Get out your vermicomposter. It seems using worm compost in your vegetable garden will significantly cut down on damage by sucking and chewing insects like aphids, mealy bugs and caterpillars. Scientists are certain why the worm compost helps, but we always knew it couldn’t hurt.
Battle Bugs With Worm Compost
Greenhouse trials were conducted at Ohio State University to determine the effects of vermicompost (worm compost) on some common insect pests of vegetables. In the trials, 40 percent, 20 percent, or zero vermicompost (derived from food waste) was added to a commercial potting soil in which tomato, pepper, and cabbage seedlings were grown. The seedlings were then exposed to pests: Adult aphids (Myzus persicae) or mealy bugs (Pseudococcus species) were added to the tomato and pepper cages, while cabbage caterpillars (Pieris brassicae) were added to the cabbage cages. The average number of aphids and mealy bugs on pepper seedlings decreased significantly due to additions of vermicompost (regardless of percentage). The average number of mealy bugs on tomato seedlings also decreased significantly with additions of vermicompost. Average cabbage plant loss (based on leaf area) due to caterpillars was significantly reduced with additions of vermicompost. The OSU researchers concluded that vermicompost results in major suppression of sucking and chewing insects. Though not sure why vermicompost helped suppress pest populations, they speculated that it might contain essential nutrients not present in the potting soil that could make the seedlings more stress resistant, less attractive to the pests, or perhaps both.
Source: N.Q. Arancon, P.A. Galvis, and C.A. Edwards, "Suppression of Insect Populations and Damage to Plants by Vermicomposts," Bioresource Technology 96(10), July 2005, 1137–42 (Elsevier, P.O. Box 211, 1000 AE Amsterdam, The Netherlands).
Reprinted Courtesy of Brooklyn Botanic Garden
“Plants and Garden News”, Spring 2006