STORED GRAIN PEST Corcyra cephalonica (THE RICE MOTH)

SYSTEMATIC POSITION PHYLUM : ARTHROPODA (jointed appendages) CLASS : INSECTA (tagmata, 3pairs of legs) SUB CLASS : PTERYGOTA (wings present) DIVISION : ENDOPTERYGOTA (wings develop internally, holometabolous) ORDER : LEPIDOPTERA (moths) FAMILY : PYRALIDAE GENUS : Corcyra SPECIES : cephalonica

DISTRIBUTION OF RICE MOTH

General features A COSMOPOLITAN, major stored grain pest. A native of the tropics, enjoys a warm climate but in temperate areas survives in heated stores. Mainly attacks rice grains. Wheat, millets, groundnut, sorghum, corn, maize and other cereals are the SECONDARY HOSTS. Occurs in most of the countries including India, Africa, Australia, Italy, Germany, France etc.

ADULT RICE MOTH Pale brown coloured, 12mm long with a wing span of about 15mm. No distinct markings, veins are darkened. Head bears a projected tuft of scales. Nocturnal, Short lived - 2 to 4 days. The hind wings are translucent.

STRUCTURE OF ADULT GENERAL IDEA

LIFE HISTORY OF Corcyra cephalonica Holometabolous Includes four stages- EGG LARVA PUPA ADULT The larva is known as CATERPILLAR. Breeding occurs in March to November

EGG LAYING The Eggs are laid on grains, on containers or any surface near grains either singly or in clusters. Whitish, oval in shape, 0.5mm long and having an incubation period of 4-5 days. Fecundity i.e. the total eggs laid by female in lifetime is 150-200 eggs.

THE CATERPILLAR (LARVA) It is creamy white, with a prominent head. It moves about actively and feeds on broken grains. Become full grown in 21 to 41 days after 5 moults. The full grown larva is pale whitish, 15 mm long with short scattered hairs and no markings on body.

GENERAL STRUCTURE

Larva undergoes 5 moults and form 6 instars by feeding and growing. Cutting and chewing type of mouth parts. Feeds on broken grains and spins a web to join grains. Hibernates in winter and pupates in spring.

PUPA Larvae prepare silken cocoons among the grains for pupation. Pupation takes place inside a tough, opaque, whitish cocoon. Non feeding, immotile, dormant stage involving developmental characters of adults. Lasts for 10 days, may extend upto40-50 days to tide over winters.

DEVELOPMENT OF PUPA FROM LARVA

The pupa finally changes into adult moth in about 10 days. Mating and egg laying occurs immediately after emergence of adults. The entire life cycle takes about 33 to 52 days. 6 generations passed in an year. Larvae mainly cause the damage as these are the voracious feeders, active, and mobile stages.

AN OVERALL GLIMPSE AT THE LIFE CYCLE 4-5 DAYS EGG LARVA 21-41 DAYS Taking place in stored grains. Adults start laying eggs after 1-2 days of emergence. Life cycle completes in 33 to 52 days. PUPA ADULT 10- 14 DAYS (2-4 DAYS)

DAMAGE CATERPILLARS cause the damage by webbing together grains and forming lump and feed from inside it. Reduction in MARKETING QUALITY of grains. Heavy infestation causes the entire stock change into a webbed mass with foul order. Grains unfit for human consumption. Oil seeds, dry fruits, other cereals are also attacked and infested causing severe damage.

WEBBING TOGETHER OF GRAINS

INFESTATION INFESTATION

CONTROL Control measures include physical, chemical and biological measures. PHYSICAL CONTROL: Manipulation of the storage environment, making it less favourable for the insects. Exposure of seeds to sun for 3 days in summer kill the pests. Stores should be clean and well ventilated. One godown should be used to store only one kind of grain.

5. Cracks, holes and crevices in the walls ,floors and ceilings of the store house should be prevented for not letting the pests in. CHEMICAL CONTROL: Contact poisons and fumigants are used to kill the pests. Pyrethrins of plant origins are mostly used due to low mammalian toxicity, unstable to sunlight, rapid breakdown. Fenvalerate and Deltamethrin are synthetic pyrethroids, highly toxic to the larvae.

BIOLOGICAL CONTROL: This is a safe method to get rid of insect pests of stored grain. Some of the biological species which are predators of the infecting pest are listed: NATURAL ENEMY TYPE LIFE STAGES 1. Acaropsellina docta Predator Eggs/ Larvae 2. Amphibolous venator Larvae 3. Antrocephalus mitys Parasite Larvae/ Pupae 4. Blattisocious keegani 5. Artema atlanta

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