John K. Saichuk | 1/25/2012 12:56:45 AM
Click on the links above to go to the Rice Insect Fact Sheets page or to go to the Rice Insects home page.
Common Name: Chinch bug Scientific name: Blissus leucopterus leucopterus (Say)
Chinch bugs overwinter as adults in clumps of grass and other protected areas, emerging in the spring to feed and mate on grass hosts. Adults are small (1/6-inch long), black insects with white front wings with a black spot. The pattern of black and white on the back gives the appearance of an hourglass. Adults lay eggs behind the lower leaf sheaths or in soil near roots. Eggs turn red as they mature and larvae emerge in about one week. There are five nymphal instars. Young nymphs are red with a yellow band on the front part of the abdomen. Intermediate nymphal instars are brown and tan. Last instar nymphs are black and gray with a white spot on the back. The life cycle from egg to adult takes about one month, and adults may live two to three weeks.
Damage caused by nymphs and adults: Adults and nymphs feed on the leaves and stems of rice plants, young nymphs can be found feeding on the roots below the soil line. Feeding on young seedlings causes leaves and stems to turn light brown to red in color. The plants often taken on a flame color – red at the tip. High numbers of chinch bugs can kill young plants, severely reducing plant stands. Chinch bugs tent to be more problematic in drill-seeded rice until they are protected by the application of a permanent flood.
Facts: Chinch bugs overwinter as adults in grass clumps, leaf litter, and other protected areas, before feeding and mating on grass hosts including small grains such as wheat, rye, oats and barley. As these crops mature and are harvested, large numbers of chinch bugs may move to nearby rice fields.
What should you look for: To scout for this pest, inspect foliage of un-flooded rice every 3 to 5 days from seedling emergence until application of permanent flood. During warm weather chinch bugs will hide in cracks at the soil line. Infestations often begin on the edge of a field. It is common to find the infestation beginning near a grassy ditch bank of pasture where the grass is dying. Chinch bugs will move from dying grass plants into irrigated rice fields.
How you can manage chinch bugs: There is no threshold for chinch bugs in rice. The field should be treated if high numbers of chinch bugs are present and plants are being damaged and/or killed. Cultural control: flood infested fields to kill chinch bugs or to force them to move onto rice foliage where they can be treated with an insecticide. Control weeds well before planting. If you delay weed management, you may force chinch bugs off of dying weeds and onto your rice crop.