Strawberry Sap Beetle

Beetles are brown and have a slightly mottled appearance. In extremely overripe berries, another sap beetle, the picnic beetle, might also be found. The picnic beetle is larger and has four orange blotches on its back.

As the berries begin to ripen in May and June, adult sap beetles are attracted to the patch. They attack ripe, nearly ripe, or decaying fruit by boring into the berry and devouring a portion. On sound berries, the sap beetles usually gain entrance from under the berry, eating a hole straight into the berry. This occurs more often when the fruit is in contact with the ground or the mulch layer. The hole can be seen if the fruit is picked, but it is not usually conspicuous unless several sap beetles are working together. The adults are seldom seen because they fall to the ground and scurry away when fruit is disturbed.

The primary injuries caused by strawberry sap beetles are the cavities eaten by one or more beetles. The beetles also disseminate organisms that cause rots in the fruits and carry these to other fruits as they move about. Any damage to the berries near harvest, such as other insects attacking the fruit or mechanical injury, might stimulate an invasion of sap beetles. Larval damage is much less obvious because except in extremely serious infestations, the fruit is usually decomposed by the time the larvae are present.

Problems with sap beetles often arise with the buildup of overripe berries when rain occurs during harvest. Keep fruit picked, and remove damaged, diseased, and overripe fruit from the patch regularly.  This will assist in reducing populations, and minimize attractiveness of the patch to the beetles.