CO885-(19-20) — Page 353

PUBLIC RECORD OFFICE

Reference :-

C.O. 885

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ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH——NOT TO

Young plant:-

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SAMPLE RETURN OF CROP-PESTS.

Insect Pests of Cotton in India.

Chrotogonus trachypterus, Blanch., and probably other species attack the plants when quite young; specimens are sent.

Agrotis ypsilon, Hübn., and rarely other species of Agrotis and Euxoa attack the young plants. An account has been published in the memoirs of the Depart- ment (Entom. Series, Vol. I.).

Stem borers:--

Sphenoptera gossypii, Kerr., attacks the half-grown plants, the larva boring in the stem and killing the whole plant. Only the indigenous varieties are attacked and not the tree-cottons. The pest occurs commonly in Bombay and the Central Provinces, less so in the Punjab and United Provinces, very rarely in Bengal, and sometimes is common in Madras.

Pempheres affinis, Fst., is found abundantly in the stems of cotton of all kinds, particularly the tree-cottons, Egyptian and American cottons, and the cottons of any kinds that are long in the ground; the larvæ are found in the stems near the soil- level and cause swelling of the stem there. The attacked plants do not thrive and in any wind break off. The pest is a very serious one in tree-cottons or any cottons that are grown for more than six months; it is known in Bengal, the United Provinces, and Madras.

Alcides leopardus, Oliv., attacks principally tree-cottons, the larvæ boring in It has been the branches and twigs mainly and not doing much damage as a rule. a serious pest in some experimental cultivation of tree-cotton and probably occurs in all parts of India.

Bollworms :-

The American bollworm (Heliothis ormigera) is one of the common insects, but has never been found in cotton bolls in India and only once found feeding on the buds of the cotton plant; it cannot, therefore, be put down as a cotton pest.

Nor can the pink cotton seed caterpillar, Stagmatophora coriacella, Meyr., which feeds exclusively in the old bolls left on the plant and which never attacks the green boll nor the ordinary seed-cotton picked at maturity in the ordinary way; this is necessary to note, as the allied Egyptian species (Š. gossypiella, Wals.) has been referred to (? rightly) as a bollworm.

Earias insulana, Boisd., and E. fabia, Stoll., are the common bollworms, with Gelechia gossypiella, Saund., all occurring in the green boll, which they destroy more or less completely. Earias is also found in the shoots, and never in the seed; while Gelechia is common in the seed after plucking (where it often hibernates) and is only otherwise known to breed in some wild Malvaceæ, such as Thespesia populnea. Earias insulana was the species in the serious and widespread outbreaks, though all three species occur all over India and Burma.

Leaf-eating caterpillars:-

No species does serious harm, though both Laphygma exigua and Prodenia littoralis occur widely in India on other crops.

Tarache notabilis, Sow., has been the cause of small attacks on cotton in the Punjab and the Central Provinces; it occurs widely spread over India, not generally as a pest at all.

Cosmophila erosa, Wlk., is another caterpillar attacking mainly the young plants and not doing noticeable damage.

Leaf-rolling caterpillars :-

Sylepta derogata, Fabr. (multilinealis, Guen.), is a serious pest to American and Egyptian cottons, not usually a pest to the indigenous varieties which form the greater part of the cultivation; the caterpillars roll the leaves and feed upon them, A full account has been published in the every leaf being eaten in a bad attack. Memoirs of the Agricultural Department (Entom. Series, Vol. II.).

Phycita infusella, Meyr., rolls the young shoots of young plants and retards their growth; it is not a serious pest, though widespread over India. Leaf-sucking insects :—

Aphis gossypii, Glov., is a common pest to the indigenous cottons and does damage in some seasons over large areas; it attacks all varieties and in some years

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reduces the yield perceptibly by weakening the plants and by promoting the growth of " black blight "on the leaves.

Empoasca, n. sp., sucks the leaves of the young plants and weakens them. In the American and three Egyptian varieties it causes a curling of the leaves and stunted growth. It occurs throughout India. (Specimens are sent.) Boll-sucking Insects :-

Dysdercus cingulatus, Fabr., is the red cotton bug, the equivalent of the cotton stainers found on all cotton; it damages the seeds in the green boll and affects the quality of the lint, though not by staining it. It occurs throughout India commonly. A full account has been published in the memoirs of the Agricultural Department. (Entom., Ser. II.)

Oxycarenus laetus, Kby., sucks the seeds in the open or damaged bolls, laying its eggs in the lint and the young living there. It affects the seed, both in its oil-content and in its germinating power, and occurs abundantly in all varieties of cotton throughout India.

Many other insects live on the cotton plant, occasionally or habitually, but these are not included, as they are not known to affect the crop perceptibly. The pests of this crop have been studied carefully in the cotton-growing areas of India but not in Burma, where there are possibly other pests.

Apple:-

The only known pest of apple in India is the woolly aphis (Schizoneura lanigera, Hausm.). This is known to occur in Kumaon and in the Nilgiri Hills, and it has been very destructive and is now threatening the industry in the Himalayas. The apple will grow only in the hills at an elevation with a temperate climate and is only cultivated on a comparatively small scale. It has other pests, some probably indigenous and peculiar to India, but these have not as yet been studied.

THE FOLLOWING SCHEDULE OF FOOD PLANTS 18 SUGGESTED UNDER WHICH TO GROUP THE PESTS AND DISEASES. Cereals :-

Wheat and temperate cereals.

Rice.

Maize.

Sorghums.

Tropical millets. Sugar-cane.

Fodder grasses.

Pulses:-

Temperate pulses (including the Indian cold weather pulses). Pigeon pea.

Tropical pulses.

Lucerne and tropical fodder pulses.

Clover and temperate fodder pulses.

Oil-seeds :--

Cruciferous plants (including all cultivated species)

Ground-nut.

Castor.

Sesamum.

Sunflower.

Fibres :-

Cotton.

Jute.

Flax.

Sann-hemp.

Agave, sisal, &c.

Root crops :-

Beet. Potato. Sweet potato. Yams.

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