San Diego Natural History Museum--Your Nature ConnectionSDNHM Field Guide
photo of Figeater Beetle

Cotinis mutabilis
Green Fruit Beetle, Figeater Beetle

SCARABAEIDAE

Description

The adult green fruit beetle measures almost 1-1/4-inch (20-34 mm). Its body is a drab green color bordered in yellow or brown from above and bright iridescent green from below. Often confused with the much smaller and destructive Japanese beetle, the figeater causes little economic damage and is not controlled in California.

Range and Habitat

From early summer through fall, the erratic and clumsy flight of this large green beetle can be seen throughout San Diego County. Not common 30 years ago, the beetles have since become very abundant, primarily due to the increased popularity of organic gardening. The beetles deposit their eggs during the fall in decaying plant material, especially in manure and backyard compost heaps.

Natural History

Control of the figeater should be attempted during the larval stage. Turning over their compost and manure hatcheries exposes the grubs to the natural predations of birds and insects. This is an inexpensive and safe alternative to chemical control.

The larval grubs feed on the organic material and develop quickly. Heat given off by the compost allows the grubs to remain active the entire year. When their feeding is disturbed, the grubs roll over on their backs and inch away, using their body segments, not legs, for traction. During the spring, underground chambers are formed by the grubs in which to pupate. Winged adults emerge a few months later.

The figeater can readily eat overripe or bird-damaged figs, peaches, and grapes, but its weak mouthparts are ineffective in ripping open most other plant material. Native plants, including plant pollen and cactus fruit, are rarely damaged initially by the beetles; they usually are found taking advantage of damage done by other insects.

David Faulkner, Research Associate, Entomology Department

Field Guide Feedback Form

Field Guide: Arthropods
Entomology Department | Field Guide