Polydrusus weevils are a very common genus of beetles that start showing up on all sorts of plants and trees this time of year. While there are some native species of these beetles, two invasive species from Europe are most prevalent in Minnesota. The weevils can occur in large numbers on a wide variety of fruit and nut crops, but are generally benign as they feed on leaves and not flowers or fruit. Click the link below to read more about these weevils and what crops they could show up in. Polydrusus weevils - UMN FruitEdge Author: Hailey Shanovich - Department of Entomology Graduate Student
Author: Annie Klodd, UMN Extension Educator - Fruit Production. kloddann@umn.edu & Marissa Schuh, IPM Extension Educator, mschuh@umn.edu A week of warm Minnesota weather has brought with it a harbinger of spring - asparagus. For some growers, this has also brought asparagus beetles. Let’s talk about whether to use an insecticide, what to spray, and how often. Asparagus beetles feed on spears and ferns. Photo: Whitney Cranshaw, Colorado State University, Bugwood.com First Question: Do I actually need to spray? The threshold for asparagus beetles are: 5-10% of plants are infested with adults or larvae 2% of spears have eggs. Asparagus beetle eggs are laid single-file in a line. Photo: Annie Klodd, UMN Extension. Second question: What do I spray? Using insecticides in asparagus is a challenge because of the constant picking. Any product that you do use needs to have a short Pre-Harvest Interval (PHI). This varies with each product. For example, Entrust (active ingredient