There are over 350 different aphid species in Colorado, but most are plant specific. They vary in color from very pale yellow to almost black. Most common are green, orange and sometimes red in color. Their soft body structure make them easy prey for insects who feed on them and target for effective insecticide absorption. Colonies are made up of winged and wingless forms and both may be present on the plant. The wingless form take on the job of reproducing. When colonies get overcrowded, plant quality declines or change in environment causes them to find a new plant host. When temperatures warm up, an infant aphid will grow and develop into a mature reproductive adult in about 72 hours. This one reason their populations can increase and get out of hand in the landscape so quickly.
Common on trees, shrubs, and garden ornamentals. Aphids feed by sucking sap from a plants new leaf growth. When populations are severe the damage can cause wilting, leaf curling, and dieback of shoots and buds. The sticky honeydew (aphids waste material) is an attractant for ants, yellow jacket wasps, flies, and bees which can be as much a nuisance as damage done to the plant itself.
Mechanical – syringing (rinsing with bursts of water from hose end sprayer) and handpicking
Biological – (natural enemies) Lady beetles, specifically the larvae who have voracious appetites aphids, larvae of green lacewings, flower (syrphid) flies, and a species of minute stingless wasps who parasitize aphids. Parasites or predators are usually available at Creek Side Gardens and also through mail order suppliers.
- Fertilome Horticultural Oil Spray RTS (mineral oil) or Natural Guard Horticultural Oil RTS (vegetable oil) – softest
- Bonide Captain Jack’s Dead Bug (spinosad) or Natural Guard Spinosad Soap (spinosad + insecticidal soap) – softer, natural
- Bonide Eight Insect Control Garden & Home (lambda-cyhalothrin), – effective chemical control
- Fertilome Triple Action Insecticide/Fungicide/Miticide (pyrethrin & neem oil) – Big Guns!