How do outside-hosts-overwintering parasitoids, at the adult stage, cope with cold?

Introduction: When overwintering, most endoparasitoids are protected from the cold inside their hosts. However, some endoparasitoids, along with ectoparasitoids, fall into the category called outside-hosts-overwintering parasitoids (OHOP) at immature or adult stages. We compared the cold-hardiness capacity and strategy between adult OHOP and their hosts (HOST) by examining their supercooling points (SCP), with acclimation periods and acclimation temperatures, and their lower lethal temperatures at 50% mortality (LLT50).

Trophic Interactions of spp. (Coleoptera: Curculionidae) with Their Host Plants (Brassicaceae) and Their Parasitoids in the Agroecosystem of Quebec, Canada.

The genus 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 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 species and their parasitoids emerging from collected Brassicaceae plants in areas adjacent to canola fields and other crops in 2019 and 2020.

Landscape Effects on the Cabbage Seedpod Weevil, (Coleoptera: Curculionidae), and on Its Parasitoid, (Hymenoptera: Pteromalidae), in Canola.

The cabbage seedpod weevil (CSW), , an exotic pest accidentally introduced in North America in 1931, spread all over this continent and is now a major pest of canola crops. One of its main natural enemies in Europe, , was observed in eastern Canada in 2009. This study aimed to evaluate the landscape influence on CSW infestation and abundance and on parasitism in Quebec to understand the optimal conditions to potentially release this parasitoid in the Canadian Prairies.

Assemblage of Ceutorhynchinae Weevils Associated With Brassicaceae in Quebec (Canada) Agroecosystems.

Ceutorhynchinae Gistel (Coleoptera: Curculionidae) are a highly diverse phytophagous group of weevils in which the most species rich genus, Ceutorhynchus Germar (Coleoptera: Curculionidae), is mainly associated with Brassicaceae. Some Ceutorhynchinae, such as the invasive cabbage seedpod weevil (CSW), Ceutorhynchus obstrictus (Marsham), are important pests of cultivated Brassicaceae, and others are natural enemies of weeds and potential biological control agents. This study aims to characterize Ceutorhynchinae assemblages in canola growing regions of Quebec.

Planting of neonicotinoid-coated corn raises honey bee mortality and sets back colony development.

Worldwide occurrences of honey bee colony losses have raised concerns about bee health and the sustainability of pollination-dependent crops. While multiple causal factors have been identified, seed coating with insecticides of the neonicotinoid family has been the focus of much discussion and research. Nonetheless, few studies have investigated the impacts of these insecticides under field conditions or in commercial beekeeping operations.

Increased Acetylcholinesterase Expression in Bumble Bees During Neonicotinoid-Coated Corn Sowing.

While honey bee exposure to systemic insecticides has received much attention, impacts on wild pollinators have not been as widely studied. Neonicotinoids have been shown to increase acetylcholinesterase (AChE) activity in honey bees at sublethal doses. High AChE levels may therefore act as a biomarker of exposure to neonicotinoids.

Gregarious pupation act as a defensive mechanism against cannibalism and intraguild predation.

Coccinellid pupae use an array of defensive strategies against their natural enemies. This study aims to assess the efficiency of gregarious pupation as a defensive mechanism against intraguild predators and cannibals in coccinellid. The study was designed specifically (i) to determine the natural occurrence of gregarious pupation in the field for different coccinellid species, and (ii) to evaluate the adaptive value of gregarious pupation as a defensive mechanism against 2 types of predators (i.

Neonicotinoid-contaminated puddles of water represent a risk of intoxication for honey bees.

In recent years, populations of honey bees and other pollinators have been reported to be in decline worldwide. A number of stressors have been identified as potential contributing factors, including the extensive prophylactic use of neonicotinoid insecticides, which are highly toxic to bees, in agriculture. While multiple routes of exposure to these systemic insecticides have been documented for honey bees, contamination from puddle water has not been investigated.