Sap beetles, also known as picnic beetles, are primarily scavenging insects that feed on overripe or damaged fruits and vegetables and other decaying matter. Usually they are attracted to ear tips damaged as a result of corn earworm, European corn borer, fall armyworm, raccoon damage, or bird feeding However, the beetles may enter undamaged ears anytime from early silk to maturity. Sap beetles are about 3/16 to 1/4 inch long and brown to black. There may be orange markings on the wing covers. Larvae may be found in some ear tips along with adults. These pests are difficult to control because even if large numbers are killed, more are likely to come in from untreated areas. Since these insects are scavengers, anything that can be done to prevent or eliminate overripe, insect- or disease-damage will be helpful. Insecticides used to control corn earworms should be a relatively good job of reducing sap beetle problems.
Cultural: Clean cultivation with the prompt removal of vegetative refuse is useful. Select sweet corn cultivars with good tip coverage and tight husk leaves. It is also important to maintain effective control of other ear
feeding insects, birds and raccoons. Tips of ears that are exposed and/or damaged will attract sap beetles.
Monitoring: Treat when necessary.
Ambush 2 E (permethrin)- Apply as a foliar treatment at 6.4 to 12.8 fl oz per acre to a limit of 76.7 fl oz per acre per season.
Asana XL (esfenvalerate)- Apply as a foliar treatment at 5.8 to 9.6 fl oz per acre to a limit of 96 fl oz per acre per season.
Baythroid 2 (cyfluthrin)- Apply as a foliar treatment at 0.8 to 1.6 fl oz per acre to a limit of 10 applications per season.
Diazinon 14 G (diazinon)- Apply as a foliar treatment at 7 to 14 lb per acre.
Pounce 3.2 EC (permethrin)- Apply as a foliar treatment at 4 to 8 fl oz per acre to a limit of 48 fl oz per acre per season.
Sevin 80 WSP (carbaryl)- Apply as a foliar treatment at 1-1/4 to 2-½ lb per acre to a limit of 8 applications per acre per season. Allow at least 7 days between sprays.
Warrior 1 E (lambda-cyhalothrin)- Apply as a foliar treatment at 2.56 to 3.84 fl oz per acre per season to a limit of 3.84 pt per acre per season.