|Spotted Cucumber – Southern Corn Rootworm Beetle – Diabrotica undecimpunctata howardi |
Family Chrysomelidae – Leaf Beetles
Beetles Main | Beetles Index | Longhorns | Soldier | Blister | Lady | Scarab
Injury to corn and sorghum occurs in the seedling (6 to 9 leaf) stage of plant development.
This beetle has filiform antennae with 11 antennomeres (segments)
|Both the larval and adult stages are considered major agricultural pests, attacking not only cucumbers and corn, but soybeans and sweet potatos as well. Soil application of insecticides to control corn rootworms represents one of the largest uses of plant protection products in North America.|
Description: The adult is about 1/4-inch long, yellow-green with a black head and antennae. There are twelve black spots on the wing covers (elytra). The larva (rootworm) is cream colored and about 3/4-inch long when fully developed, with a brown head capsule and bearing three pairs of short legs. Life Cycle: Adult beetles overwinter and become active in the spring, feeding on a wide variety of host plants including weeds and grasses. They lay eggs in the soil. Eggs hatch in 5 to 11 days and young larvae crawl through the soil and feed on roots of corn, sorghum or other hosts. Larvae develop through three stages (instars) in 10 to 16 days before pupating and then emerge as adults after 5 to 12 days. Thus, the development takes 20 to 39 days, depending on soil temperature.
Habitat and Food Source(s): Chewing adult beetles and larvae (rootworms). Injury to corn and sorghum occurs in the seedling (6 to 9 leaf) stage of plant development. Larvae chew along roots, excavating grooves and tunnels. Often, the larvae tunnel directly into the base of the stalk, stunting plant growth or killing entire plants, thereby reducing plant stands and yield. Adult beetles feed on a wide variety of plants including leaves and flowers of vegetables (beans, cucurbits) and ornamentals. This is one of the most common beetles found in the home garden and flower beds.
Order Coleoptera: Beetles are the dominant form of life on earth: one of every five living species is a beetle. Coleoptera is the largest order in the animal kingdom, containing a third of all insect species. There are about 400,000 known species worldwide, ~30,000 of which live in North America. Beetles live in nearly every habitat, and for every kind of food, there's probably a beetle species that eats it.
Beetles Index | Longhorns | Leaf Beetles | Soldier | Blister | Lady | Scarab