| Description | Fast moving dark brown-black beetle (3 mm long) with characteristic sawtooth-like projections on each side of the thorax. They arely fly, but adults climb well even on non-porous, vertical surfaces (e.g. glass). The white, flattened larvae feed and develop externally but are difficult to see. |
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| Distribution | Cosmopolitan. |
| Pest status | Major, widespread, regular. Primarily external feeding pest of milled products. It feeds on grain only after the seed coat has been broken (mechanically or by other insects). |
| Host range | Infests cereal grains, grain products, oilseeds, processed products of vegetable origin, peanuts and dried fruits. |
| Damage | A secondary pest which prefers damaged or processed kernels with a preference for germ. Larvae also attack germ in the whole cereal grains, changing the nutritional content and reducing the germination rate. |
| Life cycle | Adults live on average for 6–10 months, but some may live as long as 3 years. Each female beetle lays up to 300 eggs during its lifetime, laying them loosely throughout the foodstuff or inserting them into the crevice of a grain kernel. Eggs hatch in 3–5 days and the larvae feed and develop externally. Mature larvae create cocoon-like coverings by joining together small grains or fagments of foodstuffs with a sticky secretion in which they pupate. The development from egg to adult takes up to 4 weeks under optimal conditions of 33ºC and 80% relative humidity. Length of the life cycle is 17 weeks at 20°C, reproduction stops below 17.5°C. |
| Risk period | All year. |
| Means of protection |
Cultural control – The insect does not occur in standing crops. Therefore, good hygiene with storage and handling equipment should minimise infection. Prevention treatment by Methograin Delta IGR Grain Protectant is the primarily recommended product for prevention. To gain the widest possible range of protection Methograin Delta IGR Grain Protectant together with Methograin Fenitrothion 1000 can be applied. Chemical control – In case of infestation, fumigation in sealed storage. |
