Japanese beetle
Popillia japonica Newman, Scarabaeidae, COLEOPTERA


DESCRIPTION

Adult - The adult is a shiny, metallic-green beetle with copper-brown wing covers. There are six tufts of white hairs on each side of the abdomen near the wing covers. It is about 13 mm long.

Egg - The egg is white or cream colored, spherical, and 1.5 mm in diameter when first laid. After being in the ground for about a week, the egg begins to swell and eventually almost doubles its original size.

Larvae - The larva or grub is about 26 mm long fully grown and white to grayish white with a reddish-brown head.

Pupa - The pupa resemples the mature beetle except that legs, antennae and wings are closely folded to the body. Pupae are about 13 mm long, first pale cream in color, later becoming tan.


BIOLOGY

Distribution - The Japanese beetle was first found in the U.S. in 1916 in a nursery near Riverton, N.J. It has now spread north to Maine, south to Florida, and westward to the Mississippi. In North Carolina, this beetle is a more serious pest of burley than flue-cured tobacco.

Host Plants - Adult Japanese beetles attack 300 kinds of trees, shrubs, fruits, field crops, and garden plants. Larvae are serious pests of turf and other grass crops.

Damage - The adult Japanese beetle has become a more important pest of field tobacco in recent years. Adults sometimes migrate into tobacco fields when their favorite vegetation is scarce. Damage commonly occurs in small localized areas, usually near field borders. The beetles damage tobacco plants by eating ragged holes in the leaves. Larvae feed on grasss roots but do not damage tobacco roots.

Life History - Japanese beetles overwinter in the soil as partly grown grubs. In spring, they migrate up near the soil surface and feed on grass roots. Pupation occurs in early May in North Carolina. Adult beetles begin to emerge in mid-May but populations do not peak until about mid-July. Soon after emerging, females deposit 40 to 60 eggs in small batches 5 to 8 cm deep in the ground. Under extremely dry conditions, many eggs and larvae perish. However, during warm, wet summers populations thrive and eggs hatch about 2 weeks after deposition. The newly emerged larvae feed until cold weather forces them into hibernation. Only one generation occurs each year.


CONTROL

If present in large numbers, Japanese beetles may severely damage tobacco leaves. They should be treated when 10 percent of the plants have several leaves damaged. For specific chemical recommendations, consult the current North Carolina Agricultural Chemicals Manual.