David Owens, Extension Entomologist, owensd@udel.edu
Asparagus
Scout for asparagus beetle adults and eggs on emerging spears. Eggs are small, cylindrical and dark colored. They 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.
Greenhouses
Be sure to scout greenhouses for signs of two spotted spider mite and aphids. Two years ago, I had aphids attack my melon transplants in the greenhouses, and last year spider mites were observed on melon transplants in greenhouses. Mitigating spider mites before they are planted in the field will save time and expense later in the season.