Merchant grain beetle

Classification

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

Description

• Adults are small brown slender beetles, about 3 mm in length.
• Adults are very similar morphologically to sawtoothed grain beetle. May be separated from sawtoothed grain beetles based on the width of the temple (wider in sawtoothed grain beetle).
• Larvae are white to pale yellow and flattened.

Similar species

• Sawtoothed grain beetle (Oryzaephilus surinamensis)
• Foreign grain bettle (Ahasverus advena)

Commodities affected

• Prefers foods with high oil content such oatmeal, bran, rolled oats, brown rice
• Will also feed on processed cereals, dried fruit, seeds
• Feeds on flour, cake mixes, pasta, cookies, nuts, coconut, puffed rice, pet food

Signs of infestation

• Damage is not readily identifiable as being caused by this species

Damage

• Damage is generalized and not necessarily identifiable as coming from this particular species.
• Both adults and larvae feed readily causing damage.
• In dwellings, they are normally carried into the house with food.
• In apartment buildings, they sometimes migrate, spreading from unit to unit and become a chronic pest.

How to control

• Control grain insect pests

Geographic range

• Is distributed throughout Canada

Where found

• Is primarily a problem in homes
• May be an issue where grains with high oil content are going out of condition

Life history

• Females lay up to 200 to 300 eggs over a 3-month period.
• Pupation occurs either freely or within a cocoon consisting of particles of grain.
• This species requires high temperatures and can tolerate low relative humidities.
• This species is not particularly cold tolerant.
• It does not survive Canadian winters in unheated structures.