If you've not seen sap beetles at a picnic, you've probably seen them in the garden or at the Farmer's Market. Sap beetles are a common pest in strawberries, raspberries, tomatoes, sweet corn and other garden fruits and vegetables. Some of their more annoying habits are feeding at the tips of sweet corn ears, inhabiting the cracks in tomatoes, eating into the end of a ripe muskmelon and literally destroying entire strawberries and raspberries. Sap beetles are attracted to all ripe, damaged or cracked produce. May. Damage is low early in the season but increases as populations increase through the summer.
Sap beetles are most troublesome from midsummer to mid-autumn.
Those early spring sap beetles spend April, May and June laying eggs near decomposing plant material. The breeding site may be something obvious such as a pile of spoiled grain, but more often the eggs are in rather inconspicuous places such as rancid sap in tree wounds or under loose bark, and under leaf litter and other accumulations of rotting vegetation. The eggs hatch into tiny white larvae that feed on the watery, fermented juices. After a brief period as a pupa in the soil new beetles emerge just in time for your picnic and fresh garden produce. What to Do There is lots of advice for managing sap beetles in the garden.