John K. Saichuk | 1/25/2012 12:16:11 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: Colaspis spp. Scientific name: Colaspis brunnea and Colaspis louisianae
There are two species of COLASPIS in Louisiana rice: Colaspis brunnae and Colaspis louisianae. This pest can be found damaging fields of dry-seeded rice in a soybean-rice rotation. Colaspis will complete a single generation in soybeans, lespedeza or pasture. The larvae of colaspis will overwinter in the soil. The larvae will feed on the roots of a plant, such as rice, when it is planted into a field infested with the developing insect. The larvae will pupate in the soil and emerge as adults. Adults are oval in shape and about ¼-inch in length. They are a light golden color with white/gold stripes down their back and long antennae. Adults do not lay eggs on rice, but will most likely travel to a near soybean field.
Damage caused by larvae: Damage is often concentrated in field high spots. Larvae will feed on the roots of a plant, such as rice, when it is planted into a field infested with the developing insect. Feeding on fine root hair may result in plant death. It is common to find a clumped distribution of larvae in the field, resulting in patches of missing plants. It is typically easier to visualize damage in a drill-planted field than in a field where seed is broadcasted and covered.
Facts: Colaspis spp. larvae will overwinter in the soil. When rice is planted into a field that is infested with colaspis larvae, the larvae will begin to feed on the roots of the plant which may result in plant death.
What should you look for: To scout for this pest, locate plants that are stunted, withering, dying and surrounded by declining plants. Dig around the base of the plants, carefully peeling back the soil and looking for white grubs with brown heads, being slightly larger than rice water weevil larvae. Pupae or adults may also be found in the soil (see scouting video).