Vegetable Crop Insect Scouting

David Owens, Extension Entomologist,

A couple of asparagus beetle eggs were observed on an emerging fern late last week. These were the only eggs found in a large field of emerging spears; no adults were found but they must have been hiding nearby. Eggs are small, cylindrical and dark colored that stick into the spear at a 90 degree angle. There are two species that feed on asparagus, the common and the spotted. The spotted is less common and the larvae feed on berries instead of foliage. The common is, well, more common. It has large white square shaped spots bordered by dark metallic blue bands. It can take a week for eggs to hatch. Feeding on spears results in scarring, browning, and hooked tips. Examine 10 plants in 5-10 different spots in a field, best on a warm, sunny afternoon when beetles are going to be most active. A treatment may be justified if 10% of spears are infested with beetles or 1-2% have eggs. Labeled products for spears include malathion, permethrin, and carbaryl.