We evaluated the host suitability and related traits of Trichoplusia ni Hübner (Lepidoptera: Noctuidae) and Chrysodeixis chalcites Esper (Lepidoptera: Noctuidae), which is nonnative in North America, for the native parasitoids Campoletis sonorensis Cameron (Hymenoptera: Ichneumonidae) and Copidosoma floridanum Ashmead (Hymenoptera: Encyrtidae), and the nonnative parasitoid Cotesia vanessae Reinhard (Hymenoptera: Braconidae). For the larval parasitoid C. sonorensis and C. vanessae trials, three-day-old larvae of both hosts were used, whereas one-day-old eggs of both hosts were used for the egg–larval parasitoid C. floridanum trial. For suitability parameters on each host exposed separately to each of the three parasitoid species, we measured parasitoid emergence (parasitoid success), parasitoids that did not emerge (parasitoid cocoon mortality), the proportion of male offspring (parasitoid sex ratio), hosts that developed into moths (host success), hosts that died without developing into moths or producing a parasitoid (host mortality), parasitoids emerging from cocoon masses (brood size), and the developmental times of parasitoids and hosts. For C. sonorensis, the native host and the nonnative host were found to be similarly suitable. For C. vanessae, the native host was more suitable than the nonnative host. For C. floridanum, the native host was suitable, whereas the nonnative host was not; however, sublethal effects on both the native and nonnative hosts were observed. The differential suitability of the hosts observed in this study contributes to the understanding of this measure as a dynamic factor in the expansion of parasitoids into novel host species.

The Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (Coleoptera: Curculionidae) antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH), has been used since 2000 to protect high-value trees and stands throughout western North America. Operational treatments involve placing individual releasers on a 12 m × 12 m grid throughout the area to be protected. In this study, six widely spaced trap lines were established with aggregation attractant–baited traps located 1, 3, 9, 27, and 81 m from a location where an operational MCH release device was alternately either present or absent, and changes in catches caused by the MCH device were assessed at all distances. Trap catches were suppressed by about 70% at one and three metres, by 50% at nine metres, by 30% at 27 m, and not at all at 81 m. Inhibition by the MCH device varied with distance (m) from the source according to the function 0.79 − 0.092x0.51 (R2 = 0.986). Decline of attractant inhibition with distance from the MCH device was much less steep than would have been expected if catch inhibition had varied directly with the average airborne concentration of MCH.

Reproductive phenology of organisms is modulated by biotic and abiotic factors, with direct effects on the demography. This study describes the annual reproductive phenology of Dichotomius satanas (Harold, 1867) (Coleoptera: Scarabaeidae, Scarabaeinae) of the cloud forest in eastern Mexico, through the morphological changes in the reproductive systems of individuals and their relationship with climatic conditions. Three stages of sexual maturity were recognised as occurring throughout the year: immature, maturing, and mature – with a higher occurrence of immature individuals. Abundance of immature and maturing females was explained by minimum temperature, but none of the environmental variables considered was related to mature females. Abundance of immature and maturing males was related to precipitation, while abundance of mature males was related to minimum temperature and precipitation. The phenology of D. satanas was markedly seasonal with a single peak of abundance corresponding to the reproductive period during the warm and rainy season, thus indicating a univoltine pattern of reproduction. Immature females were recorded before immature males, and no synchrony was observed between the maturing and mature males and females. We provide information pertaining to the reproductive biology of coprophagous beetles and highlight the importance of reproductive phenology as a tool with which to understand future environmental scenarios.

Laboratory experiments and field observations from August 2019 to April 2020 demonstrated that skipper flies (Diptera: Piophilidae) overwinter as larvae and likely present an obligatory winter diapause in Québec, Canada. Diapause was confirmed by the very few emergences of adults in the laboratory following collection from carrion at the end of summer and in fall, the migration of larvae deep in the soil, and the persistence of larvae inside carrion during the winter until the following spring when they became active again and initiated pupation (i.e., intra-puparial period). To our knowledge, our observations represent the first report of the overwintering of skipper fly larvae inside an animal carcass in North America. In addition, this winter diapause should be considered in forensic entomology when using the presence of skipper fly larvae on a body to estimate the time elapsed since death.

Syrphids (Diptera: Syrphidae) are a diverse and widespread family of pollinating flies. Their diverse life history traits not only allow them to thrive in a wide range of habitats but also make them potential bioindicators of environmental change. Here, we report on their distributions from a previously understudied and undeveloped part of northern Ontario that is a large part of the third-largest wetland in the world. Samples were collected from across the region between 2009 and 2016, using numerous sampling methods. Of the 122 species identified from 1514 specimens, six are new provincial records to Ontario. Five species were collected over 800 km from their previously known ranges, some of which were west of the Rocky Mountains. Of all the trapping methods employed in the study, Malaise traps were found to be the most effective at catching syrphid species. This work updates known range and provincial records for more than 100 species of syrphids, bringing into clearer focus their distribution throughout this region.

Insects are usually considered to be excluded from the marine environment. A small number of species, however, are considered to be marine, due to spending some portion of their life cycle in salt water. We use natural history collection specimens, in-field observations, and molecular analysis to generate new locale records and natural history data for seven insect species. All seven species are associated with barnacles (Balanomorpha: Balanidae, Chthamalidae) along the Pacific coast of Canada, the United States of America, or Japan. Use of DNA barcode analysis confirms the monophyly of three species of Oedoparena (Diptera: Dryomyzidae). Natural history collection specimens expand the geographical range and illuminate the phenology of Oedoparena spp. In-field observations record direct associations between three species of Thalassosmittia (Diptera: Chironomidae), Diaulota densissima (Casey) (Coleoptera: Staphylinidae), and intertidal barnacles from various locations in British Columbia, Canada. Barnacle host associations and microhabitat preferences are proposed for all species. A new definition of what constitutes a marine insect is offered.

Essential oils produced by plants are a rich source of metabolites that can have toxic or behaviour-modifying effects on arthropods. Some essential oils have shown promise in management of the mite Varroa destructor Anderson and Trueman (Mesostigmata: Varroidae), a parasite of western honey bees, Apis mellifera Linnaeus (Hymenoptera: Apidae). Essential oil and its components from common yarrow, Achillea millefolium Linnaeus (Asteraceae), are reported to have both insecticidal and repellent properties for other arthropod pests and may have activity against V. destructor. Here, we evaluate responses of V. destructor towards common yarrow essential oil using gas chromatography paired with electrotarsal detection. We identified 38 essential oil components that elicited electrophysiological responses from V. destructor. Components of common yarrow essential oil identified as electrophysiologically active in this study are reported elsewhere as active components of other management strategies for V. destructor infestations (e.g., thyme oil; Thymus sp. (Lamiaceae)). Pending behavioural assessment, the efficacy of common yarrow essential oil in honey bee colonies infested by V. destructor should be explored in field conditions.

Wheat midge, Sitodiplosis mosellana Géhin (Diptera: Cecidomyiidae), is an invasive pest of wheat, Triticum spp. (Poaceae), in North America and is found in all wheat-growing regions of the world. Wheat midge biology, particularly post-diapause emergence of adults, varies with geographic region. The biology of wheat midge has not previously been examined in the northernmost area of its range in Canada – the Peace River region of Alberta. Wheat midge adult emergence was compared in situ to two phenological models of wheat midge emergence developed in other geographic regions. In-field adult emergence did not match the published phenological models. In the Peace River region, adults emerged later than are predicted by both models and precision for both models was low. With the Saskatchewan model, accumulated rainfall that was more than 110 mm in May and early June delayed emergence, whereas accumulated rainfall that was less than 43 mm during that period caused earlier than predicted emergence. Multiple peaks of wheat midge emergence, up to 20 days apart, were observed at some sites, supporting the Jacquemin model depicting “waves” of emergence. Including differences in soil temperature accumulation related to precipitation and optimising the model temperature thresholds would improve accuracy of the current Canadian phenological model in the Peace River region.

The first western Canadian records of the European carabid, Nebria brevicollis (Fabricius) (Coleoptera: Carabidae), are reported from Vancouver, Coquitlam, and Delta, British Columbia, Canada. A species description is provided to facilitate identification of this new invasive species. In addition, pitfall trap data are presented that demonstrate establishment of populations at four locations in Coquitlam. Trap catches were substantially higher at one anthropogenic meadow site than at three urban forest sites. Potential for further expansion of the range of N. brevicollis in British Columbia and beyond is discussed.

Binburrum Pollock, 1995 is a small group of fire-coloured beetles (Tenebrionoidea: Pyrochroidae: Pilipalpinae) endemic to Australia with five described species. Herein, three new species of Binburrum – B. articuno (southeastern South Australia), B. moltres (northeastern Queensland, Australia), and B. zapdos (northeastern Queensland) – are described based on comparative anatomy, highlighting the underestimated diversity of this genus. Binburrum angusticollis Pollock, 1995 is newly recorded from New South Wales, Australia. Descriptions of new species are supplemented with digital photographs and scientific illustrations of habitus and salient structures. A key for the identification of Binburrum is provided.