Cowpea Aphid, Aphis craccivora
(Hemiptera: Aphididae)

The cowpea aphid is a serious pest in temperate and tropical areas and is found throughout the United States. Sexual reproduction is not required and overwintering normally occurs in greenhouses and in warm regions. The nymphs are black and lightly dusted with a whitish wax, resulting in a gray appearance. Adults are dark colored; the appendages are whitish with black tips. Adults are commonly shiny black with a fine dusting of white powder. This glossy appearance distinguishes them from the bean aphid. Adults may be winged or wingless.

Vegetable crops that are commonly attacked include asparagus, carrot, cowpea, kidney bean, lettuce, and lima bean. Weeds that serve as alternate hosts include dandelion, lambsquarters, pigweed, shepherd's purse, dock, goldenrod, and pepperweed. The cowpea aphid colonizes various plant tissues including stems, pods, and leaves, but the stems are preferred. The aphid removes plant sap, resulting in an abnormal growth pattern. The aphid does not produce toxins, and normal plant growth will resume once the aphids are removed. The principal damage caused by this species of aphid is disease transmission. The cowpea aphid is capable of transmitting over 30 plant viruses. Cowpea aphid populations can be monitored using sampling techniques such as sweep nets and visual inspections. Insecticides are commonly used to protect crops and both systemic and contact insecticides are available. In some cases, host plant resistance may also be used to prevent damage by the cowpea aphid.

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Cowpea aphid, Aphis craccivora, nymphs on hairy indigo.
(Photographer: P. Choate, University of Florida)

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Cowpea aphid, Aphis craccivora, wingless adult and nymphs
on bean.
(Photographer: P. Choate, University of Florida)

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Cowpea aphid, Aphis craccivora, winged adults on bean.
(Photographer: P. Choate, University of Florida)

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Cowpea aphid, Aphis craccivora, winged adult and nymphs
on bean.
(Photographer: P. Choate, University of Florida)

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