Pepper Weevil
Anthonomus eugenii cano, curculionidae, coleoptera


DESCRIPTION

Adult - About 3 mm long, this reddish-brown to black snout beetle has a long curved beak. The body is covered with yellowish and gray scale-like hairs which give the beetle a brassy luster. A spur is located on the inner side of each front leg.

Egg - The oblong-oval egg is about 0.8 mm long. It is white when first deposited but gradually turns yellow.

Larva - When newly hatched, the legless larva is white and about 1 mm long. As it develops, the grub becomes grayish-white with a pale brown head and darker mouthparts. When fully grown, the cylindrical, somewhat curved larva is about 6 mm long.

Pupa - White when newly formed, the 3- to 4-mm-long pupa darkens as it matures. It has short bristles on the back of its head, prothorax, and abdomen.


BIOLOGY

Distribution - From Mexico, the pepper weevil has spread into Texas, New Mexico, Arizona, California, Florida, and Georgia. Infestations in the Carolinas and Georgia usually result when weevils are inadvertently transported on plants with small fruits or picking sacks from areas such as Florida. This pest is occasionally found farther north.

Host Plants - Pepper weevils and their grubs can develop on black nightshade, eggplant, and bell, sweet, pimento, tabasco, and chili peppers. Though weevils will feed on the foliage of several other weeds and crop plants, they do not lay eggs or develop on any of these other hosts.

Damage - The weevils feed externally on foliage, blossom buds, and tender pods. However, they do not cause as much damage as larvae which feed within buds and pods. Infested buds and blossoms fall from plants. The larvae usually feed at the seed core, but occasionally tunnel in the walls of pods. Infested peppers are black inside and filled with frass. Infestations usually are not noticed until the stems of young peppers yellow, wither, and cause the fruit to drop. By the time a few fallen pods are noticed, serious damage has occurred already and many more pods can be expected to fall in the following 10 days. Some infested pods turn red or yellow prematurely and may become malformed before dropping to the ground.

Life History - Pepper weevils spend the winter on live pepper or nightshade plants in warm areas of southern California, Texas, and Florida. They spread from their overwintering sites each spring by flying or hitchhiking on pepper plants, picking sacks, or fruit on its way to market. The specifics of their life history have not been studied in North Carolina so the following information is based on the weevil's biology in Florida.

Pepper weevils complete one or two generations on black nightshade weeds in early spring. They migrate to pepper as soon as plants become available. By June, weevils usually are feeding and laying eggs. Females make holes in buds and fruit, place eggs within them, and seal the holes with brownish fluid. Each female deposits about 200 eggs over a 30-day period. Depending on the temperature, eggs incubate in 3 to 5 days.

Larvae bore into pepper pods and feed for about 8 to 10 days. At this time, full-grown larvae create cells made of frass within peppers and pupate. Four to 6 days later, a new generation of beetles emerges. This 2- to 3-week life cycle is typical in summer. In cool weather, however, 5 to 6 weeks may pass from the egg to the adult stage. In Florida, 5 to 8 generations are produced each year.


CONTROL

The chance of an infestation can be reduced by not buying pepper plants grown in areas where the pepper weevil is a problem. A number of cultural practices help control weevil populations in areas where this pest is common and lives year round; however, such measures are of no benefit in North Carolina since the weevil cannot overwinter here. For up-to-date chemical recommendations, consult the current North Carolina Agricultural Chemicals Manual.

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