Aphids continue to be problematic so we are still using beneficial insects as a biocontrol. Sound Horticulture is supplying us with several ravenous predatory insects. One of them is the green lacewing or Chrysoperia rufilabris. The eggs of the lacewings arrive stuck to little black tabs. They hatch quickly and the larvae are hungry! During their two to three week larval phase the lacewings can eat over 200 pests a week, earning them their nickname of aphid lion. The lacewing larvae is a versatile little biocontrol in greenhouses, field crops and orchards. Besides aphids it preys on thrips, spider mites, sweet potato and greenhouse whitefly, mealybugs, leafhoppers and the eggs and caterpillars of moths. After the larval stage the adults will live four to six weeks, feeding on nectar, pollen and honeydew. Females can lay up to 200 eggs attached to the top of a hair-like filament on the leaves and the cycle begins again.
In addition to our aphid lions, we are using other beneficial insects and also a microbial insecticide. Stratiolaelaps and Amblyseius cucumeris are both both predatory mites and they seem to be doing a great job of keeping thrips under control. The insecticide we are trying is Preferal. It's a naturally occurring fungus which infects many insect and mite pests on foliage and in the soil. The spores attach and penetrate the pests, eventually killing them. The Preferal seems to be working, although we can't seem to completely get rid of those aphids. Whether they are escaping in little hidden crevices or new aphids are constantly flying in, they really like the environmental horticulture program this year. One negative to using the Preferal is the cost. $130 for a 1 pound bag, which is only viable for one month after it's opened. So as we continue to grow our stock plants this summer, we will also continue learning new methods of care and control. That's what keeps life interesting!