Although the use of nonhost plants intercropped among host crops has been a standard agricultural practice for reducing insect herbivory for millennia, the use of nonhost signals to deter forest pests is much more recent, having been developed over the past several decades. Early exploratory studies with synthetic nonhost volatile semiochemicals led to targeted electrophysiological and trapping experiments on a variety of bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) across three continents. This work disclosed a suite of antennally and behaviourally active nonhost volatiles, which are detected in common across a range of coniferophagous bark beetles. It also established the fact that dispersing bark and ambrosia beetles detect nonhost signals while in flight and avoid nonhost trees without necessarily landing on them. Later work showed that groups of synthetic nonhost volatiles, sometimes combined with insect-derived antiaggregants, are effective in protecting individual trees and forest stands. Further work in this system may lead to the development of a variety of new and useful tactics for use in various integrated pest management strategies.

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.

We investigated ecological patterns of richness and abundance of Anastrepha fruit flies, based on a long-term series with a dataset from 1998 to 2010, subdivided into four subseries describing pest management through the systems approach (integration of different measures, at least two of which act independently, with cumulative effects), and its impact on abundance and diversity of fruit flies. Richness and abundance were influenced by time and distance but to different extents. Spatio-temporal analysis taking into account the implementation of the systems approach revealed clear effects of the pest management on fruit fly richness and abundance. However, abundance was affected by the systems approach three years before richness was. Abundance and richness also showed different relationships with time and distance between orchards and forest. The Gompertz model, used to describe the relationship between area and species richness, was the function that showed the best fit to the data. The richness-partitioning analysis, which decomposes beta diversity, indicated different distributions of richness values and predictions for additive partitioning that were directly associated with the implementation of the systems approach. The spectral analysis projected different trends for peaks, indicating that the systems approach is able to delay the time for new population peaks of fruit flies.

Pseudoscorpions are microarthropods that are distributed from the equator to beyond the Arctic circle. Wyochernes asiaticus (Arachnida: Pseudoscorpiones: Chernetidae) is the northernmost species of pseudoscorpion and is broadly distributed in Beringia, an Arctic and sub-Arctic region that remained unglaciated during the last glacial maximum. Wyochernes asiaticus is anoxia tolerant and has moderate cold tolerance, but nothing is known about the molecular basis of their survival in Canadian polar environments. We de novo assembled and characterised the transcriptome of W. asiaticus collected from the Yukon Territory in northwestern Canada. We assembled an approximately 62.6-million base-pair transcriptome with a mean contig length of 1277, which was 76% complete, according to a benchmark universal single copy orthologue (BUSCO) analysis. We identified 1100 transcripts encoding proteins associated with stress tolerance in these pseudoscorpions, including heat shock proteins, antioxidants, ubiquitination and proteosomal proteins, and sirtuins. We also identified transcripts encoding putative venom proteins. We highlight eight transcripts with high sequence similarity to sequences of venom proteins (ctenitoxins and agatoxins) described from other pseudoscorpions. Our study yields the first transcriptome of a Beringian arthropod, providing important sequence information that will allow future investigation of how W. asiaticus survives in Canadian polar environments.

Stephanitis pyrioides (Scott) (Hemiptera: Tingidae) is an important insect pest of azaleas, Rhododendron Linnaeus spp. (Ericaceae), in the United States of America. Because neonicotinoids, insecticides traditionally used against S. pyrioides, pose a risk to pollinators and natural enemies, nursery growers have reduced neonicotinoid use and are seeking alternative management options. Novaluron, an insect growth regulator, elicits a transovarial effect by reducing the viability of eggs after exposure to S. pyrioides adults. However, stability and persistence of transovarial effects on adults following exposure are not clear. The objectives of this study were to determine (1) the persistence of the transovarial effect of novaluron for up to three weeks after a single adult exposure and (2) the residual activity of aged novaluron residues eliciting a transovarial effect against S. pyrioides after a single application. Stephanitis pyrioides density was significantly lower in the novaluron-treated adults than in the nontreated controls for up to 21 days. The novaluron residues deposited on azalea foliage aged up to 32 days significantly reduced the number of S. pyrioides nymphs compared to that of the nontreated control. There was no significant difference in the number of nymphs among the 7-, 17-, and 32-day-old novaluron treatments relative to the nontreated control.

The mountain pine beetle (Dendroctonus ponderosae Hopkins) (Coleoptera: Curculionidae) is a significant destructive force in the pine forests of western Canada and has the capacity to spread east into a novel host tree species, jack pine (Pinaceae). New populations have been documented in central Alberta, Canada, but the source populations for these outbreaks have yet to be identified. In this study, we use genetic data to identify parent populations for recent outbreak sites near Slave Lake, Lac La Biche, and Hinton, Alberta. We found the northern population cluster that entered Alberta near Grande Prairie was the source of the most eastern established population near Lac La Biche, and the range expansion to this leading-edge population has been too rapid to establish evidence of population structure. However, some dispersal from a population in the Jasper and Hinton area has been detected as far north and east as Slave Lake, Alberta. We also identified two potential source populations for the current outbreak in Hinton: most beetles appear to be from Jasper National Park, Alberta, but some also originated from the northern population cluster. These findings demonstrate the dynamic dispersal capabilities of mountain pine beetle across the Alberta landscape and the potential hazard of increased dispersal to newly established leading-edge populations.

The role of insects as pollinators within plant communities is well established, yet our knowledge of insect biodiversity in many habitats is lacking. Given the growing concern that insect biodiversity is declining, it is increasingly important to document insect assemblages from a wide range of geographic locations and habitats. Pan trapping is a common means of sampling local insect diversity. Many studies have found different insects associated with different-coloured pan traps. Here, eight different-coloured pan traps were used to sample local insect diversity in habitats supporting Platanthera (bog and rein) orchids on Vancouver Island, British Columbia, Canada. A total of 16 sites supporting seven orchid species resulted in 435 insects from 53 families being caught over 64.9 hours of pan trapping. Both Shannon and Simpson diversity index values were low despite sampling in markedly different habitats. Yellow traps caught higher numbers of insects, but no statistical difference was found among colours overall. No activity indicating pollination was recorded from a total of 254 insect observations over 21.5 hours. Our results contribute important baseline data on the diversity and behaviour of insect communities in orchid habitats of Vancouver Island and on the use of pan traps to characterise insect communities.

The southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae), is among the most destructive bark beetle pests of pines (Pinaceae) of the southeast and mid-Atlantic United States of America, Mexico, and Central America. Numerous volatile compounds can stimulate or reduce attraction of the beetle, but efforts to incorporate these into effective, practical technologies for pest management have yielded mixed results. Attractants have been incorporated into lures used in monitoring traps that are employed operationally to forecast outbreaks and detect emerging populations. The attraction inhibitor, verbenone, shows efficacy for suppressing southern pine beetle infestations but has not yet been adopted operationally. No effective semiochemical tree protectant has been developed for the beetle. We discuss complexities in the chemical ecology of the beetle that likely have impeded research and development of semiochemical management tools, and we describe basic science gaps that may hinder further progress if not addressed. We also report some supporting, original experimental data indicating (1) that a verbenone device can inhibit the beetle’s response to sources of attractant in a radius of at least several metres, (2) similar olfactory responses by the beetle to both enantiomers of verbenone, and (3) that pheromone background can cause conflicting results in semiochemical field tests.

Wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a major pest of wheat (Poaceae) that was first reported in the Peace River region of northwestern Alberta, Canada in 2011. Although parasitism is an important factor of mortality in wheat midge elsewhere, little is known about the prevalence, species, or distribution of wheat midge parasitoids in the Peace River region. To address this knowledge gap, we conducted a survey of wheat midge parasitoids in commercial wheat fields across the region in 2016 and 2017. For a given field, parasitism of wheat midge larvae ranged from 36 to 71%. All but one parasitoid (n = 2167) were identified as Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae). The exception was a specimen in the genus Inostemma tentatively identified as I. walkeri Kieffer (Hymenoptera: Platygasteridae). These findings identify parasitism as an important factor that is suppressing populations of wheat midge in the Peace River region, provide the first report of Inostemma walkeri for North America, and provide the first report of this species as a parasitoid of S. mosellana.

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.

This paper reviews the literature on the identification of 3-methylcyclohex-2-en-1-one (MCH) as the antiaggregation pheromone of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (Coleoptera: Curculionidae) and the development of successful management applications using the pheromone. Previously unpublished data from two studies on novel uses of MCH are included. The successful development of antiaggregation pheromone-based treatments for the Douglas-fir beetle is discussed in relation to efforts to develop similar treatments for other bark beetle species, and opportunities for future research on MCH and the Douglas-fir beetle are suggested.

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.

We report the strawberry blossom weevil, Anthonomus rubi (Herbst, 1795) (Coleoptera: Curculionidae), a species native to Europe, Asia, and North Africa, as established in British Columbia, Canada. This is the first report of A. rubi in North America. We provide a diagnosis of the species and compare it with other species of the genus Anthonomus Germar in Canada. This species is a pest of plants in Rosaceae Jussieu, including economically important berries such as strawberries (Fragaria Linnaeus) and raspberries (Rubus idaeus Linnaeus), and of native berries of importance to Indigenous peoples in Canada. Female weevils oviposit eggs inside developing flower buds and sever flower stalks, facilitating larval development inside damaged buds and thus reducing fruit yields. Surveys to confirm the presence of A. rubi conducted in 2020 found the weevil to be well established in cultivated and wild hosts throughout the Greater Vancouver area and Fraser Valley, British Columbia. At least one species of parasitoid wasp in the genus Pteromalus Swederus (Hymenoptera: Pteromalidae) has been found in association with A. rubi in the province. Future investigations are required to understand the biology of A. rubi in its new range, assess its impact on berries, and develop management strategies.

The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), can remain inside dry and deformed reproductive structures of cotton, Gossypium hirsutum Linnaeus (Malvaceae), known as dry bolls, during the cotton fallow to infest the next cotton crop. In this study, the influence of cotton cultivars and sowing densities on the formation of dry bolls was evaluated. In addition, dry bolls were dissected and internal structures that were related to boll weevil development were estimated. Finally, the presence and survival of boll weevils inside dry bolls were evaluated. The results indicate that the number of dry bolls, empty pupal cells, and emergence holes was influenced by cultivar and not by sowing density. Almost one-quarter (22.53%) of adult boll weevils examined was found alive inside the dry bolls after 10 weeks, which is slightly longer than the duration of cotton fallow in Brazil’s main cotton-producing regions. Therefore, remaining inside the dry bolls is an important survival strategy for boll weevils during the cotton fallow period, and cotton cultivars with a greater propensity for the formation of dry bolls might favour survival of the pest during this period.

The multicoloured Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), has become a pest in North American vineyards during harvest due to its adverse effects on wine quality. This study evaluated alternative products that may be suitable for use in vineyards as repellents to the beetle. Products were screened as repellent for multicoloured Asian lady beetle in short-term laboratory trials. Thirteen products significantly reduced the number of beetles on grapes, Vitis vinifera (Vitaceae). Products that showed a 50% or greater repellency were evaluated for residual repellency 24, 48, and 72 hours after application. In these trials, pine oil was highly repellent at each testing period, whereas the repellency of most other products decreased over time. Eight repellent compounds were evaluated in field trials in commercial vineyards that had high multicoloured Asian lady beetle populations. The number of beetles on vines was counted 2–6 and 24–28 hours after application. In the field, the most effective repellents overall were Biobenton and Buran, which reduced the number of multicoloured Asian lady beetles by 39 and 34%, respectively. The discovery of new repellents of multicoloured Asian lady beetle provides an opportunity to improve management of the pest in vineyards and to reduce risk of wine taint without using broad-spectrum insecticides.

Neonicotinoid insecticides are used to reduce crop damage caused by insect pests, but sublethal levels could affect development and reproduction in nontarget insects, such as monarch butterflies (Danaus plexippus) (Lepidoptera: Nymphalidae). To investigate the impact of field-realistic concentrations of the neonicotinoid clothianidin on monarch butterflies, we grew swamp milkweed (Asclepias incarnata) (Apocynaceae) in either low (15 ng/g of soil) or high (25 ng/g of soil) levels of clothianidin, or in a control (0 ng/g), then raised monarchs on the milkweed. Morphological traits of monarch caterpillars were measured during development and, once they eclosed, were mated as adults to quantify egg size and mass and the number of eggs laid. Although the effects of the treatment had complex effects on caterpillar length, width and volume of late-instar caterpillars were negatively affected. Fifth-instar caterpillars from the high-dose insecticide treatment had lower mass than other groups. Adult monarch butterflies raised on treated milkweed were larger than controls, but clothianidin exposure did not affect the number of eggs laid or egg size. Although the magnitude of the effect depends on clothianidin concentration, our results suggest that exposure to clothianidin during early life can impact monarch caterpillar development but is unlikely to reduce female reproductive output.

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.

The foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), and the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are among the serious insect pests found in greenhouses. The efficacy of microbial control against these insects has been demonstrated and can be enhanced by the combination of different microbial agents. This study evaluated the efficacy of Bacillus pumilus Meyer and Gottheil PTB180 and Bacillus subtilis (Ehrenberg) Cohn PTB185, used alone and together, to control these two aphids both in the laboratory and in greenhouse on tomato, Solanum lycopersicum Linnaeus (Solanaceae), and cucumber, Cucumis sativus Linnaeus (Cucurbitaceae), plants. The results from the laboratory tests showed an increase in mortality induced by all biological treatments. In the greenhouse, all treatments induced mortality rates significantly higher than that of the control for A. solani. Similarly, all treatments performed better than the control against A. gossypii, significantly reducing its reproduction. Furthermore, we found no additive effects when mixing products nor negative interactions affecting survival for the bacteria investigated. These microorganisms therefore have potential for use in biological control.

The current interpretation of two common European species, Mordellistena minima Costa, 1854 and M. pseudorhenana Ermisch, 1977, is based on misidentification. The confusion regarding the identity of the species is fixed based on the revised type material. Here, the species are redescribed, and diagnostic characters are provided. Mordellistena pseudorhenana is revalidated. Mordellistena emeryi Schilsky, 1895 is recognised as a new synonym of M. minima. Mordellistena sajoi Ermisch, 1977 is recognised as a new synonym of M. pseudorhenana. Lectotype and paralectotypes of M. emeryi are designated. Mordellistena pseudorhenana is reported for the first time from Bosnia and Herzegovina, Slovenia, and Switzerland. Two morphotypes of M. pseudorhenana differing in size and shape of the parameres are recognised. Morphological differences are quantified and displayed using principal component analysis. In addition, DNA barcodes have been used for the first time in family Mordellidae to examine the divergences between the species and to interpret the morphological variability observed in M. pseudorhenana. Low genetic divergences did not provide the evidence for considering the morphotypes as separate species. The discrepancy between the morphological and molecular evidence raises questions about the efficiency of the CO1 gene for Mordellidae identification and the stability of morphological traits conventionally used for species separation.

Transporting firewood can spread plant pests such as the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), which was discovered in Lower Michigan, United States of America in 2002. In 2005, Michigan banned the transport of hardwood firewood northwards across the Mackinac Bridge, which connects Lower and Upper Michigan. In 2005–2011, 479 drivers of 11 commercial vehicles and 468 private vehicles were interviewed. Firewood was collected in every month of the year, with most firewood collected in June–September. Of the 468 private vehicles surveyed, 400 carried firewood originating from Michigan, 64 carried it from 19 other American states, and four carried it from three Canadian provinces. Most vehicles (93%) were bound for Upper Michigan, 4% were bound for eight other American states, and 3% were bound for four Canadian provinces. Drivers transported 1–275 pieces of firewood, with 33% of drivers having 1–10 pieces and 87% having up to 50 pieces. Surrendered firewood represented 19 tree genera – 18 hardwood genera and one conifer. Of 59 vehicles carrying ash (Fraxinus) firewood, 15 had firewood with A. planipennis signs. Firewood was transported mainly for camping (76%), for weight (15%), and to be used at cottages (5%).