As reported recently by the authors, the third and fourth antennomeres of the antennal club of the bark beetle Dendroctonus vitei Wood (Coleoptera: Curculionidae: Scolytinae) possess conoid sensilla clustered inside spherical or bulb-shaped invaginations of the cuticle that resemble geological pit craters. These structures are novel relative to other Dendroctonus Erichson species examined. The morphology and ultrastructure of different sensilla types on the antennal club and within the pit craters of D. vitei are herein described in detail with the aid of light, environmental scanning electron, and transmission electron microscopy. Five types of sensilla were found: fluted, basiconica type I, and trichodea types I, II, and III. The pit craters were composed of clusters of multiporous sensilla basiconica arising from the inner surface of the concavities, and the morphology and ultrasructure of these sensilla are consistent with an olfactory function. The presence of pit craters in the D. vitei on the anterior side of the antennal club is an diagnostic character for this species and an autapomorphy of great taxonomic importance within the Dendroctonus frontalis Zimmermann species complex.

The annual abundance of chewing lice (Phthiraptera) was recorded from 1996 to 2015 in Manitoba, Canada, on two species of woodpeckers (Piciformes: Picidae). Yellow-bellied sapsuckers (Sphyrapicus varius (Linnaeus)) were infested with Menacanthus pici (Denny) (Amblycera: Menoponidae) and Penenirmus auritus (Scopoli) (Ischnocera: Philopteridae); northern flickers (Colaptes auratus (Linnaeus)) were also infested with M. pici, as well as two other Ischnocera, Penenirmus jungens (Kellogg) and Picicola porisma Dalgleish. The mean annual abundance varied from nine to 51 lice per bird for the four species, with prevalence, mean intensity, sex ratio, and nymphs per female also varying among louse species. Menacanthus pici populations on both hosts were unstable: abundance rose over two decades because of increasing prevalence, whereas the abundance of the other three louse species fluctuated around a mean. Population variability was similar for the lice on both hosts, with the metric, PV, ranging from 0.41 to 0.51 on a 0–1 scale, once the effect of the trend in abundance for M. pici had been removed. Although the population dynamics for species of lice on these two woodpeckers were distinct, inter-specific differences in population stability were less pronounced than observed in the few other species of bird lice studied in this way.

Two distinct experiments were carried out to assess the trans-generational and within-generational effects of the parasiticides ivermectin and moxidectin to dung beetles (Coleoptera: Scarabaeidae). In the first experiment, the fertility of Euoniticellus intermedius (Reiche) (Scarabaeinae) was assessed for individuals developing in dung containing 10 µg ivermectin/kg fresh dung, a residue concentration previously shown to be sublethal to larval development. Our results showed that the fertility of adults exposed to these residues as larvae was unaffected. In the second experiment, the fertility of Agrilinus constans (Duftschmid) (Aphodiinae) was determined after females were allowed to feed for three weeks on dung containing different concentrations of moxidectin residues (five concentrations ranging from 0.32–32.00 mg/kg dry dung). The fertility of females was not affected, regardless of the concentration to which they were exposed, even when they were exposed to high moxidectin residues that killed all the offspring. The combined findings of these two experiments emphasise that sublethal effects should be included in models that assess the nontarget effects of faecal residues to insects breeding in dung of livestock treated with veterinary medicinal products.

Crucifer flea beetle, Phyllotreta cruciferae (Goeze) and striped flea beetle, Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae) are the most chronic and economically important flea beetle pests of cruciferous (Brassicaceae) crops in western Canada. There have been reports that populations of P. striolata are increasing in numbers and expanding their geographic range. Climate is the fundamental factor regulating the distribution and abundance of most insect species. Bioclimate simulation models of the two flea beetle species were developed to assess climatic factors influencing shifts in their geographic distribution and density. The results fostered a better understanding of how the two species responded to selected climate variables. Growing seasons with above average precipitation were predicted to favour the geographic distribution of P. striolata more than P. cruciferae. Both P. cruciferae and P. striolata were sensitive to temperature changes in the range of −2 °C to +2 °C. The ecoclimatic index (suitability index) for P. cruciferae increased with increasing temperatures, whereas the index for P. striolata declined with increasing temperatures. This study highlights the regions of the Prairies and Boreal Plains Ecozones that are most sensitive to shifts of the two populations and which may require changes in insecticidal seed treatments for effective control.

Neothaumalea atlanticanew genus, new species (Diptera: Thaumaleidae), is described from the state of Santa Catarina in southern Brazil. This represents the first thaumaleid collected east of the Andes mountain range. The egg, larva, pupa, and both adults are described and illustrated, distribution map presented, and phylogenetic affinities discussed. A key to the genera of South America is also provided.

Long-term trap catches of seedcorn maggot, Delia platura (Meigen), onion maggot, Delia antiqua (Meigen), and cabbage maggot, Delia radicum (Linnaeus) (Diptera: Anthomyiidae), were used to test the hypothesis that related species have more similar population variability than unrelated ones. Annual abundance was estimated from trap catches for 32 years (two species) or 17 years (one species). Population variability was quantified as PV, a proportion between 0 and 1. The three Delia Robineau-Desvoidy species had PV values of 0.51–0.55 that did not differ significantly. These PV values were found to differ significantly from two unrelated species studied over the same time period in the same habitat, which had PV values of 0.39 and 0.67. The hypothesis that related species have more similar population variabilities than unrelated species in the same habitat was supported. These data strengthen the view that PV is a species-specific trait reflecting the adaptation of life histories to their habitat, with related species showing more similar adaptations than unrelated species. The polyphagous and saprophagous seedcorn maggot had PV similar to the two oligophagous herbivores, casting doubt on the hypothesis that more generalist feeders have less variable populations than more specialised feeders.

Adult size is the trait most closely correlated with reproductive output in insects, but may also have important selective implications determining additional fitness gains. In longhorn beetles, adult size-mediated ultimate benefits may arise from mate choice, male antennal spread width or male fighting for mates. In this paper, we examined factors potentially shaping adult size of Cerambyx welensii Küster (Coleoptera: Cerambycidae), an emergent oak (Quercus Linnaeus; Fagaceae) pest. Sex ratio and adult length/weight allometric relationships were also explored. Overwintering adults were collected inside oaks in Extremadura (southwestern Spain) during 2011–2017 to ensure that larval development was completed in the wild. Sex, host species, and wood quality affected adult size, though some interactions occurred and among-host differences were weak. Adults collected inside older trees and wider branches were significantly larger. Adult size was unaffected by either elevation, aspect, or population density. There was a robust allometric scaling in both sexes between elytral/adult length and weight, females being heavier than males and males longer than females when adults were large. Female-biased sex ratios occurred in old/veteran trees and in dense/crowded larval populations. We discuss these results from an evolutionary perspective considering the potential impact of C. welensii adult size on population dynamics and management tactics.

Investigations of light sensitivity and its physiological effects on insects developing within subcortical tree tissues are limited, presumably due to the assumption that cryptic microhabitats are completely devoid of light. In this study, we documented light-mediated behaviour and opsin gene expression in larvae of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), an extremely important forest insect that is well adapted for development beneath the bark of pine (Pinus Linnaeus; Pinaceae) trees and is eyeless in the larval stage. Larvae were negatively phototactic, as they selected dark over light microhabitats in phototaxis assays. We recovered long-wavelength opsin transcripts from all life stages, including eggs and larvae, suggesting that D. ponderosae is photosensitive throughout its entire life cycle. Our results imply that photosensitivity contributes to immature D. ponderosae survival and that extraocular photoreception could be common among bark beetle larvae.

Insects of the family Nabidae (Hemiptera) are generalist predators commonly found in agroecosystems, but little is known about their predation rates on common pests of forage crops. We determined the functional response and prey preference of Nabis Latreille species to two common leafhopper pests of red clover (Trifolium pratense Linnaeus; Fabaceae): Agallia constricta Van Duzee (Hemiptera: Cicadellidae) and Ceratagallia agricola (Hamilton) (Hemiptera: Cicadellidae). We also determined the survivorship of A. constricta to predation by Nabis species over the course of five days. The Nabis species displayed a Type III functional response to both leafhopper species with a preference for A. constricta. The 10-A. constricta/cage treatments and 20-A. constricta/cage treatments had the highest survival probabilities after five days with survival probabilities of 0.19 and 0.23, respectively. These results indicate that Nabis species may help in controlling leafhopper populations in forage-crop systems.

The depth at which pitfall traps were sunk into the ground and the resulting catches of epigaeic Carabidae (Coleoptera) and Staphylinidae (Coleoptera) assemblages in subhygric to hydric ecosites with very deep organic soil layers was investigated in the upper foothills ecoregion of Alberta, Canada. Traps were installed at seven sites, with six surface traps (the pitfall trap lip <5 cm below soil surface) and six deep traps (the pitfall trap lip >20 cm below soil surface) at each site. A total of 5289 beetles representing 75 taxa were collected. There were no significant effects of trap depth on catch. Rarefaction estimates of species diversity were higher in surface pitfall traps for both taxa. The similarity of pooled catches between deep and surface traps was on average 75%, suggesting that both trap types were collecting similar faunas. We found no advantage to using deep pitfall traps in addition to surface traps to sample the epigaeic fauna of wet forest stands and peatlands.

DNA barcode analysis of specimens belonging to the genus Histeromerus Wesmael, 1838 (Hymenoptera: Braconidae) reveals the presence of two species in North America. One is identified as H. canadensis Ashmead, 1891, which is widely recorded in North America, while the other is H. mystacinus Wesmael, 1838, a species formerly known only from the western Palaearctic.

More than a decade after its discovery in North America, the European woodwasp, Sirex noctilio Fabricius (Hymenoptera: Siricidae), has not been an aggressive tree killer in northeastern North American pine (Pinus Linnaeus; Pinaceae) forests. Concern that S. noctilio has potential to become a more aggressive pest as it spreads south, or as environmental conditions change, is warranted, because it has caused extensive pine losses on other continents that it has invaded. We observed S. noctilio impact and attack behaviour in eight pine stands throughout Ontario, Canada annually for a five-year period (2012–2016). Sirex noctilio impact was variable in unmanaged pine forests; it killed 3–48% of pine stems, and 3–36% of pine basal area. Most S. noctilio-caused mortality was limited to suppressed and intermediate trees. Of the 17% of pines in the entire study that were affected by S. noctilio, many (44%) were attacked in multiple years. Depending on the year, between 46% and 79% of trees remained alive in the year immediately after attack, which suggests that many study trees were at least initially resistant to attack by S. noctilio. Though its impact appears to be limited in most forests for now, we recommend that observations continue in future years.

The pine needle scale, Chionaspis pinifoliae (Fitch) (Hemiptera: Diaspididae), has the status of an emerging pest in Christmas tree (Pinaceae) plantations in Québec, Canada. The scale is not known to cause any significant damage yet and is not generally monitored by growers. However, it can be an obstacle for exportation to Christmas tree markets where scale insects are strictly regulated. In this study, we describe its life cycle in Christmas tree plantations in southern Québec. We confirm the presence of both parthenogenetic and sexual forms of the scale on Fraser fir Abies fraseri (Pursh) Poiret (Pinaceae) grown as Christmas trees, and of parasitoid and Coccinellidae (Coleoptera) specialists that could contribute to its control.

An assessment of the effects of competitive behaviour and sex on seven selected life history traits of Drosophila melanogaster Meigen (Diptera: Drosophilidae) was made under precisely regulated larval density. Contrary to the conditions of crowding, as considered in many previous studies, the low scale of density enabled assessment of the life history traits at the individual level with higher precision and low variations. The 0-day-old first instars were reared with the relative density of 1,2, 3, and 4 individuals with optimal food until the adults emerged. The life history traits like age at pupation, age at eclosion, adult body weight, adult body length, wing length, and adult survival were used as response variables. Both the density and sex of the competitors were considered as predictors of the life history traits and a stronger effect was evident in the female sex than in males, which is statistically significant. Result also revealed the effect of competitive behaviour was more intense in case of same sex competitors than of opposite sex. In all instances, the life history traits exhibited a trend of decreasing function with the increasing larval rearing density, in compliance with the norms of density-dependent effects on development of Drosophila Fallén and similar insects.

Two rearing records from trap nests set in São Paulo State, Brazil and one oviposition observation show that the parasitoid wasp Phlebopenes longicaudata (Westwood) (Hymenoptera: Eupelmidae: Eupelminae) parasitises the nests of oil-collecting bees of the genus Tetrapedia Klug (Hymenoptera: Apidae). Based on this and one previously published host record, species of Phlebopenes Perty are newly hypothesised to be parasitoids of solitary wasps and bees rather than wood-boring Coleoptera. Other Eupelmidae reported as parasitoids of aculeate wasps are summarised.

Over 1000 species of arthropods have been recorded from cadavers worldwide. While conducting a study on the diversity and abundance of insects associated with pig (Sus scrofa Linnaeus; Mammalia: Suidae) carrion in the highlands of Chiapas, Mexico, we noticed the presence of thrips (Thysanoptera) in the collecting containers of traps. The thrips collected comprised the following species: Aeolothrips species (Aeolothripidae), Frankliniella brunnea Priesner (Thripidae), Frankliniella fusca (Hinds), Frankliniella trinidadensis Hood, Neohydatothrips portoricensis (Morgan) (Thripidae), Thrips simplex (Morison) (Thripidae), Wegenerithrips admirabilis Johansen (Thripidae), and Stephanothrips bradleyi Hood (Phlaeothripidae). These species were taken in Schoenly traps, a device designed to catch sarcosaprophagous insects. The thrips species reported in the present study have not previously been recovered from decomposing cadavers, and their occurrence suggests an attraction to one or more components of the trap, rather than an incidental presence. Albeit thrips are not considered forensically important, more studies are needed to elucidate their role in carrion ecology.

A rearing study of egg and larval parasitoids of hemlock looper (Lambdina fiscellaria (Guenée); Lepidoptera: Geometridae) was undertaken during an outbreak of this pest in Labrador, Newfoundland and Labrador, Canada. Six parasitoid species were found: Telenomus coloradensis Crawford and T. droozi Muesebeck (Hymenoptera: Platygastridae), Winthemia occidentis Reinhard and Blondelia eufitchiae (Townsend) (Diptera: Tachinidae), as well as one species of Phobocampe Förster and Mesochorus vittator (Zetterstedt) (Hymenoptera: Ichneumonidae). None of them was a new Canadian record. To facilitate understanding of the regional parasitoid assemblage in Labrador, we compiled all published records in Canada and collated all specimen records from the Canadian National Collection of Insects, Arachnids, and Nematodes (Ottawa, Ontario, Canada). This comprehensive list will aid researchers interested in potential biological control candidates for hemlock looper.

To determine resistance of Brassicaceae field crops to Contarinia Róndani (Diptera: Cecidomyiidae) midge complex (Contarinia nasturtii Kieffer and Contarinia undescribed species), field trials of two different host assemblages were undertaken near Melfort, Saskatchewan, Canada in 2014 and repeated in 2015. In both years the first midge adults appeared in early July, when most plants were starting to flower, and a second generation occurred in mid-August, past the period of crop susceptibility. In a trial studying 18 lines of six brassicaceous species, the lowest probability of midge injury was found on Camelina sativa (Linnaeus) Crantz lines in both years. No differences were found in the probability of midge injury among any of the 13 Brassica Linnaeus species lines tested, including commercial glyphosate-resistant and glufosinate-resistant Brassica napus Linnaeus canola lines, Ethiopian mustard (Brassica carinata Braun), brown or oriental mustard (Brassica juncea (Linnaeus) Czernajew), or Polish canola (Brassica rapa Linnaeus) lines. Probability of midge injury on Sinapis alba Linnaeus yellow mustard lines reached levels between those on Camelina sativa lines and those on Brassica lines. A second trial examining 14 current commercial glyphosate-resistant Brassica napus canola cultivars found no differences in susceptibility to midge feeding among any cultivars tested. More plants were damaged in 2015 in both studies, and damage reached maximum levels earlier in 2015 than in 2014.

Flea beetle (Coleoptera: Chrysomelidae) species and numbers were determined from yellow sticky traps (n=11 180) set out in canola (Brassica Linnaeus, Brassicaceae) fields at 300 site years and 15 ecoregions across the Canadian Prairie provinces in each spring of 2007–2011 and in North Dakota, United States of America in 2010–2011. Peak numbers and relative species abundance varied with year, site, and ecoregion. Phyllotreta striolata (Fabricius) was most common in northern ecoregions, whereas Phyllotreta cruciferae (Goeze) dominated nearer the 49th parallel. The proportion of P. striolata in northern areas increased dramatically compared with surveys in the 1970s. Phyllotreta striolata displaced Psylliodes punctulata Melsheimer as the most common flea beetle in the Peace River Lowlands, displaced P. cruciferae as the most common flea beetle in the Aspen Parkland of central Alberta, Canada, and increased in proportion in central Saskatchewan and much of Manitoba, Canada. Once rare in southern ecoregions, P. striolata was found there in increasing numbers. Temperature was the most consistent weather parameter to predict occurrence of both P. cruciferae and P. striolata. Although P. striolata became more numerous over years in four of seven principal ecoregions, P. cruciferae remained the predominant species on traps with the highest numbers of flea beetles.