Aphids in Field Crops

October 18, 2015

corn leaf aphids and soybean aphids
Left: A colony of corn leaf aphids sucks sap from corn plants and deposits sticky “honeydew.” Right: By feeding with their sucking, needle-like mouthparts, large numbers of soybean aphids can reduce soybean plant vigor and growth rates.

Aphids are an insect pest that can create infestations in corn and soybeans, among other crops, including cotton and wheat. Without proper management, aphids can significantly reduce yields, grain quality and profits. Aphid damage to field crops can be attributed to virus transmission through feeding. Aphids can infect a crop with viruses almost immediately when they begin to feed and can spread the virus from plant to plant through feeding.

Several types of aphids exist among crops. The largest commonality for aphids is their ability to produce multiple generations in a single growing season through asexual reproduction. For example, in summer, the aphid population in soybeans is composed of all females that essentially clone themselves via live birth. This tremendous reproduction ability of aphids poses a significant risk to soybean production. The same is true for aphids affecting other crops.

Typically, aphids have antennae, soft bodies and as many as six segments. They may be green, black, brown, pink or practically colorless. Aphids have two compound eyes and a tail-like protrusion.

Aphids use sucking mouthparts to feed on plants and have long, thin legs. Aphids also possess cornicles, which are abdominal tubes that deposit a quick-hardening fluid called cornical wax. The wax serves as a defense mechanism.

The best approach to managing aphids is prevention, which includes cultural practices, seed treatments and foliar insecticides. Learn more about the identification, lifecycle and management of specific aphids in corn and soybeans: