The taxonomic status of Dendroctonus vitei Wood (Coleoptera: Curculionidae: Scolytinae) and Dendroctonus mexicanus Hopkins is supported by biological and morphological data. However, the differentiation of these species has been extremely difficult because most of the morphological characters have not been well illustrated and some of them are geographically variable. Seminal rod shape has been the only reliable characteristic to identify these species. The main purpose of this study was to look for new morphological characters for the identification of these species as well as to evaluate geographic variation of those previously reported characters in order to produce a comprehensive redescription of D. vitei. A total of 33 morphological characters from antenna, stridulatory apparatus, male and female genitalia, and external morphology were compared between the similar species D. vitei and D. mexicanus, and we identified five novel diagnostic characters and confirmed previously reported characters that differentiate these two species from each other and from other species in the Dendroctonus frontalis Zimmermann complex (sensu stricto). Furthermore, these characters and those of the seminal rod allowed us to re-evaluate some previously reported records for other species to broaden the known distribution of D. vitei.

Mites of the family Epidermoptidae (Acariformes) are permanent parasites dwelling on or in the skin of birds. Myialges Trouessart species are epidermoptids that have a hyperparasitic relationship with chewing lice (Phthiraptera) or louse flies (Diptera: Hippoboscidae). During 1993–2016 in Manitoba, Canada, 668 ducks (20 species), geese (five species), and swans (two species) were examined for lice. A total of 157 males, 191 females, and 539 nymphs of the menoponid louse Trinoton querquedulae (Linnaeus) (Phthiraptera: Menoponidae) were collected, of which 25 adult lice from three hosts (Mergus merganser Linnaeus, Lophodytes cucullatus (Linnaeus), Anas platyrhynchos Linnaeus; Aves: Anatidae) were infested with 38 female Myialges trinotoni (Cooreman). Overall prevalence and intensity of M. trinotoni was low, and mites showed no statistically significant preference between male and female lice. Myialges trinotoni is recorded from Canada (Manitoba) and United States of America (Alaska) for the first time, and two novel avian host species records (Lophodytes cucullatus and Anas platyrhynchos) are reported. The male of M. trinotoni (loose in bird washing) is illustrated and described. The barcode region of cytochrome oxidase subunit I (COI) was amplified from M. trinoton and compared with that of Myialges caulotoon Speiser, the only congeneric species for which COI is available, and interspecific divergence was high (25%).

Volumosinanew genus (Diptera: Sphaeroceridae: Limosininae) is described to accomodate the enigmatic Nearctic species Herniosina voluminosa Marshall, 1987 and its relationships are discussed. Based on morphological characters Volumosina is treated as part of the Limosina genus group along with Apteromyia Vimmer, 1929, Gigalimosina Roháček, 1983, Herniosina Roháček, 1983, and Limosina Macquart, 1835 but its position within the group remains unresolved. Volumosina voluminosa (Marshall, 1987) new combination is recorded from Canada and redescribed with new distributional and natural history data suggesting that it is an old-growth specialist associated with large woody debris. The gigantism of the male aedeagal complex of V. voluminosa is discussed.

This study assesses the effects of the veterinary medical product ivermectin (IVM) in a range of concentrations on adult reproductive physiology and larval mortality of the dung beetle Euoniticellus intermedius (Reiche) (Coleoptera: Scarabaeidae). The ecotoxicological tests comprised eight treatments, including two controls and six increasing ivermectina concentrations (3.16, 10.0, 31.6, 63.2, 100, and 316 µg IVM/kg fresh dung). After 10 days of exposure, the females were dissected and the brood balls counted (fecundity). The brood balls were opened 15 days later and live larvae were counted to estimate larval mortality. Ivermectin altered the morphology of the ovary and stopped vitellogenesis, causing oocyte resorption and thus decreasing fecundity. The 30% threshold of decline in fecundity was reached at 115.9 µg IVM/kg dung, with no observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) values of 10.0 and 31.6 µg IVM/kg dung, respectively. Larval sensitivity to ivermectin was higher, with a lethal concentration required to kill 50% of the population of 85.9 μg IVM/kg dung, and NOEC and LOEC of 3.16 and 10.0 µg IVM/kg dung, respectively. After cattle were treated with ivermectin at the recommended dose, the ivermectin concentration in their dung during the two first weeks after administration far exceeded the thresholds determined for E. intermedius.

Specimens of five species of woodpeckers (Piciformes: Picidae) from Manitoba, Canada, were weighed and examined for chewing lice, 1998–2015: downy woodpecker (Picoides pubescens (Linnaeus), n=49), hairy woodpecker (Picoides villosus (Linnaeus), n=23), pileated woodpecker (Dryocopus pileatus (Linnaeus), n=10), northern flicker (Colaptes auratus (Linnaeus), n=170), and yellow-bellied sapsucker (Sphyrapicus varius (Linnaeus), n=239). The relationship between body mass of each host species and infestation by seven species of lice was analysed: Menacanthus pici (Denny) from all host species, Brueelia straminea (Denny) from Picoides Lacépède species, Penenirmus jungens (Kellogg) from northern flicker, Penenirmus auritus (Scopoli) from the other four hosts, Picicola porisma Dalgleish from northern flicker, Picicola snodgrassi (Kellogg) from Picoides species, and Picicola marginatulus (Harrison) from pileated woodpeckers. Mean abundance of lice increased with the mean mass of their host. Neither the species richness of lice nor the prevalence of lice were related to host body mass. Host body mass explained 98% of the variation in mean intensity of louse infestation among hosts. The positive association of mean intensity and body size was also detected for three genera of lice. Louse intensity also increased with body size for individual birds, more so for some species of lice and hosts than others. Body size matters, but the adaptations that allow higher mean intensity on larger host species remain to be determined.

Severe mortality (93%) of overwintering larvae of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was recorded in March 2016 from green ash, Fraxinus pennsylvanica Marshall (Oleaceae), in Syracuse, New York, United States of America. In contrast, larvae collected from the same area in January exhibited <1% mortality. A strong cold front moved across New York from 13 to 15 February 2016 with temperatures plunging to nearly −40 °C in some areas. In many regions of New York where A. planipennis is established, temperatures dropped well below the reported supercooling point of overwintering larvae. To evaluate whether the extreme cold was linked to extensive mortality of larvae, trees were sampled from four areas that experienced a gradient of minimum temperatures on 14 February 2016. Overwintering mortality varied from ⩽5% to 93% among regions, with lowest survival in the coldest regions. When excised from their galleries, dead larvae were discoloured with brown spots or had black necrotic tissue in the spiracles or foregut. This is the first report of extensive cold-related mortality for this species in North America and highlights the stochastic nature of climatic extremes on invasive species populations.

Tetropium fuscum (Fabricius) (Coleoptera: Cerambycidae) is an invasive phloeophagous beetle established in Atlantic Canada that infests stressed and moribund Picea Dietrich (Pinaceae) species. Successfully colonised trees tend to be large in diameter (>10 cm diameter at breast height), but whether diameter influences host selection, larval performance, or both, is unknown. We tested the hypothesis that T. fuscum host selection is influenced by visual cues associated with tree diameter by counting the number of adults landing on 29 Picea rubens Sargent ranging in diameter at breast height from 12.2 to 37.5 cm. All trees were wrapped with sticky bands and baited with aggregation pheromone and host volatiles to make them equally attractive with regard to olfactory cues. We found significant positive relationships between the mean number of T. fuscum per sticky band and tree diameter, and also between phloem thickness and tree diameter. We conclude that the positive association between host diameter and T. fuscum infestation is at least partially due to the positive influence of diameter on landing rate, and that this may benefit the beetle because larger diameter trees have more food for developing larvae. However, there was no effect of tree diameter on the mean number of adults per m2 of sticky band and thus no evidence that T. fuscum actively selects larger diameter hosts based on visual cues. The positive relationship between landing rate and host diameter may simply be due to greater chances of airborne beetles being passively intercepted on larger versus smaller trees.

We tested the applicability of the “passive sampling” hypothesis and theory of island biogeography (TIB) for explaining the diversity of forest-dwelling carabid assemblages (Carabidae: Coleoptera) on 30 forested islands (0.2–980.7 ha) in Lac la Ronge and the adjacent mainland in Saskatchewan, Canada. Species richness per unit area increased with distance to mainland with diversity being highest on the most isolated islands. We detected neither a positive species-area relationship, nor significant differences in species richness among island size classes, or between islands and the mainland. Nonetheless, carabid assemblages distinctly differed on islands <1 ha in area and gradually approached the structure of mainland assemblages as island area increased. Small islands were characterised by abundant populations of small-bodied, winged species and few if any large-bodied, flightless species like Carabus taedatus Fabricius. Our findings suggest that neither the “passive sampling” hypothesis nor the theory of island biogeography adequately explain carabid beetle diversity patterns observed among islands in Lac la Ronge. Instead, we hypothesise that population processes such as higher extinction rates of large-bodied, flightless species and the associated release of smaller-bodied, flying species from intra-guild predation on small islands contribute to observed differences in the structure of carabid assemblages between islands.

Onthophagus nuchicornis (Linnaeus), Onthophagus taurus (Schreber), and Digitonthophagus gazella (Fabricius) (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini) are species of dung beetles that have been used in relocation programmes to accelerate the degradation of cattle dung on pastures. Exotic in North America, all three species have expanded their distributions since their introduction onto the continent. Here we report development of CLIMEX® bioclimatic models using data collected before 2011 that predict the eventual North American distributions of these species. Data collected after 2010 is used to validate these models. Model outputs identify large regions of the central United States of America suitable for establishment of O. nuchicornis and O. taurus where these species have not been reported. These results indicate that the latter two species may already be present in these regions and undetected, that they have yet to expand into these regions, and (or) that factors restricting migration or dispersal prevent these species from occupying these areas. Model outputs for D. gazella suggest that the species has largely reached its predicted maximum distribution. These models can be used to aid the success of future relocation programmes elsewhere in the world and (or) to predict regions where these species are likely to spread without human intervention.

Alfalfa weevil (Coleoptera:Curculionidae) is a major pest of alfalfa throughout the United States of America. Biological control research has disproportionately focussed on introduced parasitoids. Generalist predators may also be important, but experimental work evaluating their impacts is lacking. I combined a cross-site survey with a predator exclusion experiment to identify key predators, and test for impacts on weevil survival and plant defoliation levels in Montana and North Dakota, United States of America. Spiders (Araneae) dominated the complex, followed by Nabidae (Hemiptera) and Coccinellidae (Coleoptera). None of the dominant predators showed aggregative responses to weevil (Hypera postica (Gyllenhal); Coleoptera: Curculionidae) or pea aphid (Acyrthosiphon pisum (Harris); Hemiptera: Aphididae) densities across 10 sites surveyed. However, weevil densities were positively correlated with both coccinellid and nabid densities across transects at the experimental site. Thus, predator groups traditionally associated with aphids can show strong aggregative numerical responses to alfalfa weevil larvae at smaller scales. Predator exclusion revealed no significant predator effects on larval survival or alfalfa damage. However, final densities of pea aphids were significantly higher in exclusion treatments relative to controls. The results suggest that even under conditions where predators exert significant pressure on aphids, they may still have minimal impacts on weevils. Additional experimental work is necessary to determine the broader potential of generalist predators as alfalfa weevil control agents.

Quinoa, Chenopodium quinoa Willdenow (Amaranthaceae), cultivation has expanded beyond its historical range in South America into Europe and North America due to its high nutritional properties for human consumption. With the introduction of a crop into a novel range comes the potential for insect pest issues. Here, using traditional morphology and DNA barcoding we identify larvae of Scrobipalpa atriplicella (von Röslerstamm) (Lepidoptera: Gelechiidae), an introduced Eurasian moth, feeding on quinoa throughout the Prairie region of western Canada. Larvae can feed within the stem, on foliage, and directly on seed within the panicles, which can result in up to a 100% yield loss. We summarise distinguishing adult characteristics, potential host plants, and give initial remarks on the life cycle of this moth and its known host range in Canada. The potential for high yield losses makes further investigation of S. atriplicella a priority to maintain and expand sustainable quinoa production in Canada.

Cutworms (Lepidoptera: Noctuidae) constitute an important insect pest complex that causes damage to a variety of crops across western Canada and particularly in canola (Brassica napus Linnaeus; Brassicaceae) crops in recent years. However, individual cutworms are very difficult to identify to species based on morphology alone, particularly at the larval stage. Problems with pest identification can lead to difficulties in recommending appropriate management strategies for specific cutworm infestations. In the current study we have developed and applied a single-step multiplex polymerase chain reaction assay, based on the rRNA ITS2 genomic sequence, which can be used to identify, to the species level, individuals of the following five key cutworm species: Agrotis orthogonia Morrison, Euxoa auxiliaris (Grote), Euxoa ochrogaster (Guenée), Feltia jaculifera (Guenée), and Lacinipolia renigera (Stephens). This molecular identification tool will be a valuable asset in agronomic and ecological studies of cutworm infestations in the canola cropping system across western Canada and potentially could be used as a timely identification tool for determining pest infestations to the species level during outbreaks.