Cabbage and Turnip Aphids
Cabbage aphid, Brevicoryne brassicae (Linnaeus); Turnip aphid, Lipaphis erysimi (Kaltenbach), Aphididae, HEMIPTERA


DESCRIPTION

Adult - Very similar in appearance, these two aphid species are pale green and, most commonly, wingless. Both species have a pair of short swollen cornicles (tailpipe-like appendages) on their abdomens. The cornicles of the cabbage aphid are shorter than the turnip aphids. The cabbage aphid is 2.0 to 2.5 mm long and covered with grayish waxy coat. The turnip aphid has no such covering and is 1.6 to 2.2 mm long.

Egg - Virtually nonexistent in the South, the eggs of these aphids are minute, ovate, and black and are laid only in the fall.

Nymph - The wingless nymphs resemble the adults in color and shape but are smaller.


BIOLOGY

Distribution - Widely distributed throughout the U.S., cabbage and turnip aphids are most troublesome in the southern states.

Host Plants - The cabbage aphid feeds primarily on broccoli, brussels sprouts, cabbage, cauliflower, collards, kale, and radish. Mustard is rarely infested. The turnip aphid typically infests mustard, radish, shepherdspurse, turnip, and watercress. It also injures other crucifers, particularly in their seedling stage.

Damage - Aphids cluster on the underside of leaves and suck sap causing infested foliage to curl, wilt, or become distorted. Some infested plants are soon killed; others grow slowly, are stunted, and produce small unmarketable heads.

Life History - In North Carolina, cabbage and turnip aphids continue to feed and breed at reduced rates throughout the winter. Collards are an important overwintering host plant. As warm weather returns, aphid activity increases. Wingless female adults produce large numbers of live progeny (50 to 100) without mating, which all develop into females. Periodically, winged females develop and fly to new host plants. Favored by moderate temperatures and dry weather, reproduction continues in this manner throughout summer. As many as 30 to 45 annual generations occur along the Gulf Coast though not quite so many are produced in North Carolina.


CONTROL

Cultural practices are helpful in avoiding aphid infestations. Plant the crop in a well-prepared, fertile seedbed to promote vigorous growth. Avoid planting near an aphid-infested crop or on land from which such a crop has been recently removed.

Chemical control of aphid infestations is often necessary. For up-to-date recommendations, consult the current North Carolina Agricultural Chemicals Manual.

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