PLUM CURCULIO

COMMON NAME: Plum Curculio

SCIENTIFIC NAME: Order Coleoptera, family Curculionidae, Conotrachelus nenuphar

SIZE: Adult—1/5"

IDENTIFICATION: Adults are brownish gray weevils with warty wing covers and white hairs on the body. Short, thick, curved snout. Eggs white to gray, elliptical, laid in crescent-shaped slits in the skin of fruits. Larvae are white worms with light brown heads. Damage in fruit appears as crescent or half-circle wounds.

BIOLOGY AND LIFE CYCLE: Two or three generations a year. Adults hibernate in the soil. Larvae hatch in the fruit and tunnel within before leaving to pupate in the soil. Brown rot often follows, causing deformed fruit and premature fruit drop. Adults emerge from late July to October. Feed on ripe or fallen fruit until fall.

HABITAT: Most fruit trees and blueberry orchards.

FEEDING HABITS: Adults and larvae feed on fruit, especially cherries, plums, peaches, apricots, apples, and pears.

ECONOMIC IMPORTANCE: Damage and loss of fruit production. Wounds to fruit and premature drop.

NATURAL CONTROL: Improve soil, mulch all bare soil, and plant adapted trees. Let chickens or other grazing foul eat the dropped fruit. Mulch heavily with compost. Birds and beneficial nematodes.

ORGANIC CONTROL: Spray with Garrett Juice plus citrus and garlic. First spray should be just before bud break in the spring, second spray after blossoms have fallen, third spray in mid-season. See appendix for Fruit and Pecan Tree Program.

INSIGHT: A common pest problem in chemically grown fruit crops. Incredibly heavy chemical spray programs have been used for this pest and still haven't achieved good control. The overall organic program including the use of pheromones will control this pest quite well.

Plum curculio damage on peaches. Photo via Purdue U.
Top right photo, via Wikimedia.

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