Stored Product Pests and Their Control Dr. Richard M. Houseman Department of Entomology University of Missouri

Stored Product Pests Two main orders Order Coleoptera Beetles 300,000 species world-wide 40,000 species in U.S. Order Lepidoptera Butterflies 112,000 species world-wide 11,000 species in U.S. Damage is done mostly by the immature stages.

Missouri Stored Product Pests 12 Important Pests 10 beetles 2 moths Can be divided into two main feeding groups Pests of whole grains Consume the grain embryos (protein) Pests of processed grains

Whole Grains Rice weevil (Sitophilus oryzae) Granary weevil (Sitophilus granarius) More common in granaries and mills Pierce grains with beak and lay eggs inside Many cereal grains and seeds infested Several are found in storerooms, pantries, garages

Whole Grains Lesser grain borer (Rhyzopertha dominica) Infests grains in storage or in transport Strong jaws to open grain and then lay eggs Rarely a problem in homes or stores Unless materials arrive infested

Whole Grains Cowpea weevil Not true weevils Only infest legumes (Callosobruchus maculatus) Not true weevils No snout Only infest legumes Peas, cowpeas, beans Lay eggs on outside of seeds and the larvae penetrate

Whole Grains Angoumois grain moth Mostly a problem in grain storage (Sitotroga cerealella) Mostly a problem in grain storage Less common in homes Commonly found in whole kernel corn Will fly inside buildings Dr. RM Houseman

Processed Grains Sawtoothed grain beetle (Oryzaephilus surinamensis) Six teeth along edges of pronotum Eggs deposited into foodstuffs Larvae look like lumps and stay in foodstuff Adults will wander around

Processed Grains Warehouse beetle Infest grain-based products (Trogoderma spp.) Infest grain-based products Cereal Spices Rodent baits Dog food Found in warehouses, storage rooms, homes

Processed Grains Cigarette beetle (Lasioderma serricorne) Covered with tiny hairs that give it a sheen Very small larvae Difficult to locate Covered with product Infest many things Spices, pet food, prescription drugs, tobacco, cosmetics,

Processed Grains Drugstore beetle Similar to cigarette beetle (Stegobium paniceum) Similar to cigarette beetle Dull, dark appearance Infest many things Spices, pet food, prescription drugs, tobacco, cosmetics,

Processed Grains Confused flour beetle Red flour beetle (Tribolium confusum) Red flour beetle (Tribolium castaneum) Dry milled, cereal products Flour mills, retail stores, homes Nearly impossible to avoid this pest in mills Flour, cornmeal, cake mixes may harbor them

Processed Grains Indianmeal moth Most common pantry pest in Missouri (Plodia interpunctella) Most common pantry pest in Missouri Storage areas, stores, homes Life cycle of 2 months Larvae spin silk Can cover the product Will leave product and wander for distances May even hang from ceilings

Stored Product Pest Control Four basic steps Locate infested product Discard infested products Cheaper to replace it than to freeze/heat/treat Clean infested area thoroughly Prevent new infestations Thick plastic, metal, air-tight containers