Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is an invasive pest of many small and soft fruits. We present the first results concerning its oviposition in the canopy of a sweet cherry (Prunus avium Linnaeus; Rosaceae) orchard. We examined the distribution of arthropods emerging from fruits of five cultivars ripening successively over seven weeks, in interior and border rows, within four regions of the tree canopy (top/bottom height × north/south aspect), and measured the associated fruit ripeness (ºBrix). Single fruits were reared for more than two weeks: 1328 arthropods emerged from 887 cherries in June, and 10 426 emerged from 1071 cherries in July. When populations were low, significantly more D. suzukii were present in the northernmost row and northern canopy aspect. Later, its distribution with respect to cherry row, height, and aspect was homogenous. Drosophila suzukii density per sweet cherry was highest in the latest ripening cultivar, when its distribution was not homogeneous; significantly more D. suzukii were in the centre than the southernmost row, in the lower canopy, and the southern aspect, than elsewhere. In the early season, single egg clutches were found without aggregation. As population density increased, so did intraspecific aggregation, but D. suzukii did not co-exist with other Drosophila Fallén species, nor with Rhagoletis indifferens Curran (Diptera: Tephritidae) when present.

Plant proteinase inhibitors are among the promising biopesticides which are induced in plants tissues against the several Lepidoptera pests to inhibit digestive proteases. In this study, protein extracts of two nonhost plant seeds, Amaranthus retroflexus Linnaeus (Amaranthaceae) and Cuminum cyminum Linnaeus (Apiaceae), were examined on Helicoverpaarmigera (Hübner) (Lepidoptera: Noctuidae). The results obtained by using azocasein as a substrate showed that inhibitory activity of general proteases of the larvae fed on a diet incorporated with both inhibitors was dose dependent. Seed extracts of A. retroflexus and C. cyminum at the highest concentration showed that inhibition activities of chymotrypsin-like proteinase and trypsin-like proteinase were between 31–45% and 28–61%, respectively. Based on polyacrylamide gel electrophoresis, all of the proteinase isoforms, including those of A. retroflexus seed extracts, disappeared entirely, and only one band was detected in the seed extracts of C. cyminum. Larval mortality in the larvae fed on A. retroflexus and C. cyminum seed extracts was 56 ± 2.15 and 68 ± 2.23, respectively, but mortality in control (no seed protein extract) was 12 ± 2.34 individuals. Also, the life table parameters were affected significantly by A. retroflexus and C. cyminum protein seed extracts. Therefore, A. retroflexus and C. cyminum seed protein extracts showed inhibitory effect on H. armigera digestive proteinases and adverse effects on survival and fitness of the pest; hence, they could be introduced as a successful biopesticide in the near future.

The annual abundance of chewing lice (Phthiraptera) was recorded on great horned owls (Bubo virginianus (Gmelin), Aves: Strigidae) from 1994 to 2015 in Manitoba, Canada. Kurodaia magna Emerson (Amblycera: Menoponidae) had a mean annual abundance about half that for Strigiphilus oculatus (Rudow) (Ischnocera: Philopteridae). Mean intensity, rather than prevalence, explained the variation in annual abundance. Temporal variation (measured as population variability) in abundance and mean intensity were high and similar (0.62–0.67), but lower for nymph to female ratio (0.36–0.38). Temporal variation of prevalence and sex ratio were higher for K. magna (0.34–0.35) than for S. oculatus (0.21–0.22), and typical for other louse species. The high temporal variability for abundance and mean intensity suggest lower year-to-year stability than exhibited by other chewing lice, but over 80% of this variability was due to sampling error resulting from small sample sizes in some years and extreme intensities in the aggregated distributions of intensity. The remaining variation, < 20%, revealed no significant differences in annual abundance or mean intensity among years, and therefore stable populations over 22 years. Populations of 12 species of chewing lice show lower temporal variability and therefore greater stability than three other insect taxa.

Eriococcus spurius (Modeer) (Hemiptera: Eriociccidae) is a pest of American elm (Ulmus americana Linnaeus; Ulmaceae) trees in western North America, but no effective biological control agent has been reported. This study took place in Calgary, Alberta, Canada, where urban American elms have been heavily and negatively impacted by E. spurius. Although the parasitoid Coccophagus gossypariae Gahan (Hymenoptera: Aphelinidae) was recovered from an E. spurius infested American elm in Calgary, little is known about its ecology. Prior to implementing biological control, the basic ecology of a candidate species must be understood. We documented the geographic establishment, sex ratios, and parasitism rate of C. gossyparaie on its host within the study area. Coccophagus gossypariae had established at 89% of study trees sampled and accounted for 98% of the parasitoids caught. They had a female-biased sex ratio of 13.7 females per male, and both males and females developed to maturity using the host. We found evidence of a highly consistent aversion to superparasitism by females in the field. This first investigation established a baseline of information on field populations of C. gossypariae that could lead to biological control of E. spurius.

The invasive alien Scolytus schevyrewi Semenov (Coleoptera: Curculionidae: Scolytinae) was detected in Saskatchewan and Manitoba, Canada, in 2007. Because S. schevyrewi is a potential vector of the Dutch elm disease pathogen (Ophiostomanovo-ulmi Brasier; Fungi: Ophiostomataceae), the natural history of the beetle was studied from 2009 to 2012 in the two provinces, where the disease is managed to protect Ulmus americana Linnaeus (Ulmaceae). Typically, healthy trees become infected when their xylem is contacted during feeding by spore-bearing scolytine adults that have flown from a diseased tree; adults emerging from brood galleries in diseased trees frequently carry spores. We caught flying S. schevyrewi adults from May to October; adults were weakly attracted to healthy Ulmus Linnaeus but were strongly attracted to Ulmus pumila Linnaeus stressed by girdling. Scolytus schevrewi colonised and completed development in girdled trees and trap logs of U. pumila. In contrast to other studies, U. americana – the major source of pathogen spores in the area – was never colonised as a brood host. Our results suggest that S. schevyrewi will primarily use U. pumila, which, in Manitoba and Saskatchewan, seldom exhibits symptoms of Dutch elm disease. Thus, arrival of S. schevyrewi does not appear to require changes to Dutch elm disease management programmes.

This study recorded distribution and size of alfalfa weevil (Hypera postica (Gyllenhal); Coleoptera: Curculionidae) populations in Saskatchewan, Canada, from 2001 to 2014. The spread of alfalfa weevil across the province, originally southwest to southeast, was northward and westward during this time. By 2014, only northwestern and west central areas remained relatively alfalfa weevil free. From a minor pest in 2001, the alfalfa weevil increased to be the principal insect pest of alfalfa (Medicago sativa Linnaeus; Fabaceae) in 2014. The parasitoid Bathyplectes curculionis (Thomson) (Hymenoptera: Ichneumonidae) had a similar distribution. Other parasitoids collected included Oomyzus incertus (Ratzeburg) (Hymenoptera: Eulophidae) and Microctonus colesi Drea (Hymenoptera: Braconidae). Conservation of these parasitoids is an important step in maximising their effectiveness as alfalfa weevil biocontrol agents. Molecular sequencing of the DNA barcoding region of specimens identified morphologically as B. curculionis indicated moderately high levels of sequence divergence among specimens (up to 5.8%); however, interspecific genetic variation between other species of Bathyplectes Förster was also high. Therefore, we conclude that B. curculionis was the only Bathyplectes species collected in our study. An illustrated key to the described species of Bathyplectes in North America is provided, as well as DNA barcodes of most species, including five distinct barcodes in the Bathyplectes curculionis–B. exiguus (Gravenhorst) species complex.

Nearly 65 years ago, D.G. Harcourt developed the first of 74 life tables of the diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), on the Central Experimental Farm in Ottawa, Ontario, Canada and at nearby sites. This work is cited whenever authors discuss the life history of the diamondback moth and its parasitoids in Canada. Since Harcourt’s study, climate change, urbanisation, and crop diversity may have altered the population dynamics of both the diamondback moth and its natural enemy community in the original study area. To follow up on Harcourt’s work, we used two approaches to build life tables to describe mortality factors in the field and the natural enemies attacking diamondback moth in Ottawa: destructive sampling of mature cabbage, Brassica oleracea Linnaeus (Brassicaceae), plants similar to Harcourt’s approach and a modern sentinel-based approach with an enemy exclusion cage treatment. After 65 years, the primary parasitoids attacking diamondback moth remained the same, although more parasitoid diversity was revealed by the destructive sampling technique. Total mortality and parasitism levels also remained similar. In one notable difference, we attributed more diamondback mortality to predation. Overall, however, diamondback moth population dynamics have changed little in Ottawa in the decades since Harcourt’s studies.

Native to southeast Asia, the spotted-wing drosophila (Drosophila suzukii (Matsumura); Diptera: Drosophilidae) has become a major pest of small fruits in the Americas and Europe. Field studies were conducted over a two-year period (2015–2016) in cultivated highbush blueberry (Vaccinium corymbosum Linnaeus; Ericaceae) fields and adjacent non-crop habitats containing wild blueberries in New Jersey (United States of America). We tracked seasonal changes in D. suzukii adult abundance and fruit infestation throughout the ripening period (June–August). In both years, D. suzukii adult counts post-harvest were generally higher in traps located in non-crop habitats compared with those located in highbush blueberry fields. Wild and cultivated fruits synchronised in maturation, and the numbers of eggs laid and of emerged adults in both fruit types were comparable for most of the season, although sometimes these numbers were higher in wild fruits post-harvest. Overall, immature success (measured as the per cent egg-to-adult survival) was also mostly higher in wild than in cultivated fruits. Altogether, these studies document that non-crop habitats, and wild hosts therein, are used by D. suzukii during fruit ripening and may serve as potential sources of infestation to nearby highbush blueberry fields. Hence, methods that reduce D. suzukii populations in non-crop habitats may help manage this pest in neighbouring highbush blueberries.

Parthenium hysterophorus Linnaeus (Asteraceae) is a toxic weed found abundantly in major agroecosystems of the world. The weed is inhabited by both phytophagous Chrysomelidae (Coleoptera), used as biocontrol agents, and the predaceous Coccinellidae (Coleoptera). The present investigation was designed to assess the feeding attributes and larval development of Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae) in the presence of semiochemical tracks of coccinellid beetles. Results revealed that the presence of coccinellid semiochemical tracks on the weed reduced larval consumption rates, conversion efficiencies, and growth rates. The feeding deterrent effects of the semiochemical tracks were species specific. Larvae accumulated lower concentrations of glucose, proteins, and triacylglycerols and exhibited reduced body biomass in the presence of semiochemical tracks. The coccinellid semiochemical tracks also promoted Z. bicolorata larvae to accelerate their developmental rates and develop faster than the larvae reared in the absence of semiochemical tracks. While the fourth instars consumed food maximally and were heavier, their food use efficiencies were lower than the other instars. Our findings, therefore, suggest that the presence of semiochemical tracks of coccinellids on P. hysterophorus impedes its biological control by Z. bicolorata larvae.

Most studies about the European earwig Forficula auricularia L. (Dermaptera: Forficulidae) assume that four larval moults occur from hatching to adult. In this note, we use observational and quantitative approaches to reveal the presence of an additional intermediate moult occurring immediately after egg hatching. We then briefly discuss how this finding may open up new possibilities for follow-up studies to improve our general understanding of the taxonomy, biology, and evolution of this species.

The identity, richness, and abundance of true flies (Diptera) from the nests of three cavity-nesting raptors (Aves) were investigated in northern Nova Scotia, Canada. After fledging, flies were extracted from the nest material using Berlese funnels within an emergence chamber. Thirty-one species/morphospecies from 14 families were collected, including eight new records for Nova Scotia and two new records for eastern North America.

The characteristics of the juvenile developmental environment of an individual can have many important consequences for their adult reproductive success as it may shape the development and expression of phenotypes that are relevant to the later operation of sexual selection. Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an economically important invasive pest species that lays its eggs in many types of soft fruits and potentially experiences large intrapopulation spatial and temporal variation in its nutritional developmental environments. Here, we examine whether the larval nutritional developmental environment influences D. suzukii mate choice, egg production, and offspring performance. Using D. suzukii raised on diets differing in their nutritional quality, we examined mating preferences, fecundity, and offspring survivorship in “no-choice,” “female choice,” and “male choice” reproductive contexts. We found evidence for both adaptive and nonadaptive mate choice behaviours associated with the phenotypes of D. suzukii that had developed in different nutritional environments. These results reveal the complex nature of the relationship between the developmental environment and individual reproductive success in D. suzukii, which has important potential implications for future management plans involving this species.

The dynamics of interactions amongst natural enemies are central to the investigation of insect pest ecology. Ternary and quaternary interactions between parasitoids and predators in the presence of entomophagous organisms are yet to be comprehensively explored. We investigated the performance of a clone of green peach aphid (Myzus persicae (Sulzer); Hemiptera: Aphididae), raised on savoy cabbage (Brassica oleracea Linnaeus; Brassicaceae), under all possible combinations of: I) the parasitoid Aphidius colemani Viereck (Hymenoptera: Braconidae); II) the predator Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae); III) the predator Adalia bipunctata (Linnaeus) (Coleoptera: Coccinellidae); and IV) the spider Parasteatoda tepidariorum (Koch) (Araneae: Theridiidae). We demonstrate a considerably differential green peach aphid abundance, polyphenism, and fine-scale spatial distribution in response to the combination, number, and identity of the present enemy species and their interactions. Surprisingly, certain combinations led to thriving green peach aphid populations due to interference between enemies; whereas, other combinations resulted in tangible collective suppression of the population. At the frontier of agroecology and entomology, we provide fresh insights on the effects of conflict and synergy between natural enemies sharing a pest of a cash crop as prey, highlighting the consequences of the presence of a novel synanthropic spider, as a top predator, on pest regulation.

Bald eagles (Haliaeetus leucocephalus (Linnaeus); Accipitriformes: Accipitridae) from 92 locations in Manitoba were examined for chewing lice (Phthiraptera: Amblycera and Ischnocera) from 1992 to 2017. Bald eagles were salvaged from rehabilitation hospitals and were examined using two methods, dry-ruffling (n = 107) and washing (n = 40). We collected 39 066 bald eagle lice of four genera and six species: Colpocephalum flavescens (De Haan), C. napiforme (Rudow), C. turbinatum (Denny) (Phthiraptera: Menoponidae) (total for all Colpocephalum species = 18 082), Craspedorrhynchus halieti (Osborn) (Phthiraptera: Philopteridae) (n = 49), Degeeriella discocephalus (Burmeister) (Phthiraptera: Philopteridae) (n = 20 912), and Kurodaia fulvofasciata (Piaget) (Phthiraptera: Menoponidae) (n = 23). Quantitative data were collected on all genera with the comparison of washed to dry-ruffled. Colpocephalum flavescens and D. discocephalus dominated the louse populations, with similar prevalence and mean intensity. Both genera had sex ratios near 1.0, and similar nymph-to-female ratios near 3:1. The dry-ruffling method was relatively inefficient, collecting 11% as many lice as the washing method. Total prevalence for dry-ruffled birds was 63%; total mean intensity was 103.5, but for washed birds, the prevalence was 93% with a mean intensity of 861.1. No Laemobothrion vulturis (Fabricius) (Phthiraptera: Laemobothriidae) were found.

Analysis of food webs is important for defining functional components of ecosystems, but dietary data are often difficult to obtain and coarsely characterised. We compared three methods of rainbow trout (Oncorhynchus mykiss (Walbaum); Salmoniformes: Salmonidae) and prickly sculpin (Cottus asper Richardson; Scorpaeniformes: Cottidae) gut content analysis: traditional morphological taxonomy of prey items, genetic sequencing of individual prey items, and next-generation sequencing of homogenised gut contents. Prey analysis of invertebrates by morphological identification allowed order-level classifications and produced ecologically important count and mass data. Sequencing individual specimens provided greater taxonomic resolution, while next-generation sequencing of stomach contents revealed more prey diversity in the diets of both fish species as it was possible to detect prey that were degraded beyond visual recognition. Both fish species exhibited generalist feeding characteristics; however, terrestrial Insecta were a large diet component for rainbow trout. This study demonstrates an efficient approach for prey analysis using molecular techniques that complement traditional taxonomy.

Engelmann spruce, Picea engelmannii Parry ex Engelm. (Pinaceae), in the southern Rocky Mountains is composed of two distinct phloem monoterpene chemotypes that differ in relative abundances of multiple monoterpenes, particularly α-pinene and Δ3-carene (hereafter, the “α-pinene chemotype” and the “Δ3-carene chemotype”). Here, relative toxicity of these chemotypes is tested on spruce beetle (Dendroctonus rufipennis Kirby) (Coleoptera: Scolytinae), a phloeophagous herbivore that colonises trees of both types. Synthetic monoterpene blends representing each chemotype were tested across a range of concentrations (0, 10, 50, 100, 200, and 500 µg/L) in the lab, and probability of survival of adult beetles exposed to each blend was modelled using a logit function. Logit curves were solved to determine LC25, LC50, and LC75 of each monoterpene blend. On average, probability of beetle survival was lower when exposed to the Δ3-carene chemotype than when exposed to the α-pinene chemotype. However, both chemotypes were completely lethal to beetles at concentrations exceeding 100 µg/L. Adult body mass did not affect survival probability. It is concluded that spruce phloem chemotypes may differ in their toxicity to spruce beetles, with potential consequences for patterns of host-tree colonisation by spruce beetle.

The role of spiders (Arachnida: Araneae) in biological control programmes has received less attention than that of insect natural enemies. The aim of this two-year study was to obtain descriptive data on spider spring field population structure and dynamics. The study was carried out in one insecticide-free and four organic apple orchards in southeastern France. Rolls and bands of corrugated cardboard near the ground and shoots infested with Dysaphis plantaginea (Passerini) (Hemiptera: Aphididae) in the tree canopy were used to sample spiders. Thirty-three spider species belonging to 14 families were identified from both sampling methods. Cheiracanthium mildei Koch (Araneae: Cheiracanthiidae) was clearly the predominant arboreal spider species in aphid-infested shoots (>57%). More than half of the spiders recorded in cardboard bands belonged to three species Drassodes pubescens (Thorell) (Araneae: Gnaphosidae), Pseudeuophrys erratica (Walckenaer) (Araneae: Salticidae), and Icius hamatus (Koch) (Araneae: Salticidae). Salticidae (39.9%) and Gnaphosidae (23.4%) families dominated significantly the spider assemblages observed in the cardboard rolls and were present on almost all sampling dates. However, in the two shelter types, the spider abundance curve clearly had a poly-modal shape. This may be due to the sequential arrival of some spider species or their dominance in a certain period of our study.

A comprehensive biovigilance programme was undertaken in 2018 to monitor potential insect vectors of viruses of grapevines (Vitis vinifera; Vitaceae) in two vineyards in Québec. Two hundred seventy-four insects were collected using yellow sticky traps and sweeping nets. Collected specimens were first classified into orders, with special attention given to the Hemiptera order, which is the main group of virus vectors. Hemipteran pests were identified to species. Among these specimens, one adult of Rossmoneura tecta McAtee (Hemiptera: Cicadellidae) was identified, the first report of this species in Canada. Empoasca vincula DeLong, Erythroneura acuticephala Robinson, and Erythroneura cymbium McAtee, three other species belonging to the same family and previously reported in other Canadian provinces, were also identified for the first time in Québec. Further investigations are being undertaken to test the ability of these species to transmit grapevine viruses.

The apple leaf midge, Dasineura mali (Kieffer) (Diptera: Cecidomyiidae), an invasive alien pest established for many years in Nova Scotia, Canada, has invaded Ontario and British Columbia, Canada apple (Malus domestica Borkhausen; Rosaceae) orchards, damaging growing tips of trees. Molecular analysis indicated that Nova Scotia populations are genetically different from Ontario and British Columbia populations. Pheromone trap captures, oviposition on growing apple terminals, and the incidence of third instars indicate three D. mali generations in each province. Platygaster demades Walker (Hymenoptera: Platygastridae), released in Nova Scotia in 1993, parasitised 34% of the third midge generation in that province and was reared from D. mali for the first time in 2016 in the Fraser Valley of British Columbia. Lyrcus nigroaeneus Ashmead (Hymenoptera: Pteromalidae) parasitised up to 21% of D. mali in southwestern Ontario. Synopeas myles (Walker) (Hymenoptera: Platygastridae) was recorded from D. mali for the first time, one specimen in each of Nova Scotia and Ontario, and was the most important parasitoid in British Columbia. Synopeas myles parasitism in Okanagan and Similkameen, British Columbia orchards increased from 0% to a mean of 30% of D. mali larvae from 2014 to 2016. Other minor parasitoids included Platygaster tuberosula Kieffer (Hymenoptera: Platygasteridae) in all three provinces and Aphanogmus vicinus Förster (Hymenoptera: Ceraphronidae) in British Columbia.

The insect commensal microbiota consists of prokaryotes and eukaryotes. We explored the effect of diet and the persistence of the gut microbiota across generations in Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). We transferred subsets of a single population of D. suzukii to different fruit-based diets (blueberry (Vaccinium Linnaeus; Ericaceae), raspberry (Rubus Linnaeus; Rosaceae), and strawberry (Fragaria × ananassa Duchesne; Rosaceae)) for three generations and then returned them to a common, banana-based, diet. We used 16S rDNA (Bacteria) and ITS (internal transcribed spacer; Fungi) sequencing of female endosymbiont-free flies to identify the microbiota. We identified 2700 bacterial and 350 fungal operational taxonomic units (OTUs); there was no correlation between the number of bacterial and fungal OTUs in a sample. Bacterial communities were dominated by Proteobacteria (especially Acetobacteraceae); Ascomycota dominated the fungal communities. Species diversity of both bacteria and fungi differed among diets, but there were no differences in species-level diversity when these D. suzukii were returned to a control diet. A principle coordinates analysis revealed no differences in the bacterial or fungal community in the first generation on fruit diets, but that the communities diverged over the next two generations; neither fungal and bacterial communities converged after one generation on control food. We conclude that diet changes the D. suzukii microbiota, and that these changes persist for more than one generation.