Sap (Picnic) Beetle
Adult beetles are 3/16" long and are black, or black with orange spots. The adult beetles survive the winter under plant debris along hedgerows or in fields. Eggs may be deposited in rotting fruit and on silk or in kernels at the tip of the ear. Larvae resemble tiny worms or thin maggots.
Monitoring & Thresholds:
Populations build when attracted to decomposing fruit,cull piles, or corn ears injured by birds or caterpillars. Ears with exposed tips, especially super sweet and Bt varieties, are susceptible to infestation. To prevent or reduce damage, select varieties that have good tip cover, use clean cultivation, control ear-infesting caterpillars and remove or bury decomposing fruit on a regular basis. Insecticides will not completely control heavy infestations.
For current information on production methods (including varieties, spacing, seeding, and fertility), weed, disease, and insect management, please visit the New England Vegetable Management Guide website.
Crops that are affected by this insect:
The Center for Agriculture, Food and the Environment and UMass Extension are equal opportunity providers and employers, United States Department of Agriculture cooperating. Contact your local Extension office for information on disability accommodations. Contact the State Center Director’s Office if you have concerns related to discrimination, 413-545-4800 or see ag.umass.edu/civil-rights-information.