K.H.P. RathnaweeraA. M. S. L. AtapattuK. M. JayasinghaP. K. P. N. Shyamalee

Introduction

• Kingdom: Animalia• Phylum : Arthropoda• Class: Insecta• Order: Coleoptera• Family: Curculionidae• Genus: Sitophilus• Species: S. oryzaeBinominal name:Sitophilus oryzae

Habitat

• Rice weevils are usually found in, Grain storage facilitiesFood processing plantsFood markets

Morphology and structure

Adult rice weevil;• 2mm in length• Has a long snout• Dull reddish brown to black with irregular

shape pits on thorax• 4 reddish spots on elytra

Larvae;• Legless, humpbacked• White to creamy white in colour• Has a small tan head

Pupa;• White in colour• Appendages free • Segments are movable

Life cycle

Behavior

• Rice weevils are internal feeders. • The female uses her strong mandibles to

chew a small hole in a grain kernel.• Rice weevils are active fliers.

Damage

• The larva feeds within the kernel and consumes the endosperm.

• The adult leaves a large, ragged exit hole in the kernel and feeds on damaged kernels.

• The rice weevil adult gathers and reproduces in stored grains.

Damaged foods

• Rice• Wheat• Corn• Macaroni• Oats

• Barley• Sorghum• Kaffir seed• Buckwheat• Rye

Control

• Removal of infested food products.• Discarding the heavily infested material.• Repackaging material in new containers.• Vacuuming kitchen cabinets.• Products are placed in the freezer for several

weeks.• Clean bins regularly.

• Treat bins with a registered insecticide.• Properly dispose of any grain debris found

outside of the storage area.• Fumigation.• Apply insecticide.• Lower the temperature of the commodity to

at least -5°C for a minimum of 12 weeks.