Rabbitbrush, Chrysothamnus Nuttall spp. (Asteraceae), is acommon perennial native shrub across the inland western United States. Inthe Columbia Basin growing district of Washington State, rabbitbrush isoften found in close proximity to potatoes and other agronomic crops, butits value as a conservation reservoir and source of parasitoids of merit inagriculture is unknown. Here, we define the aphid parasitoids frequentingrabbitbrush, their aphid host preferences, seasonal occurrence, and linkageor association with other aphids of economic and noneconomic importance.Extensive field collections, lab-holdings, and rearings were used to exploreand characterise the fauna. One new species of aphidiine parasitoid isdescribed and illustrated: Praon cowiche Hollingbery andPike, new species and a key to the parasitoids of rabbitbrushaphids is provided.

Galls of Diplolepis variabilis (Bassett) (Hymenoptera:Cynipidae) on their host plant Rosa woodsii Lindley(Rosaceae) support a diverse community of parasitoid and inquiline waspsthat exploit the gall inducer and the gall itself. Here, we studiedquantitative variation in local structure of the gall community in theOkanagan Valley of southern British Columbia, Canada, from the United Statesborder north, to test the hypothesis that dispersal limitation wouldgenerate a distance decay in gall community similarity. We also exploredgall community richness in relation to latitude, as the northern range limitof the gall inducer occurs within our study area. We found that gallcommunities exhibited strikingly similar composition across the studyregion, with most of the major inquilines and parasitoids present across thegall's range. However, the increased richness of rare parasitoid taxa nearthe northern range limits of D. variabilis generated amarginally significant positive relationship between gall community richnessand latitude. Overall, our study suggests that dispersal constraints do notinfluence the composition of the Diplolepis Geoffroy gallcommunity at regional scales, and that gall communities offer useful modelsfor studying the association between community structure and rangelimits.

Agricultural practices affect the biotic and abiotic conditions thatdetermine food and shelter for carabid beetles (Coleoptera: Carabidae). Wehypothesised that carabid communities would respond differently to 18 yearsof contrasted cropping practices in cereal-based rotations. We measured theeffects of tillage (MP: moldboard plough; CP: chisel plough; NT: no-till)and previous crop sequence (cereal monoculture versuscereal–forage/cereal–oilseed rotation) on carabid beetle activity density,diversity, and community structure in corn (Zea maysLinnaeus, Poaceae) at La Pocatière, Québec, Canada. Carabid beetles weresampled monthly from May to September 2006, using pitfall traps. Although 19carabid species were observed, assemblages were dominated by Harpalus rufipes (De Geer), particularly in the secondhalf of the season. Multivariate analyses indicated a strong affinity ofcarabid species for the NT treatment throughout the season. Crop sequenceand tillage had no effect on diversity (Shannon's H′ ≤ 1.3)and evenness of carabid assemblage, but species richness and activitydensity were greater in NT than in tilled systems. Peak activity density ofdominant species occurred at different times during the season, generally inaccordance with preferred breeding season. Many species had greater activitydensity in NT than in tilled treatments. Because of their granivorousfeeding habit, carabid populations such as that of H. rufipes could be an important asset to NT, given the limitedweed management options available for this system.

We tested the hypothesis that the conophagous Douglas-fir cone gall midge, Contarinia oregonensis Foote (Diptera: Cecidomyiidae),responds to infrared (IR) radiation and other electromagnetic wavelengthsassociated with cones of Douglas-fir, Pseudotsuga menziesii(Mirbel) Franco (Pinaceae). Early-season (March–April) thermographic imagesshowed that cone orientation (upright, horizontal, pendant) and cone colour(green, purple, green/purple) did not affect apparent cone temperature(inferred from thermographic images). Tree components significantly differedin apparent temperature with foliage being coolest and branches warmest.There was no significant difference in the number of larvae in cones ofdifferent colours, and adult midges were equally attracted to traps paintedgreen or purple, suggesting that cone colour does not affect ovipositiondecisions by gravid females. Adult midges were more strongly attracted towarm traps with IR frequency emissions higher than the background than tocold traps with IR frequency emissions lower than the background. They werealso more strongly attracted to warm branch-shaped traps than to warmcan-shaped traps. Collectively, these data indicate that the shape and IRattributes of Douglas-fir branches may serve as foraging cues for C. oregonensis.

We tested whether the known bird-biting mosquito, Culex pipiens Linnaeus (Diptera: Culicidae), is attracted to humanhosts by placing humans at ground level (∼1.5 m) or in the forest canopy (∼5m) in a Niagara woodlot. Modified Centers for Disease Control (CDC)miniature light traps (no light, no CO2) were placed next to thehuman hosts to capture the attracted mosquitoes. The human-baited traps werecompared with control traps (standard CDC miniature light traps with CO2, but no light). As expected from previous research, therewere more C. pipiens captured at the higher elevation thanat ground level. Generally, they were attracted to control traps more thanto human-baited traps at 5 m, whereas at 1.5 m there was no differencebetween the two trap types. As a comparison, most Aedes vexans (Meigen) mosquitoes were captured at the 1.5 m elevationbut there were significantly more captured in the control traps than thehuman-baited traps during all periods. Because C. pipiensis attracted to humans throughout the entire season at the 1.5 m height(where they might encounter humans), it is likely that C. pipiens can serve as a bridge vector of West Nile virus(WNV).

A well-accepted function of courtship in sexually dimorphic andcannibalistic spiders is suppression of female predatory responses. Wequantitatively analysed courtship in the western black widow, Latrodectus hesperus Chamberlin and Ivie (Araneae:Theridiidae), to determine the behavioural elements of the males’ courtshipthat are correlated with mating success and/or the females’ responses. The58% of males that engaged in web reduction elicited fewer aggressiveresponses from females and induced female quiescence more quickly than didmales not exhibiting web reduction behaviour. Our data suggest that webreduction by male L. hesperus functions in sexualcommunication, a context not previously explored.

Nymphs of lotic mayflies live in environments that are expected to give riseto different degrees of population structuring. Here we investigate two taxaadapted to different lifestyles. Baetis macani Kimmins(Ephemeroptera: Baetidae) lives in flowing water; brooks that mayperiodically dry out in the summer or freeze to the bottom in winter. Baetis jaervii Savolainen is mostly found in sedge beltsalong the shores of lakes. Most insects living in flowing water show lowlevels of among-population genetic differentiation within and amongcatchments. Levels of differentiation in the lotic species are thereforeassumed to be lower than in lentic B. jaervii. Here we testthis hypothesis. Mitochondrial DNA and allele frequencies of nuclear geneswere used to detect population structure in specimens originating from anextensive area from northern Finland. The genetic differentiation amongpopulations of the lotic B. macani is more than twice thecorresponding value for the lentic B. jaervii (FST 0.33 versus 0.15, while the mean FST between species was 0.33 andsignificant). The result is congruent within the cytochrome c oxidasesubunit I gene (COI) partial gene frequencies. We argue that the significantgenetic population structure, which only was found in the lotic B. macani, is differentiated as a consequence to the unpredictableenvironment as contrasted to the stable environment in standing bodies ofwater.

Predatory insects and spiders were collected from apple orchards in twogeographic regions of Central Washington State, United States of America toassess seasonal phenology and diversity of the generalist predatorcommunity. Arthropods were collected from orchard canopy every 3–7 days overtwo growing seasons (March–October) at seven organically managed and twoinsecticide-free orchards. Over 35 000 specimens and 80 species of spiders(Araneae), ladybeetles (Coleoptera: Coccinellidae), lacewings (Neuroptera),and predatory true bugs (Hemiptera) were collected. Composition of insectand spider communities differed between the two geographic regions.Indicator species analysis identified several species that had a significantassociation with one of the two regions. Counts of the most common taxa wereexamined in detail on a calendar date basis to determine seasonal phenologyof adult and immature stages. We observed substantial differences among taxain number of generations, seasonal timing of first appearance in orchards,overwintering stages, and seasonal occurrence of the adult and immature lifestages in orchards. Understanding seasonal phenology of natural enemies inorchards is a core requirement in integrated pest management programs forapple pests, and results of this study provide this information for thegeneralist predator community of orchards in the Pacific Northwest.

Little is known about the acarofauna associated with wood-boring beetles inCanada, including long-horned beetles (Coleoptera: Cerambycidae). Herein, weassessed the prevalence, abundance, diversity, phenology, and attachmentlocation of mesostigmatic mites (Acari: Mesostigmata) associated with Monochamus scutellatus (Say), and tested whether theabundance and prevalence of mites differed between male and female beetles.A total of 176 beetles were collected in two sites in eastern Ontario in2008 and 2009 using Lindgren funnel traps baited with α-pinene and ethanollures, and 71% of hosts had mesostigmatic mites. A total of 2486 mites werecollected, representing eight species, four genera, and three families(Digamasellidae, Trematuridae, and Melicharidae). Average prevalence wasvariable across mite species, and the number of mites per infested beetlealso varied across species. Many of the mite species collected in this studyhave been reported from other cerambycid species, as well as from otherwood-boring beetles, such as bark beetles. There was no significant sex biasin the abundance or prevalence of mites between male and female M. scutellatus, which suggests that there is no selective advantagefor mites to disperse on females. This study represents the firstquantitative investigation of the mites associated with M. scutellatus in Canada.

Tetropium fuscum (Fabricius) (Coleoptera: Cerambycidae) isa Palaearctic wood borer that has been established in Atlantic Canada sinceat least 1990. Neither the number of instars nor methods for determining theinstar of field-collected larvae have been documented for this species.Head-capsule width was measured for 949 T. fuscum larvae inorder to determine the number of instars in this species, estimate the meanand variance of head-capsule widths associated with each instar, andidentify whether head-capsule width is sexually dimorphic. Head-capsulewidth data were analysed using maximum likelihood analysis of mixture modelsand the Brooks–Dyar rule. Our results provide strong support for theexistence of six larval instars, with sexually dimorphic head-capsule widthsin instars five and six. The probability of misclassifying larvae intoinstar-specific and sex-specific categories ranged from 0.6% to 12.8%, withthe highest probabilities occurring when assigning a sex to fifth-instar andsixth-instar larvae.

Assessing biodiversity is essential in conservation biology but theresources needed are often limited. Citizen science, by which volunteersgather data at low cost, represents a potential solution for the lack ofresources if it produces usable data for scientific means. Scientificinventories for butterflies are often performed with a Pollard transect, astandardised surveying technique that generates high-quality data. Generalmicrohabitat surveys (GMSs) are potentially more appealing to amateursparticipating in citizen science projects because they are less constrained.We compare estimates of butterfly species richness acquired by Pollardtransects to those obtained by GMSs. We demonstrate that GMSs allowsurveyors to detect more butterfly species and a more complete portrait oflocal butterfly assemblages for the same number of individuals captured.