Flour mill beetle Cryptolestes turcicus (Grouvelle)

[عبد الرحمن الجارحي]

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.
Similar species
Rusty grain beetle (Cryptolestes ferrugineus)
Flat grain beetle (Cryptolestes pusillus)
Foreign grain beetle (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
Control grain insect pests
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.