Harmful insects

Harmful insects

1. Insect Pests of Stored Products

2. Primary storage pests: Insects that infest undamaged grains Common name Pest Host Rice weevil Sitophilus oryzae, S. zeamais, S. granarius Rice, wheat, sorghum, barley, maize Khapra beetle, Trogoderma granarium Cereals, groundnut and pulses Lesser grain borer Rhyzopertha dominica Paddy, maize and wheat Angoumois grain moth Sitotroga cerealella Rice, wheat and maize Pulse beetle Tamarind/Groundnut Bruchid Callosobruchus chinensis, C. maculatus Caryedon serratus Pulses, bean and gram Ground nut, tamarind and other legumes Wheat flour, cereal bran, peanuts, Cigarette beetle Lasioderma sericorne cocoa beans, spices, turmeric, chillies, ginger, stored tobacco, cigarette

3. Secondary storage pest: Insects that damage broken or already damaged grains Common name Pest Host Red flour beetle Tribolium castaneum, Tribolium confusum Broken grains, damaged grains, milled products, machinery Long headed flour beetle Latheticus oryzae Saw toothed grain beetle Cryptolestus minutas, Laemophloeus pusillus Dry fruits , maize, cereals and oil seeds Rice moth Corcyra cephalonica Cereals, oilseeds nuts, dry fruits, rice and pulse Fig moth or almond moth Ephestia cautella Maize, cereals, dry fruits, Indian meal moth Plodia interpunctella groundnut, and cereals products

4. Rice Weevils ( Sitophilus oryzae ) • The adult weevil can be readily identified by its long slender snout • Adults are less than 3/16 of an inch in length, and color varies from medium brown to black • The thorax is pitted with elongate depressions, and there are no wings under the wing covers, so the species is flightless • The granary weevil female chews a small hole in a kernel, into which she deposits an egg • Each female can deposit between fifty and two hundred and fifty eggs

5. Khapra Beetle ( Trogoderma granarium ) • The adults are oblong-oval beetles, approximately 1.6 to 3.0 mm long by 0.9 to 1.7 mm wide • Males are brown to black with indistinct reddish brown markings on elytra. Females are slightly larger than males and lighter in color • The head is small and deflexed with a short 11- segmented antennae • The antennae have a club of three to five segments • The adults are covered with hairs • Adult khapra beetles have wings, but apparently do not fly and feed very little • This beetle has never been observed to fly; therefore, its spread is probably dependent on movement of infested goods or in containers where it may be transported while in diapause

6. Saw-Toothed Grain Beetle ( Oryzaephilus surinamensis ) • Saw-toothed grain beetle is a slender, flat, brown beetle about 1/10 of an inch long • It gains its name from the peculiar structure of the thorax, which bears six sawtooth-like projections on each side • The female beetle lays 43 to 285 eggs • Eggs are deposited on cracks in the kernels and adults and larvae feed on damaged kernels, fines, and occasionally the germ of the intact grain • This species is a good flier, but is most commonly associated with areas of high temperature and humidity

7. Lesser Grain Borer ( Rhizopertha dominica ) • The adults of this species are readily distinguished by the squared-off appearance at the front of the body • The adults are less than 1/8 of an inch in length and range from reddish brown to dark brown • This species is a good flier, and adults are readily trapped in pheromone-baited traps at harvest • The lesser grain borer is a long-lived species and a female can lay up to 500 eggs • Heavy infestation with lesser grain borers can be identified by a sweetish, musty odor in the storage. This odor is a result of the male-produced aggregation pheromone that has been demonstrated to be an effective lure for use in tra