PESTS of STORED GRAINS Worldwide Losses in Stored Products Caused by Insects Have Been Estimated to Be Between 5 and 10%
PESTS OF STORED GRAINS Worldwide losses in stored products caused by insects have been estimated to be between 5 and 10%. Stored-product insects cause serious postharvest losses, estimated to be from 9% in developed countries to 20% or more in developing countries. They also contribute to contamination of food products by presence of live insects, insect products such as chemical excretions, dead insects and insect body fragments and accumulation of chemical insecticide residues in food, making the food unfit for human consumption. 1. Pulse Beetle, Callosobruchus chinensis L.: (Coleoptera: Bruchidae) Distribution: The beetle’s natural ranges are in the tropics and subtropics of Asia. Host Range: C. chinensis is a common and major pest of stored legumes. Preferred hosts are Vigna radiata (mung bean), Pisum sativum (pea), Vigna unguiculata (cowpea), Cajanus cajan (pigeon pea), Vigna angularis (adzuki bean) and Lens culinaris (lentil). Nature of Damage: The larvae chew tunnels through the bean until it is ready to pupate. Larvae feed and develop inside the seed and when adults emerge they leave a neat circular exit hole. Heavy infestation causes the commodity to heat. This results in loss of quality and mould growth. 2. Lesser Grain Borer, Rhyzopertha dominica Fabricius: (Coleoptera: Bostrichidae) Distribution and Status: It is found in India, Algeria, Greece, the USA, New South Wales (Australia), Japan and China. Host Range: It is found on wheat, rice, maize, sorghum, barley, lentils, army biscuits, ship biscuits, stored and dried potatoes, corn flour, beans, pumpkin seeds, tamarind seeds and millets. Nature of Damage: The lesser grain borer is characterized as both an internal and external feeder and is a serious pest of both whole kernel stored grain and cereal products.
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