Sugarcane Beetle
Egg - When first deposited, the smooth, white egg is oval and about the size of a pinhead. Before it hatches, it gradually enlarges until it is spherical and about twice its original size.
Larva - Ranging from 4.8 to 31.8 mm in length, the dirty white grub has a brick red head, pale brown legs, and a dark abdomen.
Pupa - The pupa is about 19 mm long and changes from white to pale brown as it matures.
Host Plants - Although the sugarcane beetle is primarily a problem on corn, sugarcane, and rice, it also infests cotton, strawberry, rose, and wild grasses.
Damage - The grubs feed on the roots of grasses; however, the adult beetles are responsible for damage to field crops. Feeding below the soil surface, the beetles chew into the outer walls of lower stalks leaving large ragged holes. Seedlings suffer the most damage and are often killed when the beetles destroy the growing point. Corn plants one meter (3 feet) or taller usually recover from sugarcane beetle injury. Damage occurs most frequently when corn is planted into a sod field or adjoining such a field. Damage occurs primarily from April 15 to June 15 in Gulf Coast states and from late April to late June in Virginia and North Carolina.
Life History - Adult beetles hibernate during the winter in the soil of well-drained sod land. Although they may become active on warm days in late fall or winter, they normally do not resume continual activity until late March or early April. After mating in the soil, females each deposit clusters of three or four eggs in earthen cells. Approximately 2 weeks later, larvae emerge and begin feeding on decaying vegetable matter. After 2 or 3 months, the mature larvae enter a 2-week pupal period. Emerging in August and September, the new generation of adults feeds for a short time before entering hibernation. One generation occurs each year.
Sugarcane beetles can also be controlled chemically. Insecticides should be recommended when corn or sorghum is planned for a sod field established for 3 or more years. For specific information concerning cultural recommendations, insecticides and rates, consult the North Carolina Agricultural Chemicals Manual.