For solitary bees, nesting substrate availability may limit population growth. Here, we investigate the nesting of a locally abundant bee Osmia conjuncta Cresson (Hymenoptera: Megachilidae) in empty shells of exotic snails, Cepaea spp. Held (Stylommatophora: Helicidae), in Hamilton, Ontario, Canada. A literature review determined that O. conjuncta was sparsely distributed throughout its range, with a low relative abundance except for the Niagara Region of Ontario, Canada, three sites in Maryland, United States of America, and the focal study area in Hamilton, Ontario. The Hamilton field survey of five grassland bee communities found O. conjuncta to be the most abundant bee species. The average relative abundance was 18.7%, peaking at 87% on one spring day. A survey of 1088 empty snail shells was done at the site with the highest O. conjuncta abundance. It revealed an average of 10.87 empty shells per square metre with cocoons in 9.8% of the shells, averaging 1.6 cocoons per nest. The relation between shell traits and cocoon presence indicated that O. conjuncta preferred nesting in shells with intermediate size and colour and avoided shells near shrubs. The presence of Cepaea snails increased O. conjuncta populations with potential consequences to the local bee assemblage.

Urbanisation has modified the distribution and community composition of mosquito species (Culicidae). Habitat disturbance may increase the risk of loss of species diversity and the occurrence of vector-borne diseases. Studies on the presence of larvae and the eco-physicochemical characteristics of water bodies near urban areas provide information on the risk of these diseases. In this study, the presence of larvae in different types of urban and periurban water bodies in Villahermosa City, Tabasco, Mexico was analysed. The eco-physicochemical characteristics of each collecting site were measured. A total of 67 528 larvae were collected, 1366 were identified to species, and 15 species were observed. Although Culex spp. were the most dominant species, Anopheles albimanus was the only species present in all habitats. Despite the large variability in the parameters measured (especially in physicochemical parameters; e.g., pH, electrical conductivity, total dissolved solids), differences were observed among the breeding sites. Weak correlations were found between eco-physicochemical parameters and species presence. Predators may have a major role in determining community processes in the region. Habitat disturbance may be responsible for eco-physicochemical variations altering mosquito community composition, resulting in the loss of endemic mosquito species and increasing the risk of vector-borne diseases in Villahermosa.

Forensic entomology is an important component of criminal investigations, providing information surrounding a death using region-specific data on the local necrophagous community. To understand the community within the Metro Vancouver region of British Columbia, Canada, a field study monitored the abundance and diversity of necrophagous Calliphoridae (Diptera) over a nine-month period in distinct terrestrial environments. Baited bottle traps (n = 9) were deployed weekly for 12-hour intervals in three different environments. Species, sex, and gravidity of collected specimens were determined. Bivariate analyses revealed significant relationships between species, geographic location, and month of collection, suggesting that Calliphoridae species composition is influenced by habitat type and seasonal shifts in temperature. Sex ratios and reproductive ranges of Calliphoridae differed among the habitats sampled.

In this study, we compared the Scarabaeinae (Coleoptera) assemblages between two contrasting habitats (conserved forest versus urban habitat), located between the boundary of an urban zone and a protected area within the Mexican state of Chiapas. We collected 1003 individuals of 22 species and 12 genera. The composition of assemblages was similar between habitats, with a high species dominance. However, the identity of the dominant species differed between habitats, with 11 species considered indicators of one of the two conditions (five species in the conserved forest sites and six species in urban habitat sites), whereas three other species exhibited generalist habits. Large paracoprids predominate in the conserved forest, and small paracoprids in the urban habitat. The apparent homogeneity in the dung beetle assemblages probably is due to the high density of domestic and feral animals replacing native mammals and is promoted by the loss of forest-dependent species caused by continuous landscape fragmentation. Nonetheless, the association of some species with forest habitat and the differences in the structure of functional groups indicate the importance of conserving these forest remnants, which would help to mitigate the negative impact of urbanised areas, as these species are generally sensitive to the habitat fragmentation process.

The forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae), is an irruptive forest pest found throughout North America. Widespread species such as M. disstria are exposed to historical and contemporary processes that are not uniform and can generate regionally distinct genomic variation. Previous analyses used a short mitochondrial fragment to infer broad-scale phylogeographic patterns in M. disstria, whereas nuclear markers have been previously applied only in a smaller geographic region. In this study, we quantified M. disstria population variation with genome-wide single nucleotide polymorphisms and cytochrome c oxidase from mitochondrial DNA. Using highly variable genome-wide markers, we resolved clear genomic differences among populations of M. disstria east of the Rocky Mountains that were not detected using mitochondrial variation alone. We also did not detect host-associated divergence in either our genomic or mitochondrial data. Our results highlight the utility of genome-wide markers to resolve intraspecific population structure within a widespread species and support the need for further biogeographic sampling of this forest insect pest.

Thirty-one species of Cinara Curtis (Hemiptera: Aphididae) are recorded from Japan, including five that are undescribed. We here formally describe one of the five, Cinara stigmatica sp. nov., from viviparous apterous females on two species of Abies Miller (Pinaceae). Morphological and molecular diagnoses are provided. Specimen data are simultaneously published in an open-access machine-readable format.

Because bark and ambrosia beetles fly during their dispersal and host location processes, their flight height is important for assessing their host selection strategy. There is no consensus regarding the height of their dispersal flight in forests, and their method of approaching trees is unclear. This is also the case for Platypus quercivorus (Murayama) (Coleoptera: Platypodinae), which causes Japanese oak wilt by transporting a pathogenic fungus. To clarify the vertical distribution of the flying population of P. quercivorus inside the host tree canopy, interception traps were set up at heights of 1–9 m from the ground near the main trunk of eight host trees, Quercus serrata Thunberg (Fagaceae). Captured beetles were collected between July and October 2022. Hole-boring activities were observed on all trees during the season, and beetles were captured at all heights from 1 to 9 m. Beetle capture probability increased with a decrease in height, and the number of captured beetles increased with a decrease in distance from the main trunk. However, the trap design in this study could not capture individuals coming directly above and must be addressed to elucidate their method of approaching their host plant.

The European root-boring moth, Chamaesphecia empiformis (Lepidoptera: Sesiidae), was released in Ontario, Canada, in 1971 and 1989 as a biological control agent for the perennial invasive weed cypress spurge, Euphorbia cyparissias Linnaeus (Euphorbiaceae). Until recently, the moth was believed to have failed to establish. Beginning in 2015, images posted on citizen science platforms, including BugGuide, iNaturalist, and Facebook groups, indicated that C. empiformis was in fact established. We have confirmed its presence in eastern Ontario by morphological and molecular identification of field-collected adults and eggs. This may be the longest-known lapse between the release of a weed biological control agent and confirmation of its establishment. Citizen science may provide valuable records documenting the establishment and dispersal of biological control agents.

Thrips (Thysanoptera: Thripidae) communities in agroecosystems are poorly known, particularly in Québec, Canada, where thrips can cause damage in strawberry crops. The phenology of anthophagous thrips and their use of cultivated and wildflower resources were monitored in strawberry agroecosystems, encompassing strawberry (Rosaceae) fields and adjacent uncultivated margins, on Orléans Island, Québec, Canada. A community comprised of 11 thrips species was described, dominated during the whole season by pest species Frankliniella tritici and F. intonsa, which is a first mention in Eastern Canada. Surprisingly, the major strawberry pest F. occidentalis was absent in our samples. Thrips species richness and abundance on wildflowers varied, with few flowering plant species supporting a majority of the community. Sampling sites and local wildflower presence influenced the thrips species assemblage observed on strawberry crops. Such a high thrips diversity was unexpected in this agroecosystem. The identified associations between pest thrips and wildflower species will be useful to develop better control programmes in strawberry crops.

The cotton bollworm, Helicoverpa armigera (Hünber) (Lepidoptera: Noctuidae), is a polyphagous pest that causes severe damage to economical crops in most parts of the world. The juvenile hormone analogues are a group of insect growth regulators that increase larval ages and disrupt larval development. Moreover, they affect reproductive system in adult insects. In this study, the effects of sublethal doses of fenoxycarb on fecundity, fertility, and longevity parameters, as well as on oocyte size, ecdysteroid titer in ovaries, and expression level of the ultraspiracle (USP), ecdysone receptor (EcR), hormone receptor 3 (HR3), and vitellogenin (Vg) genes in adult female H. armigera, were examined. Feeding on artificial diet containing fenoxycarb (LC10 and LC25) significantly decreased the percentage of larval survival rate, pupation rate, pupal weight, fecundity, fertility, and oviposition period. It also clearly shortened female longevity. Fenoxycarb treatment suppressed the expression of the USP, EcR, and Vg genes in H. armigera but had no effect on the HR3 gene expression level in either pupae or adults. Overall, our results show that using fenoxycarb as a juvenile hormone analogue can reduce reproduction in H. armigera and may work as an alternative to the use of insecticides for controlling this important agricultural pest.

We explored ecological aspects of the early establishment of the association between the Japanese beetle, Popillia japonica (Newman) (Coleoptera: Scarabaeidae), and the adult tachinid parasitoid, Istocheta aldrichi (Mesnil) (Diptera: Tachinidae), in the province of Québec, Canada. The Japanese beetle started its invasion in the late 1930s, whereas I. aldrichi was detected only in 2009. It is assumed that I. aldrichi spread in the province from its introduced range in the northeastern United States of America. Throughout the summer, we used baited traps in eight localities of southern Québec (2018–2019) and in 13 raspberry (Rubus idaeus) fields (2022) localised along a latitudinal gradient to describe the distribution and seasonal occurrence of both species and the parasitism rates of I. aldrichi. We also mapped observational data from the online platform iNaturalist to further describe the current distribution of both the host and its parasitoid. Results indicate that I. aldrichi is well spread in southern Québec and along the St. Lawrence River in most areas where the Japanese beetle is present. Parasitism mostly occurs from late June to mid-July, before the peak of Japanese beetle populations, and levels of total seasonal parasitism range from 3.9 to 27.3% across sampled sites. Together, trap captures and data from iNaturalist provide evidence that I. aldrichi is now established in most areas of the province of Québec where the Japanese beetle is present.

An accurate and efficient sampling method is an important tool for insect pest management because it allows for consistent measurements across many samples. There are currently no proposed standardised sampling plans or spray thresholds for the aphid Ericaphis fimbriata Richards (Hemiptera: Aphididae) on highbush blueberry (Vaccinium corymbosum Linnaeus) in British Columbia, Canada, despite it being the primary vector for blueberry scorch virus (BlScV). A standard sampling plan for this pest would allow for rapid and consistent measurements of aphid abundance in commercial fields and would allow for more detailed study of the relationship between aphid abundance, damage, and the spread of BlScV. Binomial sampling plans use the presence:absence of a pest within a sample unit to estimate the proportion of infested sample units. Pest density (proportion of measured samples with individuals present) is linked to abundance (number of individuals), and the relationship between these two measures can be modelled mathematically. In the present study, we collected data on aphid density and aphid abundance in six varieties of highbush blueberry grown in the Fraser Valley, British Columbia. These data were used to construct a distribution-free binomial model that, when given a measure of aphid density, can predict aphid abundance within a given sample.

The seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae), is reported as a polyphagous pest species found in numerous crops, including onion, corn, crucifers, and soy. Two morphologically identical genetic lines of D. platura (H- and N-lines) with distinct distribution ranges were recently discovered. Although many biological traits have been described for D. platura, no study to date has been conducted on the life history strategies and reproductive behaviours of its two lines. Using laboratory-reared colonies, this project investigates the effect of group composition (sex ratio and density) on the mating success and preoviposition period of the two D. platura lines. We found a substantial increase in mating success with increasing proportion of males within mating groups for both lines, whereas we found group density had negligible effects. However, the H-line had a lower average mating probability across treatments compared to the N-line. The preoviposition period decreased as the ratio of males to female increased at low density only for the N-line, and the opposite trend was observed at high density for both lines. These results suggest differences between the mating systems of these two lines, thereby highlighting the need for further research into the factors that influence their respective mating systems.

The Palaearctic ten-spotted lady beetle, Adalia decempunctata (Linnaeus), has been confirmed as established in North America, based on morphological characters and DNA barcodes. Its distribution currently appears limited to the Avalon Peninsula of the island of Newfoundland, Canada. Several characters, including the colour of the mesepimera, frons, labrum, antennal club, mouthparts, and legs, are reliable for discriminating among this species and the native, Holarctic two-spotted lady beetle, Adalia bipunctata (Linnaeus), in Newfoundland. An identification key to the two species is provided.

Dermacentor variabilis and Dermacentor andersoni (Acari: Ixodidae) parasitise the same range of hosts in western Canada and have largely allopatric ranges except for a zone of sympatry in southern Saskatchewan, where these species experience the same environmental conditions. We report herein the discovery of differences in the behaviour of D. variabilis and D. andersoni larvae after they emerge from eggs. A behavioural diapause observed in D. variabilis larvae was not detected in D. andersoni larvae that were exposed to the same environmental conditions. As unfed D. variabilis larvae can successfully overwinter, their behavioural diapause represents an adaptive strategy to synchronise their questing activity and life cycle stage to maximise the chance of larvae encountering a suitable rodent host at the onset of spring. Such strategy will be of a significant benefit for colonising individuals at the northern edge of the distributional range of D. variabilis.

Spotted-wing drosophila, Drosophila suzukii, is a global pest of soft fruits that is capable of reproducing on a wide range of cultivated and wild plant species. In Canada, D. suzukii was first reported in British Columbia in 2009 and is now widespread across the country. Understanding the genetic structure of D. suzukii populations could be important for pest management if there are phenotypic differences between genetically distinct populations. For example, insect pest populations could respond differently to directional selection imposed by insecticides, differ in their host plant preferences, and vary in their susceptibility to biological control agents. Here, we used double-digest restriction site–associated DNA sequencing to examine large- and fine-scale patterns of the genetic structure of D. suzukii reared from fruit hosts in Canada. We found that this species has a large-scale spatial genetic structure; the flies collected formed two distinct genetic clusters, one of which was distinct to western Canada and the other to eastern Canada. At the local scale, D. suzukii populations showed no evidence of host-associated structuring in British Columbia, suggesting that pest management tactics may be best applied at the landscape level. Our results highlight the need to investigate phenotypic differences between western and eastern D. suzukii populations in Canada.

The blow flies (Diptera: Calliphoridae) include many species that are important as nuisance flies, disease transmitters, and pollinators and are also very important in forensic entomology. Understanding the presence, phenology, and abundance of species in a given area is important in analysing a forensic case and is also valuable in developing baseline databases for comparison over time. Little work on Calliphoridae has been conducted in Manitoba, Canada. Baited traps were deployed at eight sites around the Winnipeg area throughout the insect season in 1978, 1979, and 1980. Five species, Cynomya cadaverina (Robineau-Desvoidy), Protophormia terraenovae (Robineau-Desvoidy), Phormia regina (Meigen), Lucilia illustris (Meigen), and L. sericata (Meigen), were regularly collected, with Calliphora spp. Robineau-Desvoidy collected much less frequently. The same species were collected consistently over the years of trapping, although abundance varied greatly even at the same sites.

A modified Nzi trap was tested at a residence and at a farm in eastern Ontario, Canada to better capture high-flying tabanids (Diptera) such as Chrysops Meigen. A new upper trap entrance was created to provide a higher and larger opening by reducing the front blue top shelf to half its height. To minimise escape of low-flying tabanids, a vertical inner baffle was added to direct low-flying tabanids up into the cone. Half of the tests of 18 new designs caught 1.5–2.7 times more deer flies than the Nzi trap did, with the other trap designs being as effective as the Nzi trap. The optimal design that maintained equal catches of other biting flies relative to the Nzi trap was one with a phthalogen inner horizontal shelf and a netting inner vertical baffle. This design is defined in the present as the “bi-level Nzi trap.” Chrysops entered the trap mostly through the top (88%; 17 spp.), along with Hybomitra Enderlein (94%; 12 spp.). Tabanus Linnaeus (9 spp.) entered through both entrances. The most abundant Tabanus, T. quinquevittatus Wiedemann, entered mostly through the bottom (70%), whereas Stomoxys calcitrans Linnaeus entered mostly through the top (92%).