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The genus Ceutorhynchus Germar (Coleoptera: Curculionidae) is composed of canola pests, natural enemies of Brassicaceae, and other species associated with non-crop and non-weed plants. This study aimed to establish trophic associations of Ceutorhynchus with their host plants and with their parasitoids in the agricultural landscape, in order to assess the actual beneficial or noxious ecological roles of the insects. Trophic associations were established by identifying Ceutorhynchus species and their parasitoids emerging from collected Brassicaceae plants in areas adjacent to canola fields and other crops in 2019 and 2020. Five Ceutorhynchus species were collected and identified as hosts of parasitoids in the families Pteromalidae and Eulophidae. Two functional groups were characterized: natural enemies of weeds and agricultural pests. The exotic wormseed wallflower, Erysimum cheiranthoides was identified as a new host plant of the invasive canola pest Ceutorhynchus obstrictus (Marsham), and the native tower rockcress, Arabis glabra, as a new host plant of the native Ceutorhynchus neglectus Blatchley. Association between the exotic Ceutorhynchus typhae (Herbst) and a parasitoid of the genus Elachertodomyia is reported for the first time. Finally, Ceutorhynchus neglectus and C. typhae hosted the exotic parasitoid Trichomalus perfectus, an important natural enemy of C. obstrictus.

Macrosaccus morrisella (Fitch) is a tiny leaf-mining moth native to North America. In this publication, we provide first reports of this insect feeding on soybean, Glycine max (L.) Merr., in Canada and the United States, describe its injury to soybean, and briefly review leaf miners associated with soybean. Further efforts related to M. morrisella should focus on its geographic extent of infestation of soybean, impacts to soybean, and ecology in the agricultural landscape.

Caliroa dionae Smith and Moisan-De Serres, n. sp., is described from Quebec. The species was reared from larvae feeding on highbush blueberry, Vaccinium corymbosum L. (Ericaceae) and is the first North American record of a species of Caliroa feeding on Vaccinium. It is distinguished from other North American Caliroa species and from Palearctic species of Caliroa that feed on Vaccinium.

Nematus spiraeae Zaddach, a European sawfly that feeds on Aruncus diocus (Walter) Fernald (Rosaceae), was discovered in Quebec. This probable introduction is the first report of N. spiraeae in North America and the first record of a sawfly feeding on Aruncus in North America. A diagnosis and some life history notes are given for N. spiraeae.

Honey bees depend on flower resources (nectar and pollen) to supply individual and colony needs. Although behavioural studies already assessed optimum foraging patterns of bumblebees, honey bees foraging behavioural patterns have been poorly assessed. We used Sysirinchium palmifolium L. (Iridaceae), a low-growing, abundant and anthophilous grassland flower to test the hypotheses that Apis mellifera workers would i) spend more time, ii) visit a greater number of flowers, and iii) travel greater distances within patches of S. palmifolium which were newly opened or not been visited by other pollinators when compared to foraging on patches that were available to pollinators during its whole blooming period (only one day). In two different sunny days, we measured bee activities in an area opened for visitation during the whole anthesis (OP plot treatment) and another opened for visitation only half of anthesis (CL plot treatment). We observed bees spending more time, visiting more flowers and travelling more in S. palmifolium CL treatment than the OP plot treatment. Previous studies already showed bees alter their foraging behaviour in the lack of resources. Honey bees are able to remember the period of the day when resources are usually the higher, they probably detect the most promising period to gather resources on S. palmifolium flowers. Since A. mellifera is a pollinator with a wide-distribution and is considered an important cause of changes on native pollinator communities, we support additional studies evaluating its foraging behaviours to better understand how it explores flower resources.