What Insects Eat Blackberries?

Insects like to eat blackberry plants (Rubus spp.), which grow vigorously with plenty of leaves, canes and abundant, sugar-rich fruits. Hardy in U.S. Department of Agriculture plant hardiness zones 4 through 8, different species of blackberries grow wild throughout North America, and many cultivars are available for gardens. Hardiness zones vary depending on the cultivar. Various insects feed on different plant parts, such as the underground crown, leaves, canes, flowers and fruit.

Two kinds of larval insects burrow into blackberry canes. The raspberry crown borer is a clear-winged moth that has a black and yellow banded abdomen, somewhat resembling a wasp. Young larvae burrow into canes near the soil line. Older larvae hollow out the crowns. Remove and destroy infested crowns and canes in fall or early spring. Raspberry crown borers live mainly in Northern states. A small black beetle with a coppery-red thorax or "neck," the rednecked cane borer lives in the East. The small, white larvae feed on the cambium layer of canes and produce gall-like swellings. Remove the infected canes when the vines are dormant or in early spring.

Some leaf-eating beetles in the scarab family find blackberry leaves attractive. The rose chafer, a 1/2-inch-long light brown beetle with a reddish-brown head, feeds on not only leaves but buds and flowers in the Eastern U.S. They feed for four to six weeks in spring. Handpick them when you see them. Another small scarab beetle, the metallic-green and copper Japanese beetle, is about 3/8 inch long, distributed in Eastern states. Handpick the beetles, dropping them into a container of soapy water to kill them, or set out beetle traps with chemical lures specific to Japanese beetles, placing the traps at least 30 feet away from the blackberries.

You can nearly always find some aphids, or plant lice, on the tender new growth of blackberry vines. They insert hair-like mouth parts into the stems and suck out plant sap. Usually the vines can sustain light aphid infestations without harm. Wash aphids off with strong sprays of water. Naturally present enemies may be sufficient to control aphid populations. Scale insects hide themselves under protective, crusty coverings. Slender mouth parts tap into the plants' sap-bearing tissue. Look for 1/8-inch-wide, circular white scales of the rose scale near cane bottoms. Prune out and destroy infested canes, using pruners cleaned with a cloth soaked with rubbing alcohol to prevent disease spread.

When blackberries are ripe, you'll find insect visitors. Paper wasps are fondest of overripe fruits, so keep berries harvested to reduce their visits. Stink bugs feed on the interior white receptacle at the core of each blackberry, as do leaf-footed plant bugs. Neither damages the fruit severely enough so that you can't eat it, but stink bugs can release a powerful smell that fouls the fruit if they're threatened. Stink bugs are gray, brown or green shield-shaped bugs, and brownish leaf-footed plant bugs are more slender, with flattened, leaf-like hind legs. Green June beetles, about 3/4 inch long, eat the fruits. Pick the beetles off and destroy them. A relatively new pest from Japan, the spotted wing drosophila, appeared in 2008 in California. Unlike native fruit flies, which inhabit damaged or rotting fruit, the spotted wing drosophila has a saw-like ovipositor that can lay eggs in healthy blackberries. Minimize the possibility of infestation by harvesting ripe fruit promptly and cleaning up damaged or overripe blackberries, which can also harbor the flies.