Squash bugs and squash vine borer found in Michigan
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Squash bug eggs have been found on vine crops in many areas of Michigan. Squash bugs feed on the leaves and, later, the fruit of squash and pumpkin plants. They suck plant sap, causing wilting and fruit collapse. Adults are 0.5 to 0.75 of an inch long and grayish-brown. Nymphs are wingless and pale green to white with brown heads. Eggs are laid in clusters on the underside of leaves.
Large nymphs and adults are extremely difficult to control. (see photo) Therefore, growers must control them when eggs are being laid. Small nymphs are less mobile than larger nymphs and tend to stay in small groups. Adults and larger nymphs are very mobile and move quickly throughout the entire field. This habit, in combination with the foliage associated with an older squash or pumpkin field, means that controlling adults or large nymphs is virtually impossible. Growers should be scouting fields now and applying insecticides, if necessary.
Squash vine borer moths have been caught in pheromone traps in southwest Michigan. This is another pest that must be controlled when eggs are being laid and larvae are hatching. See the June 28 Vegetable CAT Alert for more details on squash vine borer control.