Flour mill beetle
Scientific name
Cryptolestes turcicus (Grouvelle)
Classification
Primary pest; grain feeder
Order: Coleoptera
Family: Laemophloeidae
Acronym: CTU
Description
- Flour mill beetle is often confused with the flat grain beetle (Cryptolestes pusillus).
- Adults are small (1.5 to 2.0 mm), reddish brown and flattened with long bead-like antennae.
- Adults have a ridge (sublateral carina) on the head and prothorax.
- Larvae are elongate and flattened with well developed legs.
- Larvae are pale, white to yellow in colour with a darkened head capsule and dark urogomphi present.
- Larvae move actively amongst the food feeding on the endosperm or germ.
- Male antennae are longer (almost as long as body) than female antennae (half the length of the body); rusty grain beetle antennae are the same length in both sexes.
Images
Similar species
- Rusty grain beetle (Cryptolestes ferrugineus)
- Flat grain beetle (Cryptolestes turcicus)
- Foreign grain bettle (Ahasverus advena)
Commodities affected
- Flour, damaged grain
- Waste grain, cacao, spices, dried fruit, copra
Signs of infestation
- Damage is not readily identifiable as being caused by this species.
Damage
- Damage is usually restricted to grain stored under high moisture conditions.
- Both larvae and adults feed on germ and endosperm.
- Heavy infestations may cause grain to heat and spoil.
- Flour mill beetle may spread fungal spores through grain.
How to control
Geographic range
- Is found in Europe, North Africa, Japan, some South American countries and North America
- Is found across Canada
Where found
- Can survive Canadian winters only in heated structures
- Is found mainly in machinery of flour and feed mills, occasionally in grain elevators and warehouses
- Requires high temperature and relative humidity for optimal development but is cold tolerant
Life history
- Beetle’s development is favored by the presence of fungi in its diet.
- Females lay eggs in crevices or loosely amongst the food.
- Adults cannot climb up glass.
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