Scientific Name

Sitophilus oryzae

 

Habitat

Rice weevils are usually found in grain storage facilities or processing plants, infesting wheat, oats, rye, barley, rice, and corn. Although not often found in the home, they are sometimes found infesting beans, birdseed, sunflower seeds, dried corn, and too a lesser degree macaroni and spaghetti. Rice weevils do not bite, nor do they damage wood or furniture. 

 

Life Cycle

The adult female rice weevil lays an average of 4 eggs per day and may live for four to five months (producing 250-400 eggs). A single generation can be completed in around 28 days. The eggs hatch in about 3 days. The larvae feed inside the grain kernel for an average of 18 days. The pupal stage lasts an average of 6 days (5-16 range). The new adult will remain in the seed for 3 to 4 days while it's cuticle hardens and matures. 

 

Description

Adult weevils are about 3/32 to 1/8 inch long (2-3mm). The adult rice weevil is a dull reddish-brown to black with round or irregularly shaped pits on the thorax and four light reddish or yellowish spots on the elytra (wing covers). The adult weevil can fly and is attracted to lights. The larval stage is legless, humpbacked, white to creamy white, with a small tan head. The maize weevil is very similar to the rice weevil, but larger. 

 

Control

Control of these insects involves inspection and removal of infested food products, discarding the heavily infested material, repackaging material in new containers, and vacuuming kitchen cabinets. Products that need to be retained may be placed in the freezer for several weeks to kill adults and larvae.