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Granary Weevil
(Sitophilus granarius)

Description: Cylindrical, shiny red-brown to black body, about 1/13” - 1/8” long; long head with distinct snout; ridged wing-covers, thorax marked with oval pits; flightless; cold tolerant.

Life Cycle: Minimum 28 days

Feeding Habits: Adults feed on whole and broken kernels; larvae grow from eggs deposited inside kernels.

Signs of Infestation: Live adult weevils, and damaged grain with “shot hole” appearance.

Control Tips: Clean and treat empty bins with a tank mix of Diacon® IGR PLUS and PBO-8® Synergist; monitor grain throughout storage period; use grain protectants to help suppress insect populations; fumigate if grain is found to be infested upon receipt or shortly afterward; aerate grain during warm weather periods of storage to help control moisture and temperature.

Product Recommendations: Combination of Diacon® IGR, Centynal EC Insecticide and PBO-8® Synergist or Diacon® IGR PLUS and PBO-8® Synergist.

Application Tips: When treating flowing grain on belts or at transitions, 2 or more nozzles are recommended; during auger or conveyor cup application, fewer nozzles may be used; position nozzles for full coverage of grain stream; avoid spraying onto sides of auger boots. Calibrate protectant flow rate and check often to help ensure proper application. Use automated switches to turn chemical pumps on when there is grain in the system and turn off when no grain is present.

Overhead view of a Granary Weevil. A Granary Weevil against a ruler, it measures 1/8th of an inch.

Recommended Products

Diacon IGR Family Product Shot

Diacon® IGR

Diacon® IGR is approved virtually everywhere stored product insects are a problem. Diacon® IGR interrupts the life cycle, providing long-term control.

Centynal EC Insecticide

This stored grain insecticide can be used in empty grain bins/silos and on grain to knockdown weevils and other pests to prevent bugs in grain.
PBO-8 Synergist Family Product Shot

PBO-8® Synergist

A synergist for many classes of insecticides, PBO-8® works by blocking production of mixed-function oxidase enzymes. 
Diacon IGR Plus Family Product Shot

Diacon® IGR PLUS

This stored grain insect control contains an adulticide and insect growth regulator for quality grain protection to help get rid of weevils and other pests.
Tank Mix Options

Tank Mix Options

Applying a tank mix to your stored grains helps provide control of stored product insects.