Rice Weevil, Sitophilus oryzae
The rice weevil is a serious pest of stored rice, wheat, barley and other grains. It is originated in tropical climate. Recently it is has distributed in temperate countries.  The rice weevil often known as “snout weevils,” penetrates and feed on the internal portions of whole grains during the larval stage. They are usually found in grain storage facilities or processing plants, infesting wheat, oats, rye, barley, rice, and corn. The rice weevil is closely related to the maize weevil.

Biology of Rice Weevil, Sitophilus oryzae
Rice weevil has characteristic chewing mouthparts at the end of their snouts or prolonged heads. Female rice weevils lay between 300-400 eggs, with the life cycle requiring about 30-35 days for completion. The adult rice weevil is a dull reddish-brown with round or irregularly shaped pits on the thorax and four light spots on the wing covers.  The rice weevil larvae are legless, humpbacked, creamy white, with a small, tan head.

The pupa stage has snouts like the adults. Rice weevil adults live 3-6 months, infesting grain in the field. Two larvae can develop in one wheat kernel. The egg, larva, and pupa stages of both weevils occur in the grain kernels and are rarely seen. Feeding is done within the grain kernel, and adults cut exit holes to emerge. Females drill a tiny hole in the grain, deposit an egg in the cavity, then plug the hole with a gelatinous secretion. The egg hatches into a young larva which bores toward the centre of the kernel, feeds, grows, and pupates there. New adults bore emergence holes from the inside, then leave to mate and begin a new generation

Rice Weevil, Sitophilus oryzae Nature of 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. This produces heat and moisture which can lead to mould development and invasion by other insect species

Rice Weevils monitoring
Russell IPM manufactures and supplies pheromone lure, traps and complete monitoring systems for Rice Weevils. The Xlure-MST monitoring trap provides early Rice Weevils warning also alert the pest controller before the infestation become serious.

The Maize Weevil and Granary Weevil monitoring  

The maize weevil, Granary weevil and Rice weevils are very closely related species. The maize weevils are mostly found on stored maize and causing damage to maize carnal. The granary weevil is common in cool climatic conditions. Both maize weevil and granary weevil have chewing mouthparts at the end of their snouts or prolonged heads. The multispecies trap, Xlure MST trap can be used successfully to monitor maize and granary weevil infestations.