Insect Pests of storage Dr Baoua Ibrahim INRAN-NIGER PICS COORDINATOR Kaboul, AAEP project training May 26-27
Hands-on Exercice • Four group • Each group will have one bag • Open the bag • Each members of the group take a sample of the product using Petri dishes • Collecte the following data – Number of living insect per species – Take a sample of 100 grains: • Record number of grain with insect eggs • Record number of grain with hole – Take a sample of 10 wet grain, open and record any insect larvae or adult
Insect Pests of Stored Products
Primary storage pests: Insects that infest undamaged grains Common name Pest Host Sitophilus oryzae, S. Rice weevil Rice, wheat, sorghum, barley, maize zeamais, S. granarius 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 Callosobruchus Pulse beetle chinensis, C. maculatus Pulses, bean and gram Tamarind/Groundnut Ground nut, tamarind and other Caryedon serratus Bruchid legumes Wheat flour, cereal bran, peanuts, Cigarette beetle Lasioderma sericorne cocoa beans, spices, turmeric, chillies, ginger, stored tobacco, cigarette
Secondary storage pest: Insects that damage broken or already damaged grains Common name Pest Host Broken grains, damaged Tribolium castaneum, Red flour beetle grains, milled products, machinery Tribolium confusum Long headed flour beetle Latheticus oryzae Cryptolestus minutas, Dry fruits , maize, cereals Saw toothed grain beetle Laemophloeus pusillus and oil seeds Cereals, oilseeds nuts, dry Rice moth Corcyra cephalonica fruits, rice and pulse Fig moth or almond moth Ephestia cautella Maize, cereals, dry fruits, Indian meal moth Plodia interpunctella groundnut, and cereals products
Cowpea weevil Callosobruchus chinensis (Linneaus) The cowpea weevil attacks field beans and peas. It then becomes a storage pest in granaries where it breeds continuously on dried pulses. It attacks chickpeas ( Cicer sp.), lentils ( Lens sp.), garden peas ( Pisum sp.) and mung beans ( Vigna sp.). The damage is distinctive. Larvae feed and develop inside the seed and when adults emerge they leave a neat circular exit hole. Each adult consumes approximately 25% of the seed from which it develops. Heavy infestation causes the commodity to heat. This results in loss of quality and mould growth.
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
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 traps
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
Flour Beetle ( Tribolium castaneum ) • These elongate, shiny beetles have short, clubbed antennae • Flour beetle is seldom found in grain and is more often associated with milled products • The insects reproduce faster when some fine material is present in the stored grain especially if grain moisture is more than 12% • Under optimal conditions females can lay up to 450 eggs over a lifespan that may be as long as eighteen months • The adults are good fliers • A pungent, bad odour in the grain is a sign of a large infestation of flour beetles
Angoumois Moth ( Sitotroga cerealella ) • Angoumois grain moth adults are brownish gray, slightly less than 1/2 inch long, with a long fringe of hairs on the wings • The forewings are clay-yellow and without markings; the hindwings are gray • Angoumois grain moths can be found infesting a variety of grain and food materials. They attack all cereal grains, however are most often found in corn and wheat • It is the only storage pest that will attack standing grains in the field
Rice Moth Corcyra cephalonica (Stainton, 1866) • A pest of stored rice, millets and other cereals. Prefers broken grains and flour. • Caterpillars cause the damage by webbing together grains and forming lump and feed from inside it. Larvae before pupation wander about and leave a lot of webbing in the grains, causing excessive lumping, which reduces marketing quality of the grains. • Adults light greyish-brown in colour, 12 mm long and with a wing span of about 15 mm, without any markings on the wings but veins are slightly darkened. Head bears a projected tuft of scales. Moths are short lived but realise a fecundity of 150 — 200 eggs per female within a few days after emergence. Larval period is 25-35 days in summer and may be extended in winter.
Indian Meal Moth ( Plodia interpunctella ) • Adult moths are about 3/8-inch (8 to 10mm) long when at rest and have a wing spread of about 1/2 to 3/4 inch (18 to 20mm) • The overall body color is generally dirty gray but the tip half of the wing is rusty brown or nearly bronze • This wing marking pattern allows Indian meal moth to be easily distinguished from other household moths • Indian meal moths develop in many kinds of stored foods. Coarsely ground grains and cereal products are commonly infested
Drugstore Beetle ( Stegobium paniceum ) • The adults are about 1/10 of an inch in length, cylindrical and uniform brown with fine silky hairs • The adult drugstore beetle has a three-segmented, sawlike antennae that is pressed to the body when at rest • This beetle lays eggs in almost any dry organic substance • The entire life cycle may be passed in less than two months
Tobacco Beetle( Lasioderma serricorne ) • The tobacco beetle is a small stout, oval, reddish-yellow or brownish-red beetle, with the head bent down nearly at a right angle to the body • It varies in size, but is usually about 1/10 of an inch long • The antennae of the tobacco beetle are saw-like and the head is somewhat retracted • The adult tobacco beetle lives 2 to 4 weeks, during which time each female may lay as many as 100 eggs
Rusty Grain Beetle ( Cryptolestes spp.) • These small insects (2 mm) are readily identified by their very long antennae • The antennae of both male and female rusty grain beetles are about half the length of the body • The rusty grain beetles have been recorded from wheat, flour, oilseeds, cassava root, dried fruits, and chilies • The adults are good fliers • Females can lay up to 400 eggs over a lifespan of up to nine months
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
Large Grain Borer (Prostephanus truncatus) Prostephanus truncatus is commonly referred to as "larger grain borer" with reference to its close cousin Rhyzopertha dominica which is relatively smaller in length hence referred to as "lesser grain borer". Prostephanus truncatus is approximately 35 millimetres (1.4 in) long as compared to 26 mm (1.0 in) long in Rhyzopertha dominica . At optimum conditions of 80% relative humidity and 32 °C (90 °F), and available food, Prostephanus truncatus completes its life cycle within 27 days. It is a serious pest of dried grains especially maize and dried cassava in West Africa.
Control
Control
Number of insects Wheat Mungbean PICS Control PICS Control 1 - 1 0 - 2 0 - - 15 3 - 0 - 1 4 0 - - 10 5 - 3 0 - 6 0 - - 27 7 - 1 0 - 8 0 - - 33
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