involved Messor andrei (Mayr), which increased from <1% of prefire coastal sage scrub ant samples to 32.1% in burned plots postfire. We theorize that M. andrei responded to the increase of bare ground and postfire seed production, leading to an increase in the detection rate for this species. Collectively, our results suggest that wildfires can have short-term impacts on the diversity and community structure of ground foraging ants in coastal sage scrub. We discuss these findings in relation to management implications and directions for future research.

Leafminer flies (Diptera: Agromyzidae) are important agricultural pests worldwide. The objective of our study was to assess the relative importance of agromyzids and their associated parasitoids in field and vegetable crops along the Peruvian coast. In total, nine leafminer fly species were identified in 27 crops. The most dominant species was Liriomyza huidobrensis (Blanchard) (88.0%). Liriomyza sativae Blanchard was the second most dominant species (8.59%) but mainly found in the most northern part of Peru. On average, a parasitism of 29.5% was registered by 63 parasitoids belonging to the families Eulophidae (41 spp.), Braconidae (11 spp.), Pteromalidae (8 sp.), Fitigidae (1 sp.), and Mymaridae (2 spp.). The endoparasitoids Halticoptera arduine (Walter) (48.2%), Chrysocharis flacilla Walker (19.5%), and C. caribea Boucek (8.0%) as well as the ectoparasitoid Diglyphus websteri (Crawford) (8.7%) were the most abundant parasitoids. H. arduine was not only the most abundant and efficient parasitoid but also parasitized all leafminer fly species in 25 crops. The wide adaptation of the parasitoids H. arduine, C. flacilla, C. caribea, D. websteri, D. begini, and Ganaspidium Weld sp. to different host plants and leafminer fly species indicates the potential use of those parasitoids for biological control programs. The high diversity of parasitoids supports the assumption that leafminer flies are of neotropical origin. The heavily pesticide-based pest management practices along the Peruvian coast should take more advantage of the richness of parasitoids by augmenting its efficacy through the adoption of integrated pest management.

The introduction of an invasive species into an agroecosystem can alter both the interspecies dynamics and existing management practices. In the area of introduction, seasonality of Halyomorpha halys (Stål) in soybean fields was investigated by comparing monitoring efficiency of sweep net sampling and two sizes of pyramid traps baited with aggregation compound methyl (E,E,Z) 2,4,6-decatrienoate in 2006–2007. The large pyramid trap caught significantly higher densities of H. halys than the small pyramid trap and the sweep net samples each year. Adult males and females were detected in significantly higher densities in the large pyramid trap than other life stages. The pyramid traps caught H. halys adults and nymphs earlier than sweep net samples, during the R3 and R4 phenological stages of soybean growth. Peak abundances in the pyramid traps occurred during the R5–R6 stages, while the sweep samples were highest during the R6 stage. Soybean is sensitive to stink bug feeding damage from the R3–R6 stages. The occurrence of H. halys in soybean coincides with soybean's critical growth stage. H. halys has become the dominant stink bug species in the crop, indicating that damage thresholds need to be determined.

Many studies have analyzed the effect of forest fragmentation on dung beetle diversity in tropical landscapes. Few of them, however, have analyzed how forest fragmentation affects the assemblage structure of necrophagous beetles and their removal rates of carrion in tropical forests. This study compares the effect of the time of the day in which carrion is offered to dung beetles (in the morning or at night) on the rates of carrion removal over time (12, 24, and 36 h) in tropical rain forest fragments of different sizes. Fragment size, time, and carrion offer had no effect on carrion removal rates in this study, but these factors affected abundance and species richness of necrophagous beetles. Carrion removal was the highest 12 h after the carrion had been offered. The average rate per hour of carrion removal in all fragments after 12 h was 4.47 g/h, after 24 h was 3.27 g/h, and 36 h later 2.64 g/ h. Carrion removal rates are likely to be affected by beetle abundance and species richness. The most abundant species captured when carrion was offered at night was Coprophanaeus telamon Harold, a nocturnal necrophagous tunneler beetle. When carrion was offered in the morning, the most abundant species was the diurnal copro-necrophagous roller beetle Canthon cyanellus LeConte. Large nocturnal tunneler beetles were only found in large fragments, but small diurnal roller species were abundant in both large and small fragments. Our results suggest that different species contribute unevenly in different ways to carrion removal in tropical forest fragments. Carrion removal is not affected by fragment size per se, but by the fragmentation process.

When a crop is introduced into a new region the herbivorous insect communities are structured from the regional pool of species, and the spatio—temporal heterogeneity of the landscape and the spatial arrangement of habitat elements are essential for species diversity. The blueberry, Vaccinium corymbosum L., is a crop native to the northern hemisphere and was introduced in Argentina in the 1990s. We have analyzed the richness and diversity of insect herbivore communities in several blueberry crops located in different agricultural landscapes of Buenos Aires and Entre Ríos, in Argentina. In total, the number of families recorded throughout the study period was 31. The richness and the diversity showed significant differences among phenological stages and years, although the sites had an effect on the richness, in Buenos Aires. Aphidae was the most abundant family in all sites, followed by different families depending on the surrounding crops and their more common herbivores. The highest values of cumulative alpha diversity were in crops located in more changing landscapes. There were high values of temporal beta diversity everywhere. Spatial beta diversity was higher in Buenos Aires than in Entre Ríos, probably because the crops of the latter are located in similar landscapes. Gamma diversity was 29 families for communities of Buenos Aires and it was 15 families in Entre Ríos. The herbivorous communities in blueberry crops of Argentina are shaped by ectophagous generalist (South American and cosmopolitan) from the regional pool of species, characteristic of the landscape where the crops were introduced.

The soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae) is an invasive economic pest of soybean (Glycine max [L.] Merrill) in the United States. Research has shown the endemic natural enemy community in the United States is capable of suppressing A. glycines below EILs, but this biological control is inconsistent, especially in simple agricultural landscapes. In the course of a 3-yr project (2006–2008) we sought to determine the affects of landscape composition, configuration, and plant nutrients (N, P, and K) on A. glycines and aphidophagous natural enemy abundance. Specifically, we tested whether nearby grasslands contribute to the abundance of natural enemies and the suppression of A. glycines. The study site was located around the Neal Smith National Wildlife Refuge, composed of >2,000 ha of reconstructed prairie, located in Jasper County, IA. We sampled A. glycines, natural enemies, and plant nutrients in 100 soybean fields while characterizing the landscape surrounding each field. A. glycines abundance was lowest in 2006 but reached economically damaging populations in 2007 and 2008. The ratio of natural enemies to A. glycines decreased in each year of our study (2006 > 2007 > 2008). Variation in A. glycines and natural enemies was best explained by year and, to a lesser extent by plant nutrient levels and landscape variables. Results suggest grassland habitat did not significantly contribute to the biological control of A. glycines. Furthermore, yearly decline of natural enemy may have facilitated the colonization of A. glycines leading to outbreaks later in the season.

The southern pine beetle (Dendroctonus frontalis Zimmermann, Coleoptera: Curculionidae) is the most destructive insect in southern forests. States have kept county-level records on the locations of beetle outbreaks for the past 50 yr. This study determined how accurately patterns of county-level infestations in preceding years could predict infestation o ccurrence in the current year and if there were emergent patterns that correlated strongly with beetle outbreaks. A variety of methods were tested as infestation predictors, including quantification of either the exact locations of infested grid cells during one or two preceding years, or the neighborhood infestation intensity (number of infested cells in a neighborhood) in these years. The methods had similar predictive abilities, but the simpler methods performed somewhat better than the more complex ones. The factors most correlated with infestations in future years were infestation in the current year and the number of surrounding counties that were infested. Infestation history helped to predict the probability of future infestations in a region, but county-level patterns alone left much of the year-to-year variability unexplained.

A survey of stag beetle (Lucanidae)-associated nematodes was conducted in Japan to construct a preliminary species inventory and to obtain their molecular profiles as a first step for elucidating their host fidelity and ecological roles. Eight species of stag beetles (94 individuals in total), Dorcus rubrofemoratus, D. montivagus, D. striatipennis, D. rectus, D. titanus, Prismognathus angularis, Prosopocoilus inclinatus, and Lucanus maculifemoratus were collected from 12 localities in Japan, dissected and examined for nematode associates. Isolated nematodes were used to attempt the establishment of voucher cultures. Successfully cultured nematodes were observed under a light microscope for morphological identification at genus or species level, and were sequenced for their near full length SSU and D2/D3 LSU. All investigated lucanid individuals harbored at least one species of nematode, and eight species (Bursaphelenchus sp., Koerneria luziae, K. lucani, Pristionchus cf. pacificus, Pristionchus sp., Pseudodiplogasteroides composites, Pseudodiplogasteroides sp., and Rhabditidoides sp.: 40 populations of nematodes in total), were successfully cultured from the insects. Within these eight species, four species were considered to predominate and had low carrier specificity and wide distribution, i.e., K. luziae, P. composites, Pristionchus sp. and Rhabditidoides sp. were isolated from various species of beetles and from several different localities, and K. luziae, K. lucani, and P. composites have been previously described from native lucanids in Germany. Considering the recent world-wide trade of living insects, especially lucanids as pets, we suggest the use of caution to prevent the invasion of their associated nematodes and other associated organisms.

Symbioses are major drivers in ecology and evolution. Although nearly omnipresent in flowing waters, they remain poorly studied in these systems. To examine fundamental aspects of the ecology of symbioses in flowing-water systems, we use larval black flies as hosts and various fungi, nematodes, and protists as symbiotes, focusing on aspects of distribution, diversity, and scale. Most symbiotes of larval black flies are considered parasitic, although the dynamic nature of the relationship is becoming apparent for some systems in which it shifts along a continuum involving commensalism, mutualism, and parasitism. Perspective also is moving from a pairwise view of symbiotic associations to a multispecies network of interactions. Distributions of symbiotes are related to scale-dependent processes that influence the hosts and the stream habitats of the hosts; thus, characteristics of streams, as well as hosts, can be useful in predicting spatial patterns of symbiotes. As the taxonomy of symbiotes improves, so too does the understanding of ecological relationships of symbiosis, such as host specificity and patterns of diversity along spatial and temporal scales.

In southeastern United States farmscapes, corn, peanut, and cotton fields are often closely associated with each other. Thus, this 5-yr study was conducted to determine parasitism and predation of sentinel and natural occurring Euschistus servus (Say) and Nezara viridula (L.) egg masses in farmscapes in Georgia. A variety of parasitoids including six scelionids, Trissolcus basalis (Wollaston), T. brochymenae (Ashmead), T. euschisti (Ashmead), T. thyantae Ashmead, Telenomus podisi Ashmead, and Gyron obesum Masner, and one encyrtid, Ooencyrtus spp., was recovered from E. servus and N. viridula eggs, but overall the greatest diversity of parasitoids emerged from stink bug eggs in corn. Only T. basalis and T. podisi parasitized both N. viridula and E. servus eggs in all three crops over all farmscapes. A wide variety of predators, including Orius insidiosus (Say), Geocoris punctipes (Say), G. uliginosus (Say), Coccinella septempunctata (L.), Hippodamia convergens Guérin-Méneville, Harmonia axyridis (Pallas), Coleomegilla maculata (De Geer), Scymnus loewii Mulsant, Scymnus ardelio Horn, and Solenopsis invicta Buren, preyed on stink bug eggs in each crop. When differences were detected, generally percent parasitization per egg mass was higher than predation in corn, and percent predation was higher than parasitization in peanut. Overall, percent predation per egg mass was higher than parasitization in cotton, but on one occasion percent parasitization was higher than predation in cotton associated with corn. Seasonal occurrence and abundance of natural enemies, levels of parasitization and predation of stink bug eggs, and percent egg predation by sucking and chewing predators indicated that natural enemies of stink bug eggs disperses from crop to crop in the farmscapes. Stink bug egg predators and parasitoids are likely responding to host plant switching by their prey or hosts. In conclusion, this study has shown that natural enemies of stink bugs are prevalent and important biological control agents in these farmscapes.

The larval parasitoid, Psyttalia humilis (Silvestri), reared on Mediterranean fruit fly, Ceratitis capitata (Weidemann), by USD A-APHIS-PPQ, San Miguel Petapa, Guatemala was imported into California for biological control of olive fruit fly, Bactrocera oleae (Rossi). This study reports the results of field releases and recovery of P. humilis in California, and laboratory investigations to determine the effects of food provision, high temperature, and insecticidal bait spray on the parasitoid's survival and fecundity. Parasitoids (3,613–7,823) were released in Orland, San Juan Bautista, Cayucos, Sylmar, Santa Barbara, and San Diego during October through December 2006. Mean daily temperatures at the release sites ranged from 10.7°C in Orland to 20.9°C in San Juan Bautista. The lowest (0.5) and highest (29.7) mean number of adult B. oleae per day per trap was captured in Orland and Sylmar, while the lowest (0.01) and highest (2.21) number of third instar larvae per fruit was collected on 11 December in Orland and on 5 October in San Diego in prerelease samples, respectively. Parasitoids were recovered from all release sites, the lowest (0.3%) and highest (100%) parasitism occurred on 25 January in Sylmar and on 26 October in Cayucos, respectively. At 24°C, parasitoids reared from B. oleae larvae survived 36 d on honey, 31 d on orange juice, and 28 d on honeydew, which was significantly longer than on cut olive fruit (8 d) or without food (11 d), but was similar to those reared from C. capitata larvae under the same food conditions. Under a high diurnal temperature regime (18.3–35°C) reflecting the summer olive growing conditions in the California Central Valley, the parasitoids survived <5 d when no food or only water was provided. Its longevity and life-time fecundity significantly increased by provision of honey or honeydew. There was no difference in the parasitoid's longevity between females and males or between food and sexes. Percent mortality of parasitoid adults was not significantly affected by the exposure to insecticidal fruit fly bait (GF-120) in four different types of choice tests with artificial honeydew and GF-120.

Hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is an invasive pest of eastern hemlock (Tsuga canadensis (L.) Carrière) and Carolina hemlock (T. caroliniana Englem.) in eastern United States. Host-range tests for Laricobius osakensis Montgomery and Shiyake (Coleoptera: Derodontidae), imported from Japan, were conducted under quarantine in Blacksburg, VA, to determine the suitability of this predator as a biological control agent of A. tsugae. Host-range testing for L. osakensis, involved no-choice and paired choice feeding, oviposition, and development tests with A. tsugae, three other adelgids, and three nonadelgid species. L. osakensis fed and laid more eggs on A. tsugae over all the other host species. The difference was greater in paired-choice tests. L. osakensis completed development only on A. tsugae. The overall results of the host range study indicate that L. osakensis is a specific predator of A. tsugae, supporting its potential as a biological control agent, and is not a threat to nontarget species populations.

The diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae) is a serious pest of economically important brassica crops such as cabbage (Brassica oleracea Linne). To address the current lack of baseline information concerning predators of P. xylostella, and their potential role as biological control agents, especially in Central America, we aimed to 1) identify predators in northern Nicaragua, and estimate their population densities; 2) assess their killing rate of eggs and larvae of P. xylostella; and 3) assess if predators feed more of smaller P. xylostella larvae. Individuals of selected predator groups were offered eggs, second- or third-instar larvae. Our results indicate that there exists a broad spectrum of predators, within and around cabbage fields in Nicaragua that have the capacity to feed on P. xylostella eggs and larvae under laboratory conditions. Predators with the highest killing rates were adult and larval rove beetles (Staphylinidae), sheet weaving spiders (Linyphiidae), and larger jumping spiders (Salticidae). Although all predator densities varied in space and time the consistently most abundant predator groups with the highest consumption or killing rate, and consequently the highest potential for suppressing P. xylostella populations were wolf spiders (Lycosidae) and rove beetles (Staphylinidae), although sheet weaving spiders, jumping spiders, assassin bugs (Reduviidae), and damsel bugs (Nabidae) also can be important. We conclude that those generalist predators exhibiting the highest killing rates in the laboratory should be considered for further study in the field as candidate species with a role in the management of pest P. xylostella.

Leaf-cutter ants (Acromyrmex and Atta spp.) exhibit ancient and complex interactions with the symbiotic fungus Leucoagaricus (Basidiomycetes: Agaricales) from which they feed, and with the virulent and specific fungus Escovopsis weberi J.J. Muchovej & Delia Lucia (Ascomycetes: Hypocreales) that attacks the ants' fungal gardens. This system offers a unique opportunity to study possible avenues for replacing polluting pesticides with a biological control agent against the ants. We isolated both Leucoagaricus sp. and E. weberi from the gardens of Acromyrmex lundii Guérin-Méneville colonies and confronted them with each other by growing Leucoagaricus on petri dishes and placing inoculated pieces of agar inoculated with E. weberi at the edges. Here we present growth curves of Leucoagaricus sp. and E. weberi in the absence of each other, as a baseline to which we compare the effect of the fungi on each other. As expected, we found a negative effect of E. weberi on the ant cultivar from different colonies of A. lundii. E. weberi increased its growth rate, as well as the levels of conidiation, in the presence of the ant cultivar. We determined that a soluble and diffusible compound, released by the cultivar, triggered, was responsible for, or did both for the increased levels of conidiation in E. weberi, and that this response was reversible. We discuss why our results are encouraging from a biological control perspective.

The potato aphid, Macrosiphum euphorbiae (Thomas), (Homoptera: Aphididae), is a polyphagous aphid known to feed on over 200 plant species across 20 families. Although this aphid is known as one of the potato (Solanum tuberosum L.) colonizing aphids, field observations for populations of M. euphorbiae in southern Idaho indicated that they preferentially settled and colonized hairy nightshade, Solanum sarrachoides (Sendtner), plants rather than potato plants. Laboratory investigations revealed that M. euphorbiae survived only on S. sarrachoides and not on potato. A series of subsequent laboratory experiments conducted using laboratory-reared and field-collected aphids confirmed that M. euphorbiae survived only on S. sarrachoides. Experiments also showed that M. euphorbiae produced more winged morphs (alatae) than Myzus persicae on S. sarrachoides when reared alone under similar conditions. Furthermore, we documented intraguild competition between M. euphorbiae and M. persicae on S. sarrachoides. Results suggested that M. euphorbiae can potentially suppress M. persicae on S. sarrachoides. Competition studies reiterated that M. euphorbiae produced more alatae than M. persicae. Results also indicated that M. euphorbiae may have specialized on S. sarrachoides. The loss of polyphagous abilities of this M. euphorbiae “biotype” is intriguing and the factors responsible for specialized host utilization pattern remain to be elucidated.

Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), a phloem-feeding beetle native to East Asia, was first discovered in southeast Michigan and Essex County, Ontario, in June 2002 and has since killed millions of ash (Fraxinus spp.) trees in North America. Initial studies in southeast Michigan indicated that the life cycle of A. planipennis was univoltine but more recent observations indicated some larvae feed for two summers, resulting in a 2-yr life cycle. Understanding factors that affect A. planipennis attraction to and development on host trees could improve detection and predictions of its population dynamics. We assessed adult A. planipennis attraction and larval density, distribution, and development rates in 2006 and 2007 on pole-sized green ash (Fraxinus pennsylvanica Marshall) trees that were girdled, exposed to the stress-elicitor methyl jasmonate, or left untreated. The study was conducted in a homogenous plantation with low levels of infestation. Overall, adult captures increased fivefold and four times as many larvae were recorded in 2007 compared with 2006. In both years, girdled trees captured significantly more adult A. planipennis, had higher larval densities, and larvae developed faster than on untreated control trees or trees exposed to methyl jasmonate. In 2006, larvae feeding below the girdle developed significantly faster than larvae feeding above the girdle. Adult A. planipennis captures, larval density and development did not differ significantly between untreated trees and trees exposed to methyl jasmonate in either year.

Lygus hesperus Knight (Hemiptera: Miridae) is a key pest of cotton (Gossypium spp.) in the western United States that injures floral buds (squares) and developing fruit (bolls). Levels of Lygus-induced damage to cotton can vary by Lygus ages or gender, and these variations complicate interpretation of studies designed to elucidate Lygus and cotton interactions. Variations in observed injury may reflect different behaviors among Lygus gender or ages. We compared times allocated to feeding and trivial movement between male and female adult L. hesperus of different reproductive states: prereproductive, reproductive and mated, and reproductive and unmated. Prereproductive adults exhibited less trivial movement and spent more time stylet-probing compared with reproductive unmated and mated adults. Mated females stylet-probed more times than other classes of adults, whereas mated and unmated reproductive females exhibited more test probes (≤10 s duration) than prereproductive females. Reproductive females probed the anther region of squares less than prereproductive females. Instead, reproductive females tended to stylet-probe squares below the bracts, which is also where they oviposited. Each oviposition event was preceded by a short duration stylet-probe at the oviposition location. Unmated reproductive males exhibited more test probes but fewer ingestion probes (>1 min) compared with prereproductive and mated males. These results indicate a pattern in which prereproductive adults are less active and feed more compared with reproductive adults, but behaviors vary among reproductive adults of different gender and mating states. We propose that differences in behaviors exhibited among adult L. hesperus are related to the different requirements imposed by mate seeking, mate attraction, and oviposition.

Concern over the status of bees has increased the need to inventory bee communities and, consequently, has increased the need to understand effectiveness of different bee sampling methods. We sampled bees using bowl traps and netting at 25 northwest Indiana sites ranging from open grasslands to forests. Assemblages of bees captured in bowl traps and by netting were very similar, but this similarity was driven by similar relative abundances of commonly captured species. Less common species were often not shared between collection methods (bowls, netting) and only about half of the species were shared between methods. About one-quarter of species were more often captured by one of the two collection methods. Rapid accumulation of species was aided by sampling at temporal and habitat extremes. In particular, collecting samples early and late in the adult flight season and in open and forest habitats was effective in capturing the most species with the fewest samples. The number of samples estimated necessary to achieve a complete inventory using bowls and netting together was high. For example, ≈72% of species estimated capturable in bowls were captured among the 3,159 bees collected in bowls in this study, but ≈30,000–35,000 additional bees would need to be collected to achieve a 100% complete inventory. For bowl trapping, increasing the number of sampling dates or sampling sites was more effective than adding more bowls per sampling date in completing the inventory with the fewest specimens collected.

Accurate assessments of thrips density are important for effective thrips management programs. Complicating the development of sampling plans for western flower thrips (WFT) Frankliniella occidentalis (Pergande) in greenhouse crops are the facts that they are small, difficult to detect, and attack a variety of crops, which may be grown concurrently within the same greenhouse. Binomial sampling was evaluated as an alternative to sampling plans based on complete enumeration. This work included comparison of incidence-mean models across diverse plant species (impatiens, cucumber, and marigold) to determine the possibility of using a generic model for sampling WFT in mixed crops. Data from laboratory-processed flower samples revealed that infestation rates calculated using a tally threshold of three thrips per flower provided the best estimates of thrips population densities in each tested crop and in the combined crops (composite data set). Distributions of thrips populations were similar across the three plant species, indicating potential for development of a generic sampling plan for mixed floral crops. Practical sampling methods for simple and complex flowers tested in the greenhouse (in situ) were evaluated via construction of binomial count operating characteristic functions. In the case of simple flowers (impatiens), visual inspections provided adequate estimates of thrips infestation rates at a low tally threshold, which ultimately enabled accurate estimation of thrips densities. However, visual inspection and tap-sampling of complex flowers (marigold) provided unreliable results. These findings indicate that use of binomial sampling methods in mixed floral crops will require development of more accurate sampling techniques.

The use of plant diversification (e.g., mixed cropping, cover crops, border plants, intercrops, etc. ) to protect a primary crop from insect transmitted viral diseases is often referred to as barrier cropping. Specific plants used to mitigate virus incidence in a cash crop are frequently called protector plants. The potential use of protector plants to reduce the density of aphid vectors and incidence of aphid-borne nonpersistent virus in zucchini, Cucurbita pepo L. was evaluated during 2003, 2005, and 2006 on Oahu, HI. Cover crops, buckwheat Fagopyrum esculentum Moench and white clover Trifolium repens L., or sunn hemp, Crotolaria juncea L. and an intercropped vegetable, okra Abelmonchus esculentus (L.), were evaluated for their potential use as protector plants. Results of the field experiments showed that densities of alatae aphids in water pan traps did not differ significantly among treatment habitats during three field experiments. However, the percentage of zucchini plants showing virus symptoms was significantly lower in diculture than monoculture habitat during all 3 yr. Results from field and laboratory experiments support the hypothesis that protector plants reduced the incidence of Papaya ringspot virus-watermelon strain by acting as virus sinks and that the three cover crops were more effective in reducing Papaya ringspot virus-watermelon spread than okra.

The olfactory and contact behavioral responses of clover root borer, Hylastinus obscurus (Marsham) (Coleoptera: Curculionidae), against fatty acid components present in 9-mo-old red clover, Trifolium pratense L., roots were investigated by using an automated behavioral observation system. From GC-MS analysis of dichloromethane extracts of T. pratense roots, of 15 compounds identified in total, four long-chain free fatty acids lauric, palmitic, oleic, and stearic acids were found to be main components in the extracts. In a four-arm olfactometer the clover root extract significantly attracted both male and female H. obscurus. When solutions of the four individual synthetic fatty acids and their blend at the ratio found in the root extract (10 µg/ml) were assayed with H. obscurus, lauric, palmitic, and oleic acid elicited an attractant behavioral response from females, whereas all substances tested did not elicit a response from males. In contact bioassays, wood dummies coated with root extract, the four fatty acids, or their respective blend of the same composition found in the root extract at 100 µg/ ml, were significantly preferred by female H. obscurus. In contrast, males showed preference only for dummies treated with root extract, or palmitic or oleic acid. The behavioral evidences suggest that long-chain free fatty acids present in 9-mo-old red clover roots may play a role as close-range olfactory, tactile cues, or both in the host-finding process of H. obscurus.

In some insect species, the presence of a mate at the time of eclosion appears to facilitate rapid mating, with positive fitness consequences for one or both mates. Field observations that males of the hymenopteran parasitoid Pimpla disparis Viereck aggregated on a gypsy moth, Lymantria dispar (L.), host pupa before the emergence of a female led us to hypothesize that these males responded to chemical cues associated with parasitized host pupae. Results of laboratory experiments with wax moth, Galleria mellonella (L.), host pupae suggest that female P. disparis chemically mark the host pupae they have parasitized and that males discern between such pupae and those not parasitized. As males continue to recognize parasitized host pupae throughout the development of the parasitoid, they could exploit not only the females' marker pheromone but possibly also semiochemical, visual, or vibratory cues from the developing parasitoid inside the host pupa, the decaying host, or both. Irrespective, these cues could help males locate parasitized host pupae and time the emergence of a prospective mate.

Listronotus maculicollis Kirby is a highly destructive pest of low mown, cool-season turfgrasses in the northeastern United States and Canada. Behavioral and electrophysiological assays were conducted to identify compounds that may be useful in developing novel monitoring techniques. In Y-tube assays, males and females responded differently to volatiles from intact and clipped annual bluegrass (Poa annua L.). Females were significantly attracted to intact P. annua but repelled from clippings; males did not respond significantly to either treatment. Electroantennogram (EAG) recordings from both sexes showed a significant response to volatiles from both treatments. Gas chromatography mass spectrometry (GC-MS) identified 12 volatile compounds from P. annua of which nine were common to both intact plants and clippings. On average, seven-fold higher quantities of volatiles were collected from clippings than from intact plants (24.3 versus 3.4 ng/g of tissue/h). Eight compounds were released in significantly greater quantities from clippings of which 50% were the n-C₆ compounds hexanal, (E)-2-hexenal, and (Z)-3-hexenyl acetate, commonly referred to as “green leaf volatiles” (GLVs). Only octanal was emitted in greater amounts from intact plants than clippings. These nine compounds were tested individually against male and female antennae. Both sexes displayed greatest sensitivity to nonanal, octanal, and (E)-2-hexenal, but a significant doseresponse relationship was observed with all compounds tested. These studies indicate that both sexes respond physiologically and that L. maculicollis females exhibit behavioral responses to host-plant volatiles. Future studies will need to assess the effects of individual compounds and component mixtures on L. maculicollis behavior in the field.

Laboratory and field studies were conducted to measure the responses of adult codling moth, Cydia pomonella (L.), to several plant volatiles presented alone and in combination with acetic acid. Plant volatiles included ethyl (E,Z)-2,4-decadienoate (pear ester), (E)-β-farnesene, (Z)-3-hexenyl acetate, ± farnesol, and (E)-4,8-dimethyl-l,3,7-nonatriene (DMNT). Male codling moth exhibited upwind behavioral responses to each compound in flight tunnel tests with acetic acid > DMNT > ± farnesol > (Z)-3-hexenyl acetate > pear ester > (E)-β-farnesene. In apple orchards, however, only pear ester was an effective lure when used alone with clear pane traps. Choice tests in a flight tunnel with delta traps baited with DMNT plus acetic acid caught significantly more male and females than unbaited traps and significantly more females than DMNT-baited traps. Combining pear ester or DMNT loaded in septa lures with separate vials containing acetic acid significantly increased both male and female moth catch compared with the plant volatile alone, acetic acid alone, and unbaited pane traps in field trials. Similar results were not obtained with the other three plant volatiles. Septum loadings of 1 and 10 mg with either pear ester or DMNT in combination with acetic acid caught similar numbers of moths in orange delta traps. Sixty to 75% of the moths captured in traps baited with DMNT plus acetic acid were females. Moth catches in traps baited with DMNT plus acetic acid were ≈40% of catches in similar traps baited with pear ester plus acetic acid.

We assessed the life history parameters and temperature requirement of a Korean population of the endoparasitoid Aphelinus asychis Walker (Hymenoptera: Aphelinidae), using Aphis gossypii Glover (Hemiptera: Aphididae) as a host. We first measured the time from egg to mummification (i.e., pupation) and mummification to adult emergence (i.e., pupal period) at 25°C. The pupal period was significantly longer than the egg to pupation period in both genders, unlike in other regional populations of the species. Females produced an average of 342.9 mummies, he highest reported fecundity among the various regional populations of this species. Age-specific realized fecundity peaked between the 4th and 7th day (23.3–24.8 mummies a day). The intrinsic rate of increase (r_m) was 0.255 offspring per female per day. The parasitoids were then reared at eight constant temperatures between 15 and 32.5°C. The developmental time from egg to adult emergence decreased from 27.8 to 9.8 d. The lower developmental thresholds (T₀), estimated by linear regression, for the egg to mummy, mummy to adult, and egg to adult stages were 6.7, 6.8 and 6.7, respectively. The thermal constants for each of the three periods were 115, 126, and 243 DD. We compared these parameters with published data of A. asychis from other regions reared on different hosts and representative species of aphid parasitoids in Aphidiinae (Braconidae) reared on hosts including A. gossypii. The T₀'s of A. asychis were higher than those of Aphidius colemani and Aphidius matricariae when using A. gossypii.

The coffee berry borer, Hypothenemus hampei (Ferrari), is the major pest of coffee (Coffea spp.) worldwide. After adult eclosion, female borers leave the coffee fruit and disperse to colonize and oviposit in new host fruits. During this process, the flight muscles of females play a crucial role. The objectives of this work were to describe the morphology of the flight muscles of H. hampei females, to quantify changes occurring in the flight muscles during colonization in relation to age and oviposition, and to investigate hormonal control of flight muscle degeneration. Microscopic studies showed that H. hampei females have seven kinds of flight muscles: median dorsolongitudinal, oblique dorsolongitudinal, tergosternal, tergo-trochantinal, sterno-basalar, coxo-basalar, and coxo-subalar. Digital imaging of micrographs revealed that the surface area of flight muscles was significantly greater in flying females than in individuals that had oviposited in fruits. Both age and status of oviposition appear to affect the extent of flight muscle degeneration in this beetle species. Topical application of 2 µg of methoprene, a juvenile hormone analog, induced loss of muscle. This suggested that flight muscle degeneration is controlled hormonally in the coffee berry borer.

The green lacewing Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) is a common natural enemy of various insect pests in China and is frequently employed for augmentation biological control. Adults of this species perform migration flights after emergence, the nature of which affects its value for biological control program. In this manuscript, we report characteristics of C. sinica migratory populations captured during 2008–2009 using a light trap at Beihuang Island (Bohai Gulf), 40–60 km from mainland China, and their relationships with flight performance. In total, 1,452 migratory C. sinica adults were caught for these 2 yr. Throughout the sampling period, migratory populations consisted of >50% female individuals, most of which were in preoviposition period and had low degrees of ovarian development. During autumn, most migratory females were unmated. C. sinica females began oviposition since 7 d after emergence. Flight mill tests showed that 5-d-old females in preoviposition period flew over the longest distance (i.e., 4.50 ± 1.31 km) over 8 h and mating status did not affect flight performance. For 3-d-old individuals, males flew over larger distances than females, and unmated individuals exhibited stronger flight capability than mated ones. Hence, gender, mating status, and age all determine C. sinica flight performance. Based upon those findings, we can indicate that C. sinica migratory populations appear adapted to long-distance flights. This research should help understand C. sinica population dynamics and aid its incorporation within integrated pest management (IPM) packages for several crops.

Inconsistencies among results of previous studies on the induction of adult diapause in the western tarnished plant bug, Lygus hesperus Knight, could be either attributed to differences in the criteria being applied to assess diapause status or to differences in the sources of the bugs. To determine the cause of variation and to refine the criteria used to define diapause status, we obtained eggs from adults collected from the field and from long-term laboratory colonies. Concurrent experiments were conducted at two locations. L. hesperus were reared from egg to adulthood under photophases of either 10 or 14 h and at a constant temperature (26.6°C, Shafter, CA; 27.5°C, Maricopa, AZ). Adults were dissected at 10-d posteclosion to measure diapause status using both stringent and relaxed morphological criteria. Under both sets of criteria, offspring of field caught parents were more likely to enter diapause with short day exposure than those offspring from stock colonies. The relaxed criteria appeared appropriate for distinguishing diapause in males, whose reproductive organs can appear undeveloped after mating, although the stringent criteria appeared appropriate for females. Additional analyses were conducted to determine whether extended laboratory rearing influenced other behavioral or physiological traits. Bugs from stock colonies were more likely to mate, and to oviposit as virgins, than were bugs originating from the field. The results demonstrate a pronounced effect of colony rearing on L. hesperus physiology and behavior, and also have led to refinement of the criteria used to assess diapause status.

Temperature has a significant influence on the development rates of poikilotherms. There are many nonlinear mathematical models for describing temperature-dependent development rates. Among these models, the Sharpe-Schoolfield (SS) model with six parameters may be the most popular one. The reciprocal of the denominator in the SS model represents the probability of enzyme being in the active state. There is a reference temperature, 25°C, which was defined as a temperature at which the probability of enzyme being in the active state reaches its maximum. However, several examples of using the SS model to fit experimental data display that the probability of enzyme being in the active state does not reach its maximum at 25°C. For different taxonomic groups, the temperatures at which the probability of enzyme being in the active state reaches its maximum might be different. Thus, Ikemoto modified the SS model to a new model (i.e., the SSI model) which can meet the condition that at a particular temperature the probability of enzyme being in the active state can reach its maximum. In addition, Ikemoto related the SSI model to the linear model and devised an algorithm to estimate model parameters; however, that original program of Ikemoto is so timeconsuming that it limits the use of the SSI model. We provide a new program for a faster estimation of the parameters in the SSI model. One complete run of the new program takes less than 1 min (using R 2.10.1). This new program allows investigators to use the SSI model more readily. In addition, we test the linear approximation of the SSI model over three temperature ranges: low, middle, and high temperatures. We also provide a method for calculating the tangent at any point in the SSI model.

We used microsatellite markers to characterize the population structure of Coptotermes gestroi (Wasmann), an economically important termite species in the tropics. Eighty-five colonies were sampled from seven countries (Malaysia, Thailand, Singapore, Indonesia, the Philippines, Taiwan, and the United States [Hawaii]). Ten to 20 workers per colony were genotyped using eight variable microsatellite loci. STRUCTURE analysis partitioned the 13 spatially separated populations into four clusters. Individuals in the Peninsular Malaysia and Singapore population groups displayed admixture clusters. There was low genetic differentiation (F_ST = 0.073) among the Peninsular Malaysia populations, suggesting moderate gene flow among them. Comparatively, there was moderate genetic differentiation (F_ST = 0.192) and positive correlation between genetic distance and geographic distance among all of the 13 putative populations studied, which suggests limited gene flow among them. There was no significant isolation by distance within the three largest populations (Penang, Kuala Lumpur, and Singapore), presumably because humans aid the dispersal and fragmentation of colonies in these cities. However, significant isolation by distance was found in introduced populations (Taiwan). Population structure analysis demonstrated that C. gestroi populations in Taiwan were likely introduced from the Philippines.

The first report of resistance of the maize stem borer [Busseola fusca (Fuller)] to Bt maize (MON810) was made in the Christiana area of South Africa during 2007. The objective of this study was to evaluate the status of resistance of other populations of B. fusca to Bt maize. One greenhouse and two laboratory studies were conducted. B. fusca populations were collected on Bt maize as well as the adjacent refugia (conventional maize and non-Bt maize) in the Vaalharts area, 50 km from the Christiana site. Control populations were collected from sites where Bt maize was not planted. In the greenhouse study 720 potted plants were each artificially infested with 10 neonate larvae of the F1-generation after the field collected populations were reared through to adults. Numbers of live larvae and larval mass per plant were determined at regular intervals over a 35-d period. Larvae of the Christiana conventional population (Bt-susceptible) on Bt maize (CHR08ConBt) and Bethal conventional population (Bt-susceptible) on Bt maize (BET08Con-Bt) did not survive on Bt maize for longer than 12 d. The populations collected from both Bt (VAA08Bt-Bt) maize and refuges (VAA08Ref-Bt) at Vaalharts were resistant and the subsequent generation of larvae completed their life cycle on Bt maize. Similar results were observed in the laboratory experiments. This study confirmed resistance of B. fusca to the Cry1Ab toxin (MON810). The geographical distribution of resistance was shown to include at least the Vaalharts area, in addition to the original report for the Christiana area. These observations that larvae collected from refugia at Vaalharts was resistant, show that the efficacy of the refuge strategy is compromised in this area because the contribution of refugia did not produce large enough numbers of susceptible individuals to mate with moths of which larvae survived inside Bt maize fields.

Growers of Bacillus thuringiensis (Bt) crops often use refuges of non-Bt plants to delay pest resistance, but plant-to-plant gene flow between Bt and non-Bt crops could affect this strategy. Here we used simulation modeling to explore the consequences of pollen- and seed-mediated gene flow in cotton fields on the evolution of resistance in a generic pest. We modeled a landscape of 0.5-ha fields where growers used farm-saved seed, as could often occur in the developing world. Specifically, we examined the effects of moderate and high gene flow rates, larval feeding behavior, dominance of resistance, refuge type and abundance, and the interactions among these factors. With either completely dominant or completely recessive inheritance of resistance, gene flow among plants and larval feeding behavior had limited practical impact on resistance evolution. With intermediate dominance, however, moderate or high gene flow among plants substantially accelerated resistance evolution in some simulations where non-Bt cotton refuges were 5 or 20% of the cotton acreage. The acceleration was usually greater when larvae moved and fed indiscriminately among Bt and non-Bt cotton plants than when larvae were sedentary or discriminated among plant types. Adding alternative host plant refuges to the landscape delayed resistance, while increasing the non-Bt cotton refuge from 20 to 50% of the cotton acreage had positive, negative, or neutral effects, depending on dominance, the amount of alternative host plant refuges, and larval feeding behavior. The results suggest that, under certain conditions, reducing gene flow between refuges and Bt crops could help delay pest resistance.

To assess the potential dietary effects of insecticidal substances on the predacious ladybird beetle, Coleomegilla maculata De Geer, a Tier-1 laboratory testing system was developed. Artificial diets using shrimp eggs were developed, and a tier-1 bioassay examining C. maculata development and survival was designed based on those diets. To further measure the artificial diet in a Tier-1 testing system, larvae of C. maculata were fed the diet treated with different concentrations of an inorganic stomach poison, potassium arsenate (PA), or a cysteine protease inhibitor, E-64. The results demonstrated that the testing system was capable of detecting the dietary effects of both substances on the survival and development of C. maculata. With increasing concentrations of PA in the diet, fewer larvae developed to adults, with only 22.7% larvae surviving to the adult stage in the treatment with the highest content of PA (32 µg/g of diet). Likewise, dose-dependent responses also were found for other life-table parameters of C. maculata. Similar to the assays with PA, the survival rates of C. maculata consistently decreased with increasing E-64 content in the diet. Survival analysis showed that the insects fed E-64 at 50, 150, and 450 µg/g in the diet had significantly lower survival rates compared with those on the untreated artificial diet. The study presented here describes a robust testing system that will be useful for assessing the potential hazard (or toxicity) effects after dietary exposure of insecticidal compounds produced by GE plants or conventional insecticides on the ladybird predator, C. maculata.