Canola, Brassica napus Linnaeus var. oleifera, is one of the main oilseeds grown in the world. Pollination is required to ensure an acceptable yield. Among the main bee pollinators (Hymenoptera: Apidae) occurring in canola in southern Brazil are Apis mellifera (Linnaeus) (Apidae: Apini) and Trigona spinipes (Fabricius) (Apidae: Meliponini). Plant genotype, sowing season, meteorological factors, and abundance of competitors can influence the foraging rate of A. mellifera and T. spinipes in canola, which will impact yield. We evaluated the effect of plant genotype, sowing season, and meteorological factors on the abundance of foraging bees, as well as their coabundance and impacts on canola yield. Under the conditions of the study, we did not observe significant variation between genotypes and sowing season on bee abundance and canola yield. We note that the impact of temperature and relative humidity are important predictors of abundance of A. mellifera and T. spinipes. The temperature and relative humidity effects, however, differed according to bee species. Coabundance patterns indicated no evidence of competitive exclusion. Higher canola yields were obtained when both bee species had high population abundance.

We examine the fossil weaver ants (Formicidae, Formicine, Oecophyllini) of the early Eocene Okanagan Highlands fossil localities of British Columbia, Canada and Washington, United States of America, naming Eoecophylla quilchenensis n. gen. et sp. from Quilchena (British Columbia), formally transferring Camponotites kraussei Dlussky and Rasnitsyn (Republic, Washington) to the genus Oecophylla Smith, F., and describing but not naming a worker (McAbee, British Columbia), treated as Oecophyllini sp. A. These are the oldest known Oecophyllini (Oecophylla + Eoecophylla) and Oecophylla. Forewing vein stubs of E. quilchenensis and its well-developed hind wing vein M are plesiomorphies; this M is unique within the subfamily, suggesting Oecophyllini is sister to other Formicine. The head shape of O. kraussei n. comb. indicates a close relationship to Oecophylla longiceps Dlussky from Eocene Messel, Germany. The ant Titanomyrma Archibald et al. is also known from the Okanagan Highlands and Messel, consistent with Late Cretaceous/early Paleogene intercontinental dispersal. We discuss possible host plants and trophobionts of these ants. Although Okanagan Highlands localities were cooler than the Paleotropical range of modern Oecophylla, their presence there might be explained by mild winters without significant frost.

Cephus cinctus Norton (Hymenoptera: Cephidae), the wheat stem sawfly, is a well-established and important pest of wheat, Triticum aestivum Linnaeus (Poaceae), and its relatives in North America. Crop losses are caused directly by C. cinctus feeding inside wheat stems during larval development and indirectly when weakened plants lodge before being harvested. Understanding the factors that affect population dynamics of C. cinctus can help farmers to better manage it. Our study therefore explored how C. cinctus and natural enemy densities vary in space (southern Alberta, Canada) and over time. Five fields were sampled using an established protocol in fall 2019 and resampled in spring 2020; six additional fields were sampled in fall 2020 and resampled in spring 2021. Wheat stubs were dissected to record numbers of cut stems, C. cinctus larvae, and sources of larval mortality (i.e., parasitism, fungal infection). Densities of wheat stem sawfly and the impact of natural enemies varied between the sampled fields. No C. cinctus mortality was observed during the winter, indicating that C. cinctus population dynamics are not susceptible to mortality (abiotic or biotic) between years. Results of our study will be incorporated into new models to predict wheat stem sawfly phenology and risk to crop production.

Parthenium hysterophorus Linnaeus (Asteraceae), commonly known as “congress grass,” is among the 10 worst weeds of India and is considered one of the world’s 100 most harmful invasive species. This species has been introduced accidentally into several countries, including India, and is a major agricultural and rangeland weed in more than 45 countries. It affects crop production, suppressing biodiversity, crop yields, the health of farm animals and human beings, and local and regional economies. Biological control has been found to be a cost-effective management strategy to control the weed, with the leaf beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), considered an effective and safe biocontrol agent. Several studies have investigated the beetle’s biology, reproduction, and other life attributes. This review compiles the existing information about Z. bicolorata biology, growth, development, reproduction, food, and host specificity, and the effects of abiotic and biotic stressors on the insect’s life attributes. We anticipate that this review will helpful for improving strategies for this bioagent’s swift mass rearing and for developing classical biological control design for Parthenium weed.

There is strong evidence that a biodiversity crisis is underway, fuelled by pollution, climate change, and invasive species. These impacts are especially important in northern Canadian regions. However, insect and other arthropod monitoring in Northern Canada urgently needed for land preservation is lacking. This paper presents the Nunavik Sentinels, a community-based participatory research programme (see definition, Table 1), that is aiming to fill those knowledge gaps while promoting collaboration among all stakeholders (organisations and members of northern communities, and scientists). Nunavik Sentinels is a unique insect-monitoring programme facilitated by the Montréal Insectarium – Espace pour la vie (Montréal, Québec, Canada), making entomology accessible to Indigenous youth by providing them with tools to lead expeditions in unexplored habitats and involving them in data collection. We present how this programme came to existence and its four-pillar framework (i.e., training land camp, summer employment, educational kit, and research). We touch upon how the programme is continually evolving. Finally, we demonstrate the benefits of the programme and how it will help better define the actions to be taken to prepare for future changes in northern biodiversity.

The functional response of parasitoids is a main component of models that describe host–parasitoid interactions. When the functional response assumed in a model (e.g., a population model) is inaccurate, predictions by the model based on the functional response also become unreliable. This study reports that conventional functional response models may commonly fail to capture the actual functional response of parasitoids and discuss its implications. To assist the discussion, an experiment was conducted to describe interactions between the pupal parasitoid Dirhinus giffardii (Hymenoptera: Chalcididae) and its host Bactrocera dorsalis (Diptera: Tephritidae) in the laboratory. Results showed that the parasitoids typically interacted with all hosts in the environment but parasitised a small fraction of them (e.g., most encountered hosts were rejected), which deviates from the assumption of mechanistic functional response models. An increasing number of published studies on functional response also suggest (although circumstantially) the rejection of unparasitised hosts is common, suggesting that this behaviour is widespread among parasitoid species. By using the experimental results, the study discusses why existing hypotheses are insufficient for the observed behaviour and the implications of this behaviour within the realm of theories surrounding host–parasitoid interactions.

Eriocampa ovata (Linnaeus) (Hymenoptera: Tenthredinidae), commonly known as woolly alder sawfly, is an introduced species to North America. Its larvae have six or more prolegs, a brown spot on the head’s vertex, and are woolly in appearance due to a wax secretion from epidermal glands. The author was contacted about six recently planted alder trees in Winnipeg and Victoria Beach, Manitoba, Canada. The trees were determined to be Alnus hirsuta ‘Harbin’ (Betulaceae) (Prairie HorizonTM Manchurian alder), a tree species that has recently gained popularity in Manitoban urban forestry. The defoliation was determined to be caused by larvae of E. ovata. This is the first published record of E. ovata in Manitoba and the first published record of E. ovata on A. hirsuta. This detection should inform pest inventories for E. ovata in Manitoba and provide the basis for a critical examination of biosecurity measures for A. hirsuta.

I review the history of forest tent caterpillar, Malacosoma disstria (Hübner) (Lepidoptera: Lasiocampidae), occurrence from 1938 to 2001 throughout Canada, with emphasis on the insect’s impact on tree mortality. I show that forest tent caterpillar routinely kills a portion of its host tree population during outbreaks. Although the proportion killed is typically small, there are some unusual conditions during which the foliage grazer can precipitate large-scale host forest declines. These decline episodes are the result of a spatially complex pattern of outbreak spread whereby successive cycles occur asynchronously enough that there is a zone of overlap where the two cycles occur in rapid succession, leading to three to six years of defoliation, triggering a nonlinear mortality response that endures through time. One of these “cycles” is typically amplified locally to an intensity that is anomalously high and nonrecurring. Defoliation events that are periodic in aggregate may thus give rise to patterns of insect-caused forest decline that are episodic. These decline events have been shifting northwards over time and have been growing in extent. The dynamics of outbreak occurrence appears to be a complex result of interacting top–down and bottom–up forces, making it challenging to predict in advance whether or not any given outbreak will exceed the threshold required to precipitate large-scale mortality.

Using aerial sketch map data spanning more than 1 000 000 km2 across Canada, I use cluster analysis to show that outbreaks of forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae), through the 20th century have occurred regularly every decade or so; however, there are two distinct aspects to the patterning of outbreaks. The dominant mode of variability is a nonrecurring pattern of singular spike anomalies, lasting just a few years, that are regional in extent but are not synchronised across the country. The regional time series derived from cluster analysis that are dominated by these singular spike eruptions exhibit extreme skewness and kurtosis, are not stationary in mean or variance, and are not amenable to classical time-series analysis. Although these regional-scale eruptive anomalies tend to occur periodically in aggregate, their central location always varies in an unpredictable manner, resulting in aperiodic local behaviour. Range-wide periodicity is thus an emergent property from asynchronous, aperiodic eruptions aggregated across regions. The second mode of variability is a low-amplitude fluctuation of weak periodicity that is weakly synchronised across the country. These observations support a hybrid cyclic–eruptive theory of outbreak occurrence that is not consistent with the simpler idea of spatially synchronised cycling.