khapra beetle
(Trogoderma granarium Everts, 1898)

Overview

Origin

Trogoderma granarium is native to an area extending from Burma to West Africa. Its northern most range extends to the 35° parallel and to the equator to the south.

Life Cycle

Mated females live 4-7 days, while unmated females live from 20-30 days. Males live 7-12 days. Adults have wings but do not fly. Adults feed very little. Mating occurs about five days after emergence. Egg laying is temperature dependent, beginning immediately at 104°F (40°C), but is delayed by a few days at cooler temperatures. No eggs are produced at 68°F (20°C). Females lay an average of 50 to 90 eggs which are loosely scattered in host material. Eggs hatch in 3 to 14 days. Complete development from egg to adult varies from 26 to 220 days and is dependent on temperature, with optimum temperature for development at 95°F (35°C). If the temperature falls below 77°F (25°C) for a period of time or if larvae are very crowded, they may enter diapause. Larvae can survive temperatures below 17.6°F (-8°C). In diapause, larvae can molt but are inactive and can remain in this condition for years. Development can occur at a relative humidity as low as 2%.

Distribution

Trogoderma granarium was first found in California in 1953. A massive control and eradication effort began which cost an estimated $15 million. Isolated infestations have been found in several states including California, Maryland, Michigan, New Jersey, New York, Pennsylvania, and Texas.

Control Efforts

Inspections at ports and other entry points are important to keep this pest out of America. Eradication programs use fumigants, surface sprays and heat treatments to kill Trogoderma granarium.

Resources

• Data Sheets on Quarantine Pests - European and Mediterranean Plant Protection Organization

Selected Images

Maps

Invasive Listing Sources

• Idaho Invasive Species Act
• Invasive Species of Concern in Georgia
• National Cooperative Agricultural Pest Survey Target Species
• Ontario’s Invading Species Awareness Program Tracked Species List
• Pests not known to occur in the United States or of limited distribution
• South Carolina Plant Pest List
• To be proposed for MISC
• USDA APHIS Regulated Pest List

References