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Australian Wildlife

  Rice Weevil (Sitophilus oryzae)





Rice Weevil | Sitophilus oryzae photo
Rice Weevil

Image by USDA-ARS-GMPRC Image Database - License: Public Domain.    (view image details)

Rice Weevil | Sitophilus oryzae photo
Rice Weevil pupa

Image by USDA-ARS-GMPRC Image Database - License: Public Domain.    (view image details)







RICE WEEVIL FACTS

Identification
The Rice Weevil is a small dark brown weevil with a long snout, and small round dimples on the thorax and ridges along the wing covers. There are two paler reddish brown patches at each end of the wing covers (four spots altogether). The head and thorax is nearly as long as the wing covers. It is similar to the Granary Weevil (Sitophilus granarius) which is slightly larger and has plain brown wing covers and oval dimples on the thorax. The Granary Weevil is wingless whereas the Rice Weevil has wings and can fly. The larvae are white or creamy white grubs with a small light brown head.

Size
length 2.5mm to 3.5mm

Habitat
The are often found in grain storage plants and processing plants, but are not often found in the home.

Food
The Rice Weevil is a serious pest of grain in the tropics and subtropics. It attacks cereal grains such as rice, wheat, corn, oats, maize, barley, sorghum, and also processed cereal products.

Breeding
The female weevil bores a tiny hole in the grain kernel and deposits an egg inside. The larva develops and pupates within the grain kernels and is rarely seen. The adult weevil emerges from the pupa and cuts an exit hole to emerge. The exit holes of the Rive Weevil are smaller than those of the Granary weevil, and are smoother edged.

Range
The Rice Weevil is originally from Asia, but is now found around the world as a pest species transported in grain.



Classification
Class:Insecta
Order:Coleoptera
Family:Curculionidae
Genus:Sitophilus
Species:oryzae
Common Name:Rice Weevil

Relatives in same Genus
  Granary Weevil (S. granarius)
  Greater Rice Weevil (S. zeamais)