The economic importance of the cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham), increased rapidly in the prairies of western Canada following its discovery in canola near Lethbridge in 1995. Since 1999 outbreaks have occurred almost annually over thousands of hectares of cropland, necessitating applications of vast quantities of chemical insecticide. Both larvae and adults can damage...

To understand how different trophic organisms in a parasite food chain adapt to the differences in soil nutrient conditions, we investigated stoichiometric variation and homeostasis of multiple elements in two acorn trees, Quercus variabilis and Quercus acutissima, and their parasite weevil larvae (Curculio davidi Fairmaire) at phosphorus (P)-deficient and P-rich sites in subtropical China wher...

The pine weevil (Hylobius abietis), a major pest of conifer forests throughout Europe, feeds on the bark and cambium, tissues rich in terpenoid resins that are toxic to many insect herbivores. Here, we report the ability of the pine weevil gut microbiota to degrade the diterpene acids of Norway spruce. The diterpene acid levels present in ingested bark were substantially reduced on passage thro...

The insecticidal activities of extracts from 22 Malaysian medicinal plant 8 botanical families were tested against rice weevil: Sitophilus oryzae (L.) and lesser grain borer: Rhyzopertha dominica (F.). obtained using hexane, methanol, dichloromethane to extract potential biopesticides dried leaves. toxicity levels examined periodically based on antifeedant activity contact assays treated assay....

Rice weevil Sitophilus oryzae (L.) is one of most serious insect pests stored grains. Management this thus vital and fumigation with phosphine gas the common method. However, overreliance on has resulted in development heritable resistance S. oryzae. The detection frequency distribution crucial for management strategy. This study assesses frequency, strength populations from four southern state...

This study aimed to explore the larvicidal and growth-inhibiting activities, and underlying detoxification mechanism of red palm weevil against phenylpropanoids, an important class of plant secondary metabolites. Toxicity of α-asarone, eugenol, isoeugenol, methyl eugenol, methyl isoeugenol, coumarin, coumarin 6, coniferyl aldehyde, diniconazole, ethyl cinnamate, and rosmarinic acid was evaluate...

The parasitoid Anisopteromalus calandrae (Howard) was very sensitive to direct contact with Protect-It, an inert dust formulation containing 90% diatomaceous earth and 10% silica aerogel. LT50s at room temperature and humidity were 49 min (95% CL 5 48Ð51) and 72 min (95% CL 5 69Ð74) for males and females, respectively, in petri dishes containing 2.5 mg dust per square centimeter. Under the same...

Studies of biogeographic variation in species abundances are fundamental to understanding and predicting the impacts of invasive exotic species. We quantified the abundance of the introduced and now invasive biocontrol weevil, Rhinocyllus conicus, on a newly adopted native host plant, Cirsium canescens (Platte thistle), across the plant's distributional range. We used regression and structural ...