Insects can be important yield-limiting factors in the production of soybeans in South Carolina, and numerous types of insects are capable of causing feeding injury to the crop. There are 3 major categories of pestiferous insects that affect soybeans:
Examples of these are listed below.
Some insects feed on stems or tunnel into stems (called “stem feeders”) and can cause significant injury and losses due to stand reduction, lodging, and reduced size and quantity of seeds. These insects include several important species of borers and hoppers. Most successful control measures for borers are related to cultural control methods such as crop rotation and tillage operations.
Soybean plants have a tremendous ability to compensate for feeding injury to foliage. Insects that feed on leaves (called “defoliators”) can be beetles, grasshoppers, and many species of caterpillars. Plants in the vegetative growth stages can withstand greater loss of leaf material than those in reproductive stages where blooms and pods are produced. Thresholds are based on estimates of defoliation with respect to stage of bloom.
Other insects feed primarily on the pods and seeds (called “pod feeders”) and cause direct losses to yield. Soybean podworm (a.k.a. corn earworm, bollworm, etc.) and stink bugs are frequent pests requiring control in soybeans.
Management of insects important in soybean requires some knowledge about these and other species. See “Soybean Insect Management” for more details about scouting and treatment thresholds. For specific insecticide recommendations, see “Soybean Insect Control” for suggested guidelines concerning insecticides and rates.