Aphid, Green Peach
Winged green peach aphids have a black head and thorax and yellow-green abdomen. Wingless adults and nymphs are usually pale yellow green including the cornicles (a pair of tubes near the tip of the abdomen) but may be pink. Adults reach 2 mm long. Aphids feed on leaves and excrete a sugary, sticky substance called “honeydew” which coats fruit and fosters growth of black sooty mold fungus.
Numerous crop families (including solanacous crops, cucurbits, Brassicas, spinach and chard, and carrot families) as well as broadleaf weeds support green peach aphid. Feeding on young tissue causes curling, wilting, reduced growth, and contamination of harvested crop. The major damage caused by this aphid is the transmission of many different plant viruses. It is also a pest in greenhouses.
Green peach aphid overwinters in the egg stage on woody plants in the Prunus species, where nymphs feed in spring. Field vegetable crops are colonized in June by winged females who produce live young (nymphs), resulting in multiple generations of wingless females. Generation time from birth to reproductive adult is one to two weeks depending on temperature; each female produces 30-80 live young. If food quality declines, winged females develop and leave in search of new plants. In fall, both male and female winged aphids develop and return to woody plants to mate and lay eggs.
Begin to examine plants in early July for aphids and the presence of beneficial species. Spray only when aphids are increasing and building up to high numbers. Treat at five to seven-day intervals, if aphid numbers exceed 10 per leaf before fruit set, and 5 per leaf after fruit set. Coverage of underleaf surface is important. Add a spreader-sticker. Plant crops away from Prunus sp. (peach, wild cherry, etc.). Spray effectiveness may vary depending upon the species present. Reflective plastic mulch repels aphids as long as 50% of the surface area is reflective. Even black plastic mulch has been shown to reduce aphid numbers compared with bareground culture.
Aphids are usually controlled on peppers by natural predators and parasites, such as lady beetles, lacewings, spiders, syrphid fly larvae, wasps, and beneficial fungi, unless the populations of these beneficials are disrupted by chemical sprays. Preserve natural enemies by using selective/microbial pesticides for other pests whenever possible. Occasionally green peach aphid (GPA) or, less commonly, melon aphid (MA) and potato aphid (PA) populations build up and require controls. Early-season, broad-spectrum sprays will destroy beneficials and lead to aphid population buildup.
For Current information on production methods (including varieties, spacing, seeding, and fertility), weed, disease, and insect management, please visit the New England Vegetable Management Guide website.
Identifying and Enhancing Natural Enemies in Vegetable Crops
Insects
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