Variation in the seasonal occurrence of asexual and sexual phenotypes of Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) is quantified for a local population in southern Manitoba, Canada. To survive winter, summer asexual generations must produce a sexual generation in a timely way at the end of the season, so that females can lay overwintering eggs. This transition is controlled by day length, which varies in a fixed seasonal pattern with latitude, and the local pattern of day length selects for an appropriate photoperiodic response. Substantial variation in the timing of production of males and mating females occurs among locally collected genotypes. Some of the variation is due to the arrival of long-distance dispersers (1000 km or more), and some is consistent with shorter but still long-distance dispersal. Some of the variation is due to year-to-year changes in late summer temperature. The critical day length in nature, which corresponds to critical photoperiod, increases as the average temperature decreases. This temperature modulation is adaptive because it allows many genotypes to produce some sexual phenotypes before the end of the season, although their photoperiodic responses are characteristic of long-distance dispersers and inappropriate to local day lengths.

The ash leaf-cone roller, Caloptilia fraxinella (Ely) (Lepidoptera: Gracillariidae) is an introduced leaf-mining moth of horticultural ash trees (Fraxinus Linnaeus; Oleaceae) in Western Canadian Prairie cities. Here, we identify the dominant parasitoid of this leaf-mining moth as Apanteles polychrosidis Vierek (Hymenoptera: Braconidae) and document its emergence pattern, courtship, mating, and host acceptance behaviours. Apanteles polychrosidis adult emergence is protandrous and mating occurs soon after female emergence. Male A. polychrosidis can mate multiple times in short sequence with a mean copulation time of 49 seconds. It is likely that A. polychrosidis overwinters in an alternate larval host, after emergence from C. fraxinella. Mated female A. polychrosidis readily parasitise an alternate host, the obliquebanded leafroller (Choristoneura rosaceana (Harris); Lepidoptera: Tortricidae), known to overwinter as larvae. Through rearing C. fraxinella pupae, we describe the remainder of the parasitoid complex of C. fraxinella, in order of parasitism rate, as Diadegma Förster (near Diadegmafenestrale (Holmgren)) (Hymenoptera: Ichneumonidae), three Sympiesis Förster species (Hymenoptera: Eulophidae) (Sympiesissericeicornis (Nees von Esenbeck), one near Sympiesisviridula (Thomson) and one unknown species), and Pteromalus phycidis (Ashmead) (Hymenoptera: Pteromalidae) and show that several Sympiesis species can be hyperparasitic on A. polychrosidis. Caloptilia fraxinella density within the tree canopy is highest in the lower canopy. Host density and abiotic factors such as temperature and light intensity do not influence the within-canopy distribution of most parasitoids except Sympiesis species, which preferred the northern canopy.

We have recently shown that firebrats, Thermobia domestica (Packard) (Thysanura: Lepismatidae), carry, and deposit with their faeces, the symbiotic bacterium Enterobacter cloacae (Jordan 1890) Hormaeche and Edwards 1960 (Enterobacteriaceae) and the symbiotic fungus Mycotypha microspora Fenner, 1932 (Mycotyphaceae), and that these microbes induce arrestment behaviour and aggregation of firebrats. Here, we tested whether giant silverfish, Ctenolepisma longicaudata Escherich (Thysanura: Lepismatidae), and common silverfish, Lepisma saccharina (Linnaeus) (Thysanura: Lepismatidae), also arrest in response to these two microbes. In dual-choice bioassays, E. cloacae arrested firebrats but not giant silverfish or common silverfish, whereas M. microspora arrested firebrats and giant silverfish but not common silverfish. As close relatives, firebrats and giant silverfish have similar microclimate and nutrient requirements and may use M. microspora as the same aggregation cue when they aggregate in hot and humid microclimates where M. microspora proliferates and breaks down cellulose. As a more distant relative to firebrats and giant silverfish, common silverfish seem to require a different as yet unknown aggregation cue or signal, possibly one that is indicative of the type of microclimate (room temperature; high humidity) they prefer.

Stormwater catch basins form part of artificial drainage systems in urban areas and can provide larval habitat for mosquito vector species of West Nile virus (WNv), such as Culex pipiens Linnaeus (Diptera: Culicidae). We evaluated the impact of management techniques and targeted applications of larvicide on larval populations of this potential WNv mosquito vector species in catch basins from the Lower Mainland of Vancouver and on Vancouver Island of British Columbia, Canada. A mixed effects logistic regression model described the relationship between larval presence and larvicide treatment while controlling for other parameters. Parameter estimates showed that larvicide treatment reduced the odds of larvae presence by a factor of ∼7.23. The model also revealed relationships between larval presence and water temperature and adjacent land use but larvicide treatment consistently reduced the presence of larvae regardless of these other factors. This knowledge can now be used to prioritise and target control efforts to most efficiently reduce WNv mosquito vector populations, and most effectively reduce the risk of WNv transmission to humans. A similar research strategy could be applied to emerging threats from other potential mosquito vectors of disease around the world, to help lower the incidence of mosquito-borne disease.

Spiders (Araneae) were sampled in white spruce (Picea glauca (Moench) Voss (Pinaceae)) dominated stands from the ground and shrub layers, and from several overstorey strata to assess patterns in species composition and diversity (alpha and beta) along the vertical gradient (0–12 m above ground). Overall, 3070 adult spiders in 15 families and 76 species were collected, with the ground layer accounting for the highest species richness (40 species) followed by the mid-overstorey (36 spp.) and the shrub layers (33 species). Vertical stratification was apparent in the samples: richness clearly decreased with height, and species turnover between the ground, shrub, and mid-overstorey levels was evident, suggesting that species composition in each layer was highly distinctive. Within the mid-overstorey stratification was less obvious but both species richness and spider abundance were predicted significantly by height from the ground and branch size. Given the role of late-seral conifer stands for maintaining old-growth species, understanding diversity patterns across strata provides basic knowledge to support forest management decisions that effectively conserve spider species and assemblages. It is clearly important to include higher canopy layers in considering impacts of forestry on biodiversity in the boreal mixedwood.

Pupae of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), from Kennewick and Roslyn in Washington State, United States of America, were subjected to different soil and air moisture conditions to test the hypotheses that adult emergence from dry and moist soil is similar and is greater and occurs earlier at high than low relative humidities (RHs). Adult fly emergence from 0–57% saturated loam soil did not differ in Kennewick (64.8–75.1%) and Roslyn (81.7–86.6%) populations. Emergence did not occur from 76% saturated loam soil. In a RH experiment using dry soil, emergence of Kennewick flies was highest at 97% RH (76.8%), intermediate at 12–74% RH (66.4–69.6%), and lowest at 3% RH (58.0%). Emergence of Roslyn flies was higher at 97% RH (85.6%) than 3% (69.2%) and 12% RH (74.3%), but it did not differ from that at 33% (76.9%) and 74% RH (79.4%). Flies emerged ∼2–3 days earlier at 97% RH than at 3–12% RH. An unnaturally low RH of 3% caused more flies to be deformed than higher RHs. High emergence of R. indifferens in dry and moist conditions likely contributes to its presence in a wide range of native and nonnative habitats.

A comparison is made between a three-year structured-sampling study that compared spider faunas of two tundra habitats and a single-year unstructured-sampling study, both within the Arctic Long-Term Experimental Research (LTER) field station at Toolik Lake, Alaska, United States of America. The three-year study documented 51 species and predicted a total of 60 species for the area. Our one season study documented 39 species, of which 24, or 62%, are not shared by the three-year study, raising the total count for the LTER to 75 species. These findings emphasise limitations of species richness estimation methods and help dispel the perception that Arctic tundras are homogeneous and species poor.

Laboratory experiments using field-collected females were carried out to determine the oviposition preference of the balsam fir sawfly, Neodiprion abietis (Harris) (Hymenoptera: Diprionidae) in New Brunswick, Canada. Unmated adult females given no choice among host–plant foliage laid ∼98% of available eggs on balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae), but only 8% and 10%, respectively, on white spruce (Picea glauca (Moench) Voss; Pinaceae) and black spruce (Picea mariana (Miller) Britton, Sterns, and Poggenburg). Given a choice among shoots from all three hosts in the same chamber, unmated females laid all but one egg in balsam fir. Host plant had no effect on female longevity, although there were nearly four- to eightfold more empty egg slits on balsam fir needles, owing presumably to the greater activity of females on this preferred host foliage.

Comparisons of past and current butterfly species distributions are being used to gauge the effects of climatic change in various parts of the world. Historic butterfly records from Herschel Island, Yukon, Canada, presented an opportunity to do such a comparison in an Arctic tundra region known to have a diverse butterfly fauna. We compared historic species records (1916–1983) with newly collected ones (2007–2009) to assess possible changes in species distributions. Of the 21 species documented for Herschel Island, six were newly found and two were not reconfirmed. We postulate that warmer temperatures facilitated the apparent northerly range expansions of several species by making butterfly flight and dispersal possible. This is supported by interannual comparisons on a smaller time scale, 2007–2009. During this period, we observed accelerated butterfly phenology and higher relative abundance of butterflies associated with earlier snowmelt and with earlier and more intense early summer heating.

The present study relates the survival rate of bagworm eggs to extreme winter temperature and weight of egg clutches. The eggs were collected in the spring of 2009 at 104 locations in the mid-western United States of America across a latitudinal range from 36.5–41.5 °N. Egg survival after a 1-week incubation period was overdispersed, suggesting that survival of individual eggs within a clutch is highly correlated. Logistic regression analysis revealed that the survival of eggs, assessed after 1 or 12 weeks of incubation, significantly increases with the weight of egg clutches and increasing minimum winter temperature (expressed as the maximum temperature during the coldest day of winter). Lethal temperature for 50% of egg clusters was −14 °C for clusters weighing 0.1 g and −18.1 °C for 0.4 g clusters. The regression model developed here provides a tool to forecast the persistence of bagworm populations in recently colonised locations in Michigan, United States of America and southern Ontario, Canada.

Within the family Cerambycidae (Coleoptera), (E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol) and (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (fuscumol acetate) have been shown to attract several species in the subfamily Lamiinae. However, it is not yet clear whether beetles within the subfamily actually produce these compounds as pheromones or rather respond to them as kairomones. We report here that male Astyleiopus variegatus (Haldeman) produce both fuscumol and fuscumol acetate, suggesting that the compounds are indeed pheromones for this species. We also determined that the absolute configurations of these compounds are (S)-fuscumol and (S)-fuscumol acetate by synthesis of both enantiomers of each.

Even though Arabica coffee (Coffea arabica Linnaeus, Rubiaceae) can self-pollinate, bees are important pollinators, without which there is lower fruit quality and yield. We studied bee diversity in coffee agroecosystems in Costa Rica during two coffee flowering seasons (2005 and 2006). Malaise traps were used as a passive sampling method to collect bees during coffee blooms. We collected 1012 bee individuals from three different site types: nonagricultural fields and shaded and unshaded coffee farms. Unshaded coffee farms had significantly higher species richness (S) and number of bee individuals (n) than did the shaded coffee farms and nonagricultural sites. Overall bee diversity did not differ among site types but evenness (J′) was significantly lower in unshaded coffee farms. Using a more detailed community analysis, there was a significant association between functional groups and habitat type with more species and individuals of small-bodied ground-nesting bees (Lasioglossum (Dialictus) Robertson) associated with unshaded coffee farms. A large proportion (49%) of bees collected were of this subgenus, which was never before reported as common in coffee agroecosystems. Further studies should establish whether Dialictus is important in coffee pollination. We propose strategies involving conservation of native bees through simple habitat management for small-scale coffee farms that may improve crop quality and quantity.

It is unrealistic to achieve high-resolution biodiversity inventories required to support local conservation strategies over large areas; however, benchmark associations between arthropods and ecosystem classification can support landscape scale biomonitoring. We investigated habitat associations of ground-dwelling spiders (Araneae), staphylinid beetles (Coleoptera: Staphylinidae), and carabid beetles (Coleoptera: Carabidae) in three forest ecosystems in northwestern Alberta, Canada and also studied the effect of variation in depth of pitfall trap installation on catch. Composition and diversity of all three taxa were correlated with the ecosystem classification map, and 20 species were strong indicators of particular habitats. The black spruce (Picea mariana (Miller) Britton, Sterns, and Poggenburg; Pinaceae) bog supported fewer species and individuals of beetles but this trend was not observed for spiders because of natural history traits associated with their performance in this environment. Pitfall trapping biases were constant among habitats enabling proper comparison of ground-dwelling invertebrate assemblages. Three species of beetles (Agonum retractum LeConte (Coleoptera: Carabidae), Pterostichus brevicornis (Kirby) (Coleoptera: Carabidae), and Quedius velox Smetana (Coleoptera: Staphylinidae)) were disproportionally active beneath the soil surface, as catches were greater in pitfall traps with the lip situated 15–25 cm below the soil surface. Thus, even highly standardised trap placement will influence the concept of biodiversity achieved through pitfall trapping, because some target organisms are disproportionately active in subterranean zones.

An infestation of Histiostoma Kramer sp. mites (Acari: Histiostomatidae) occurred in rearing colonies of the univoltine strain of plum curculio (PC), Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), established in 2010 in southern Québec, Canada. Tests conducted in a two-choice still-air vertical olfactometer with mite-infested and noninfested PC revealed that the number of beetles responding by walking towards normally attractive synthetic and natural odours was significantly lower for those infested with mites. Those mite-infested curculios that did discriminate between test odours and odour-free air all responded positively to the test volatiles, similar to the behaviour of noninfested insects. This indicates that mites affect PC ability to physically move towards attractive volatiles but not odour preference.

A new genus and species are described within the extinct tribe Haidomyrmecini, and tentatively placed within the subfamily Sphecomyrminae (Hymenoptera: Formicidae). Haidoterminus cippusnew genus and species expands the distribution of the bizarre, exclusively Cretaceous, trap-jawed Haidomyrmecini beyond their previous records in mid-Cretaceous Burmese and French amber, and into Laurentia. The new material from the Grassy Lake, Alberta, Canada collecting locality also provides evidence that these highly specialised, likely arboreal, ants persisted for an additional 20 million years, reaching the Late Cretaceous. Morphological features of H. cippus, such as the presence of an elongate antennomere II (pedicel), further support the argument that Haidomyrmecini may not actually belong within the subfamily Sphecomyrminae, and may warrant recognition at the subfamily level or inclusion as a highly autapomorphic clade within another subfamily. Despite the introduction of new fossil material, and the clarity of preservation in Canadian amber, the mystery of how Haidomyrmecini fed remains unsolved.

Site fidelity and long-distance homing are known to occur in nesting female Hymenoptera. We report here on the site fidelity and homing ability in males of five species of scoliid wasps (Hymenoptera: Scoliidae), a group whose females do not make nests but are ectoparasitoids of scarabaeid beetles (Coleoptera: Scarabaeoidea). The males of these wasp species patrol female emergence areas searching for mates. Based on mark-recapture data, we found that between 40% and 100% of marked males left the release area and travelled 50–800 m from the point of capture returning to their original patrol area. We discuss the adaptive significance of site fidelity and homing behaviour in Scoliidae, and propose hypotheses about the evolution of the homing behaviour in Hymenoptera. The homing ability of these primitive Aculeata may represent a case of convergent evolution with other Hymenoptera in which males patrol emergence areas in search of females. Additionally, this homing ability may serve as a preadaptation for the evolution of nest-provisioning and nesting habits in Hymenoptera.

In the present study, effects of body size and prey quality on reproductive attributes and longevity of two aphidophagous Coccinellidae (Coleoptera), Coccinella septempunctata (Linnaeus) and Coccinella transversalis Fabricius, have been investigated in laboratory conditions. Higher fecundity, egg fertility, and longevity were obtained in larger females of C. septempunctata on pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), and in C. transversalis on bean aphid, Aphis craccivora Koch (Hemiptera: Aphididae). Males of C. septempunctata survived longer than those of C. transversalis on both prey. Number of clutches was lower and clutch size was higher in early and late reproductive phase; the reverse was observed in the middle of the reproductive phase. Larger females of C. septempunctata and C. transversalis laid higher number of clutches than the smaller ones. Thus, both body size and prey quality affect reproductive performance in Coccinellidae, though size variation did not change the prey preference.