Sawtoothed grain beetle

Classification

Primary pest; grain feeder
Order: Coleoptera
Family: Silvanidae
Acronym: OSU

Description

• Adults are small, brown, slender beetles, about 3 mm in length with serrated sides on pronotum.
• Adults are very similar morphologically to merchant grain beetle; may be separated from merchant grain beetles based on the width of the temple (narrower in merchant grain beetle).
• Larvae are white to pale yellow and flattened.

Similar species

• Merchant grain beetle (Oryzaephilus mercator)
• Foreign grain bettle (Ahasverus advena)

Commodities affected

• Affects oats (beetle is most often found here), wheat, barley, animal feed, flax, sunflower
• Affects milled and processed products, dried fruit, packaged foods
• May attack a wide variety of foods found in homes, but this may be misidentification of O. Mercator (merchant grain beetle)

Signs of infestation

• Severe infestations can cause grain to become overheated contributing to further damage.
• Beetles are capable of rapid population buildup in large bulks of grain in heated buildings.

Damage

• Damage is generalized and not necessarily identifiable as coming from this particular species.
• Both adults and larvae may feed on grain dust and larvae preferentially feed on the germ.

How to control

• Control grain insect pests

Geographic range

• Is found worldwide and across Canada.

Where found

• Is found in granaries, warehouses, elevators and food mills
• Is not able to feed on sound kernels, but is able to attack even slightly damaged grain
• Is one of the most common grain feeding insects found in grain stored on Canadian farms.

Life history

• Pupation occurs either freely or within a cocoon consisting of particles of grain.
• This species requires high temperatures, but it can tolerate low relative humidity.
• Sawtoothed grain beetle is more cold-hardy than the merchant grain beetle.
• Species is able to survive Canadian winters in unheated structures.

Video

• Video of Sawtoothed grain beetle