Population density affects the behaviour and population dynamics of insects, but the nature of that effect may depend on the degree of sociality. We experimentally manipulated initial population density of a subsocial insect, the Madagascar hissing cockroach, Gromphadorhina portentosa Schaum, 1853 (Blattodea: Blaberidae), to determine its effect on vital rates and population dynamics. In accordance with the predicted Allee effect, we hypothesised that intermediate cockroach population density will increase per capita birth rates and cause a higher population growth rate relative to smaller and larger population densities. After tracking 12 experimental populations (three replicates of four initial population densities) for 15 months, we found evidence of Allee effects in this insect. Per capita birth rates showed a quadratic response, with rates highest at intermediate population densities, suggesting a component Allee effect. Contrary to expectations for a demographic Allee effect, population growth rates showed negative density dependence. The proportion of adult females in the population increased with population density, but the mechanism for this increase is not known. Our findings provide evidence for at least one form of Allee effect in G. portentosa and shows a possible connection between subsocial behaviour and population-level responses.

Knowing the biology and ecology of Drosophila suzukii (Diptera: Drosophilidae) is important to predict its potential for permanent establishment in cold climatic regions. We studied the reproductive potential of postdiapause male and female flies collected in lowbush blueberry fields in late season over two years. After being submitted to a six-month cold-winter regime, survivors were exposed to a simulated springtime warming regime to monitor reproductive potential and expected population growth. Overwintered fly survivors of both sexes that were aged up to nine months after field capture reproduced successfully in spring and early summer when mated to nondiapause flies experimentally made available for mating as potential migrant colonisers from lower latitudes. Relative to control nondiapause flies, the lifetime fertility of postdiapause flies was reduced by 84% in females and 70% in males, revealing large fitness costs of reproductive diapause under cold stress. Modelling potential reproduction of overwintered flies in warming conditions using models parametrised for age-dependent fertility rate and diapause status showed that nondiapause migrant flies would be strongly advantaged over locally overwintered postdiapause flies due to precocious reproductive maturity, broader pattern of age-specific fertility, and higher lifetime fertility.

Iridopsis panopla (Lepidoptera: Geometridae) is a defoliator of eucalyptus (Myrtaceae). Iridopsis panopla pupae were collected on a commercial plantation of Eucalyptus grandis, in the locality of Ribas do Rio Pardo, Mato Grosso do Sul, Brazil. After 18 days, the hymenopteran parasitoids Brachymeria annulata (Chalcididae) and Trichospilus diatraeae (Eulophidae) emerged from the I. panopla pupae. This is the first host record of these parasitoids from this important eucalyptus pest. Biological aspects of T. diatraeae were evaluated under laboratory conditions.

We provide a thorough historical account of the genus Pollenia Robineau-Desvoidy, 1830 (Diptera: Polleniidae) in North America through published records beginning in 1849. From this, we have gleaned insights into their presence on this continent, how they were perceived as pests, and studies of their biology to better frame current work on this genus. Further, we report on our own study of Pollenia spp. distribution across Canada from our collection of 2211 specimens that include all six North American species collected in seven provinces between 2011 and 2013. We report first provincial records for Pollenia angustigena Wainwright, 1940 and P. labialis Robineau-Desvoidy, 1863. We also discuss knowledge gaps and provide suggestions for future research.

Cassava (Euphorbiaceae), castor (Euphorbiaceae), and tropical almond (Combretaceae) have been suggested as three different possible natural diet sources for Samia cynthia ricini (Drury, 1773) (Lepidoptera: Saturniidae), a species of silkworm that is reared in Indonesia because it is able to produce good-quality silk. This research aims to study the effect of the types of diet on the survivorship, development time, and fecundity of S. c. ricini. The research was conducted by giving the three types of diet to S. c. ricini. The survival rate, development time, and adult fecundity were observed. The results showed that S. c. ricini had a high survival rate when fed on cassava and castor. However, S. c. ricini larvae died when fed tropical almond. A significant difference in the total larval development time occurred when S. c. ricini was fed on cassava and castor. Larvae developed more quickly when fed on the castor diet compared to the cassava diet. Moreover, the total development time is also faster when they fed castor. The pupal weight and fecundity of adult female S. c. ricini reared on castor were higher than those of adult females reared on cassava. This study implies that castor is the more suitable diet for S. c. ricini and cassava can be used as an alternate diet.

Nine Metarhizium anisopliae (Hypocreales: Clavicipitaceae) isolates were evaluated for efficacy against Melolontha melolontha (Coleoptera: Scarabaeidae) larvae, stability in culture, and the superior isolate used to produce an oil-in-water mycoinsecticide. The phenotypic and genotypic characters of four isolates with high virulence were evaluated for their stability after repeating 12 cycles of in vitro subculture. Repeated subculture did not affect the germination of conidia; however, the morphology of some isolates changed significantly. Three isolates lost their virulence, whereas the KTU-2 isolate remained highly pathogenic. Therefore, KTU-2 was selected as the superior isolate for mycoinsecticide production. After the conidia of KTU-2 were produced by solid-state fermentation using cracked rice as the substrate, the conidia were formulated as an oil-in-water emulsion and its efficacy was assessed. The formulation caused 80% mortality on Me. melolontha larvae even at the lowest application rate (1 × 105 conidia/mL) in pot experiments, and complete mortality was obtained with the concentration of 1 × 107 conidia/mL. Lethal concentrations that kill 50% and 95% of Me. melolontha larvae present were estimated as 9.29 × 103 and 2.1 × 106 conidia/mL, respectively. Oil-in-water mycoinsecticide could be a potential candidate for the commercial control of Me. melolontha and other white grubs.

Identifying pests associated with novel crops is important for forecasting impacts on their production and determining if they could be reservoirs of pests moving over onto cash crops. We carried out preliminary pest surveys in two bioenergy crops, carinata (Brassica carinata Alexander Braun (Brassicaceae)) and camelina (Camelina sativa (Linnaeus) Crantz (Brassicaceae)), and a cover crop mix under evaluation to replace fallow in rotations with wheat. Insect pests were sampled in each of the three crops over two years. Crucifer flea beetles, Phyllotreta cruciferae Goeze (Coleoptera: Chrysomelidae), dominated the pest complex associated with carinata and the cover crop mix, comprising more than 70% of the insects sampled. In contrast, the pest complex associated with camelina was dominated (40–91%) by generalist Lygus spp. (Heteroptera: Miridae). Crucifer flea beetles were 200–1000 times more abundant in carinata than in camelina, suggesting that they could be a serious pest of carinata. Camelina, in contrast, appears less likely to be attacked by, or serve as a reservoir for, crucifer flea beetles. Future work to assess feeding damage and population buildup of pests in these crops is needed to determine impacts on their production and the extent to which they may be reservoirs of canola pests over broader spatial scales.

The alder bark beetle, Alniphagus aspericollis (LeConte), is known to overwinter as larvae and adults in the main stems of red alder, Alnus rubra (Bongard). Observations of adult alder bark beetles in the branch and bud nodes of planted saplings during the winter led to the hypothesis that these microhabitats represent alternative overwintering sites for the beetle in mature trees. To test this hypothesis, we surveyed crown branches at three coastal British Columbia locations, sampling three trees in 2003 and 2004 and three additional trees (nine branches per tree) in 2018–2019. Adult beetles were found overwintering inside sites excavated in the branch and bud nodes throughout the crowns of mature trees. Branch type, defined by growth class, and tree affected the overall distribution and likelihood of overwintering site occupancy among the three trees sampled intensively in 2018–2019, whereas overwintering site age (old versus new (current year)) affected the frequency of site occupancy across all six trees. We suggest that overwintering in tree crowns evolved from late-summer maturation feeding in new shoots and that the majority of beetles abandon terminal shoots as temperatures fall, moving deeper into the crown to overwinter preferentially in older branch tissues that offer greater thermal protection.

Fossil insects have been collected and described from the early Eocene Allenby Formation of southern British Columbia, Canada for over a century, but these have never included Odonata. We describe the first members of that order from the formation: Allenbya holmesae, new genus and species, most likely belonging to the Dysagrionidae (suborder Cephalozygoptera), and a torn, folded, and incomplete wing assigned to the Aeshnidae (suborder Anisoptera) that cannot be identified below family level. In other regional deposits of the early Eocene Okanagan Highlands series of lacustrine shales, the Dysagrionidae is by far the most common odonate family, followed by the Aeshnidae.

Orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a major economic pest of wheat (Triticum aestivum Linnaeus). Here, we review its general biology, history of global spread, economic impact, and methods available to manage its populations. Outbreaks have been reported across the Northern Hemisphere, including in China, Japan, the European Union, the United Kingdom, the United States of America, and Canada. Predators and parasitoids can help attenuate these outbreaks, but control has relied mainly on use of foliar insecticides. Wheat cultivars with resistance to midge conferred by the Sm1 gene became commercially available in 2010 and increasingly are grown to manage midge populations. Forecasting models have been developed in different countries to predict wheat midge populations in an effort to mitigate the degree of economic damage by supporting wheat cultivar selection and to optimise the timing of insecticide applications in conventional wheat production systems. Conservation of natural enemies, insecticides, resistant cultivars, and models combine to form effective integrated pest management programmes for midge, illustrated for Canada with a decision-making flowchart. Future work is needed to address the likely development of midge biotypes with resistance to the Sm1 gene and insecticides currently in use.

In 2012, we evaluated the effects of hardwood cerambycid pheromones (syn-2,3-hexanediol, 3-hydroxyhexan-2-one, and 3-hydroxyoctan-2-one) on catches of bark and woodboring beetles in ethanol-baited multiple-funnel traps in two field trials in Oregon and Washington, United States of America. Catches of Phymatodes aeneus LeConte (Coleoptera: Cerambycidae) in ethanol-baited traps increased with the addition of 3-hydroxyhexan-2-one lures or the 3,2-hydroxyketone lure blend (3-hydroxyhexan-2-one + 3-hydroxyoctan-2-one). Catches of the predator Thanasimus undatulus (Say) (Coleoptera: Cleridae) in ethanol-baited traps increased with the addition of 3-hydroxyhexan-2-one lures but not syn-2,3-hexanediol lures or 3-hydroxyoctan-2-one lures. The 3,2-hydroxyketone lure blend decreased catches of the corthyline ambrosia beetle, Gnathotrichus sulcatus (LeConte) (Coleoptera: Curculionidae), but not the xyleborine ambrosia beetle, Xyleborinus saxesenii (Ratzeburg), (Coleoptera: Curculionidae). Catches of Ptilinus basalis LeConte (Coleoptera: Anobiidae) in ethanol-baited traps increased with the addition of the 3,2-hydroxyketone lure blend.

Wheat, Triticum aestivum Linnaeus (Poaceae), and canola, Brassica napus Linnaeus (Brassicaceae), yield is at risk from insects, weeds, and pathogens. Insects must adapt to both seasonal and annual weather patterns and are known to respond to climate with changes in their distribution and relative abundance. Subsequently, risk to crop production also changes. Models that account for multiple species can serve to assess risk and address those risks proactively by monitoring, detecting, and managing insect pests. Bioclimatic models, developed individually for nine insect pests, were used to create a model to estimate risk to canola and wheat crops associated with the activity of multiple pest species. Once developed, the multiple-species model was used to analyse how crop risk responds to variation in temperature and precipitation across the prairies. For this analysis, we compared insect response and subsequent risk (a measure of the number of co-occurring pest species) to canola and wheat in current climate conditions and six incremental scenarios (warmer, cooler, drier, wetter, cooler and wetter, and warmer and drier). Results of the multiple-species model predict how pest complexes respond to climate conditions. The model will help increase risk awareness associated with insect pests.

Cyclamen mite, Phytonemus pallidus (Banks) (Acari: Tarsonemidae), is a pest of strawberry, Fragaria × ananassa Duchesne (Rosaceae), that injures new growth, resulting in damage to leaves and fruit. The primary source of cyclamen mite in strawberry is infested planting material, and damaged plants tend to occur in small, isolated patches in perennial production systems. In the present study, we determined through repeated sampling of strawberry plants in Ontario and Saskatchewan, Canada whether relative cyclamen mite population levels were stable in commercial fields and whether overwintering and field renovation (mowing) affected populations. In Ontario, cyclamen mite counts were significantly correlated for 66% (10 of 15) of the paired comparisons from six sampling dates in more than one year, indicating a relatively stable distribution of cyclamen mite patches in strawberry fields. Winter caused high mortality (100 times fewer mites in spring than fall) and mowing caused some mortality (10 times fewer mites post- than pre-mow). We found that more cyclamen mite motiles were extracted from plant material stored in ethanol and triple-washed than were extracted using Berlese funnels, although counts from leaves were correlated between methods. No cyclamen mites were found in Saskatchewan. Knowing that cyclamen mite patches are local and spread is negligible will facilitate targeted applications of controls.

Durable materials for Nzi traps were tested in three applied settings based on promising formats that were tested first in Canada. Experiments were conducted at Cape Cod, Massachusetts, United States of America at the site of a major tabanid control programme and at two challenging tropical locations (Sudan and Philippines) where mechanical transmission of trypanosomiasis occurs. At Cape Cod, royal blue–painted plywood Nzi traps caught up to 19 times as many tabanids as greenhead box traps used locally did. Fabric Nzi traps caught up to six times more horseflies, Tabanus spp. (Diptera: Tabanidae), than a box trap did and twice as many horseflies than a popular commercial trap, the Horse Pal® did. A home-dyed phthalogen turquoise cotton trap also performed well. In the Philippines, it caught 2.5 times as many Tabanus as a standard phthalogen blue cotton trap did. Durable phthalogen blue Sunbrella acrylic and Top Notch polyester traps with various types of netting performed well at all locations.

Dung beetles (Coleoptera: Scarabaeidae (Aphodiinae, Scarabaeinae) and some Geotrupidae) provide important ecosystem services on pastures by disrupting and burying deposits of cattle dung. The extent of these services is influenced by the number of individuals and species present, which may differ with habitat type. In the present study, we compared dung beetle assemblages in a mosaic of open grassland and wooded habitats on native fescue pastures in the Cypress Hills of southern Alberta, Canada. Using pitfall traps baited with cattle dung and operated from spring through autumn for two years at each of the two sites, we collected 4944 individuals representing 14 dung beetle species. More individuals and species were recovered in grassland habitat, which was dominated by nonnative species associated with cattle dung. Wooded habitat was dominated by a native species associated with deer dung. Dwellers (species that develop within the dung deposit) comprised 93% of the beetles recovered during the study. Significant variation in annual beetle counts in the two habitats highlights the value of studies conducted over multiple years. These results emphasise the importance of habitat diversity and interspecific habitat preference in structuring dung beetle assemblages on fescue grasslands, which are among the most threatened ecosystems in Canada.

The Orthocentrinae is one of the least-studied groups within Ichneumonidae and possibly a major component of the tropical fauna, encompassing a rich but still obscure diversity. In this first attempt to uncover these biota in Brazil, we surveyed a restricted area within mountain chains in the southeastern region immersed in the Atlantic tropical forest, using several sampling methods along an elevational gradient. Using integrative taxonomy, we found a richness eight times higher than the current number of species known in Brazil, including 13 genera, of which 10 are new to the country. The 127 molecular taxonomic units found represent an increase of at least 50% in species for the Neotropical fauna, confirming the immense gap in taxonomic knowledge of this group in the Neotropics. Analyses of elevational gradient patterns of distribution indicated an increase in species elevational ranges with increasing elevation, supporting Rapoport’s rule. A key including all 14 genera occurring in Brazil is proposed, aiming to facilitate future taxonomic reviews and encourage research on this group. Orthocentrinae is a major component of the fauna and likely to be more diverse in wet lowland tropical forests; however, taxonomic and faunistic studies in tropical areas, including dry forests and savannahs, are needed.

Swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), causes severe economic losses in Brassica Linnaeus (Brassicaceae) crops in its invasive range in North America. Larvae feed within the meristem of their host plants, causing deformed heads, stems, and leaves. Pheromone-mediated mating disruption is particularly promising for swede midge management in high-value vegetable crops because its use is allowed in organic production. However, a major challenge to developing economically viable mating disruption is that the stereospecific three-component swede midge pheromone is costly to synthesise. In broccoli (Brassica oleracea Linnaeus var. italica) field plots, we tested whether stereospecific, lower-cost racemic, and single-component pheromone blends resulted in trap shutdown and reduced crop damage compared to nontreated controls. We found a significant reduction in males caught in three-component stereospecific and racemic pheromone–treated plots but not in the single-component treatments. Although marketable broccoli yields were not higher overall in the pheromone-treated plots compared with those in the controls, yields were significantly higher in the three-component stereospecific treatment in year 2. Therefore, the three-component stereospecific blend shows promise as a pheromone blend for swede midge mating disruption. However, due to high cost and levels of crop damage across all treatments, additional research is necessary to optimise swede midge mating disruption.

Nymphs and adults of Chlamydatus ruficornis Knight were collected in southeast Wyoming, United States of America, under monoculture mats of prostrate knotweed, Polygonum aviculare Linnaeus (Polygonaceae). Adults and instars III–V of this rarely encountered phyline were common in small open areas of bare dirt between overlapping knotweed stems. In captivity, adults and nymphs fed on knotweed stems and occasionally leaves but appeared to avoid inflorescences and seeds. This species is multivoltine and overwinters as eggs in the Laramie Range of Wyoming (elevation 1665 m). A key to the developmental stages of brachypterous nymphs and photographs of each instar are provided. The location of meso- and metafemoral trichobothria and the dorsal abdominal scent gland opening of the nymphal instars are described. A rare macropterous fifth instar is described and photographed.

Aphodius fimetarius (Linnaeus, 1758) (Coleoptera: Scarabaeidae: Aphodiinae: Aphodiini) sensu lato is a taxon of probable European origin common in cattle dung across North America. This species has recently been recognised as a species complex composed of A. fimetarius and Aphodius pedellus (De Geer, 1774), with overlapping distributions in North America. A previous report that only A. pedellus is present in Canada was based on examination of specimens almost solely from the United States of America. In the present study, we examined the morphology of specimens (n = 2091) from localities across Canada. In combination with DNA barcoding, our results confirm that only A. pedellus is present in Canada. Results of similarity analysis confirm reduced genetic diversity among North American specimens of A. pedellus, consistent with the hypothesis that this species was introduced onto the continent during European settlement.

Canada geese, Branta canadensis (Linnaeus) (Anseriformes: Anatidae), and mallards, Anas platyrhynchos Linnaeus (Anseriformes: Anatidae), are infested by several species of chewing lice (Phthiraptera: Menoponidae, Philopteridae). We examined the spatial distribution of lice upon these hosts. Hosts were dissected into five body regions: head and neck, wings, back, underside, and tail. Canada geese (n = 20) were infested with six species of lice. Anaticola anseris (Linnaeus) (n = 423) and Anatoecus spp. (n = 510) were restricted to the wings and head, respectively, whereas Ornithobius goniopleurus Denny (n = 1919) and Ciconiphilus pectiniventris (Harrison) (n = 757) were spread over multiple body regions. Trinoton anserinum (Fabricius) (n = 2) was present in insufficient numbers to reach conclusions about its distribution. Mallards (n = 8) were infested with four species of lice. Anaticola crassicornis (Scopoli) (n = 121) and Anatoecus dentatus (Scopoli) (n = 244) were restricted to the wings and head, respectively. Holomenopon maxbeieri Eichler (n = 52) infested multiple body regions, and Trinoton querquedulae (Linnaeus) (n = 27) were found mainly on the wings. Chewing lice infesting mallards and Canada geese partition their hosts in accordance with their own morphological and ecological requirements.