Source: University of Missouri

Over the past four to five years, numbers of corn earworm (soybean podworm) have gradually increased in many of Missouri's soybean fields. Larvae may feed on numerous crops including the pods, seeds and occasionally flowers of soybean. This insect is a major pest of soybean in many southern and eastern states and traditionally has been an occasional pest of soybean in Missouri's "Boothill" counties and other counties bordering Arkansas. In 2010, infestations of podworm larvae could be found in many late planted fields throughout southern and western Missouri.

Most fields with economic podworm infestations were almost exclusively planted after June 1, 2010. These late fields are most attractive to migrating moths as females prefer to lay eggs in fields where soybean plant canopies remain open. Wind direction and the intensity of moth flights during moth migration both help determine the location and intensity of developing podworm larval infestations. Another factor that may allow podworm populations to increase to economic levels is the application of early season foliar insecticides and fungicides. 

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