At our meeting last month, CCOG member, Karen Sheilds, gave an extensive slide presentation and group discussion on Pests in the Garden-What’s Bugging Me? We were going to post all of her information in one post, but the information was so excellent that we decided to break it up into a series of posts and do one post per pest. (Try saying that ten times in a row…one post per pest, one post per pest, one post per pest…)
Feel free to continue the conversation and add your own discoveries on pest control by leaving a comment. If you have had great success with a particular organic method, let us know what worked for you! Thanks!
Aphids, or plant lice, feed on most vegetable crops, many houseplants and many ornamentals grown in New Hampshire, as well as numerous weeds and wild plants. With their awesome reproductive abilities, aphids can build up in large numbers in a very short period of time. Depending on species, aphids feed on host plant leaves, stems, flowers and roots. They damage plants in three ways: they suck sap from their host and inject a toxin, causing the plant to wilt, yellow, and often die; they excrete a sticky substance called “honeydew,” upon which a black sooty mold can grow, diminishing the aesthetic value of the plant; some species of aphids transmit virus diseases to plants.
There are many species of aphids in NH, some of which are green, but can be almost any color. Adults aphids are soft-bodied insects about 1/16 to 1/8 inch long. Eggs are tiny, oval, black and found attached to undersides of leaves, on stems and in crevices of most host plants.
Prevention and non-chemical control:
Encourage ladybugs! Both adult beetles and larvae have enormous appetites for aphids. Also, control aphid-loving weeds, such as lamb’s quarters, in and around gardens.
If only a few plant leaves are affected, either remove the leaves or crush the aphids by rubbing infested leaves between thumb and forefinger. Directing a hard stream or spray of water at plants early in the day may remove many aphids from infested plants.
Insecticidal soap is a safe, effective control for aphids on ornamentals and vegetable crops. Horticultural oil sprays can help to control some aphids on fruit trees and ornamentals.
Some other aphicides registered for use on vegetable crops include pythrethrum, pyrethrins and malathion. If only a few plant leaves are affected, either remove the leaves or crush the aphids by rubbing infested leaves between thumb and forefinger. Directing a hard stream or spray of water at plants early in the day may remove many aphids from infested plants.
ACKNOWLEDGMENTS: The information above was gleaned from the UNH Cooperative Extension Website a GREAT resource!