Sawtoothed Grain Beetles
Stored-Product Pest—Sawtoothed Grain Beetle
Size
Sawtoothed grain beetle adult is 1/8 in (2.5-3 mm) long; mature larva less than 1/8 in (3 mm) long.
Characteristics
Adult has flattened body, 6 saw-like teeth on each side of prothorax. Length of region directly behind the eye is more than half the vertical diameter of the eye. Wings are present, developed, but this insect is not observed flying. Mature larva is long and fairly smooth, antennae with 3 segments (2nd segment the longest, 3rd segment very small).
Color
Adult is brown. Mature larva is yellowish white.
Where
Sawtoothed grain beetles are found around the world.
Habitat
Home is food. Food is home!
Diet
Foodstuffs, including grains, cereals, bread, pasta products, dried meat, dried fruit and nuts, sugar, chocolate, candy, tobacco products and drugs.
Biology
The sawtoothed grain beetle female lays shiny white eggs singly or in small clusters in crevices in food material during a 2-5 month period. Depending upon temperature, the eggs hatch in 3-17 days. The larva goes through 3 molts, and makes a cocoon using food particles glued together with a sticky substance from its mouth. The cocoon hangs by its rear end from a solid object. Warm temperatures (86-95 degrees F/30-35 C) and 70%+ relative humidity may result in as many as 6-7 generations per year. Adults live about 6-10 months, but may live longer than 3 years.
Damage
Destruction of stored materials in homes and in grocery stores.
Invasion
The flat body of the sawtoothed grain beetle allows it to enter food containers and poorly sealed packaging through very small cracks.
Detection
1. Inspect stored products for adult and larval forms of sawtoothed grain beetle.
2. Adults are not known to fly, and are not attracted to the light.
Prevention
1. Inspect incoming items.
2. Supply ventilation.
3. Keep buildings in good physical condition to reduce entry.
4. Quickly remove spilled grain.
5. Keep facility and grounds generally clean.
6. Store pallets 18 inches away from walls.
7. Replace torn packages.
8. Rotate food and nonfood stock. Rotate oldest stock out first.
Control
1. Identify species correctly.
2. Use light traps and/or electrocuters.
3. Fumigate if appropriate.
4. Use insect pheromone and/or baited monitoring devices.
5. Heat to 125 degrees F (52 C) for 1 hr, or cool to 0-5 degrees F (-18 to -15 C) for 24 hours, to kill all stages.