Small Green Worm on Green Bean Plants

Identification

• Green bean plants are likely to get infested with the lesser cornstalk borer. The blue-green worm has brown stripes and is about ¾-inch long. The pest is the larval stage of brownish yellow to black moths with 1-inch wingspan.

Damage

• The worms tunnel and feed in the stems of infested plant under the ground. This causes girdling of major stems. Above ground symptoms include wilting and stunted growth. Plants are also deformed and buds start to wither. The entire plant often dies. The pest is most prevalent in plants growing in sandy soil and during dry weather conditions.

Management

• Keep planting area free of debris and weeds. Chemical control strategies include the use of permethrin, tefluthrin or chlorpyrifos.