A number of insect pests of a more or less serious nature attack the plant at different periods of growth. The American boll-worm (_Chloridea obsoleta_) does some damage annually in the Central Province (Ugboha, Agbede and Ishan); _Earias insulana_, F., the Egyptian boll-worm; _E. imbricata_, an allied species, and _Diparopsis castanea_ Hamp., the Sudan boll-worm, are common at Ibadan. The immature boll is often punctured by a scarlet and brown bug, identified as _Dysdercus superstitiosus_, Fabr., which enters the opened bolls also, and exudes a yellowish liquid, which stains the lint. The opened boll is also infested with three species of cotton-seed bugs—_Oxycarenus hyalinipennis_, _O. gossipinus_, and _O. Dudgeoni_—which do a large amount of damage in sapping the juices from the seed and rendering it unproductive. The most satisfactory method of dispersing this insect is to place the seed-cotton in a hot sun for several hours. Both _Oxycarenus_ and _Dysdercus_ may be trapped by placing piles of seed in the field at intervals, and treating them with kerosene when the insects have collected on them. A small caterpillar belonging to the family _Gelechiadæ_[4] is often found in the boll feeding on the seed, and a leaf-blistering blight, probably _Chlorita flavescens_, appears to be common in several places. A malady, chiefly on stems of exotic cottons, and known as “black-arm” in Georgia, U.S.A., is seen occasionally. The affection is not attributed to any animal or vegetable parasite. The ginneries erected by the British Cotton Growing Association are probably some of the best equipped in the world. The Marlborough Ginnery at Ibadan (Fig. 23) has at present the largest output, although the Jones Ginnery at Oshogbo is larger, and is expected to receive a greater quantity of cotton for treatment in the future. The third, which is working in the Western Province, is the Churchill Ginnery at Lafenwa, near Abeokuta. Smaller ginneries have been erected at Eruwa Road, Iwo, Oyo, and Agege in the Western Province, but are at present unused. In the Central Province the Illushi Ginnery on the Niger is capable of treating all the cotton of the adjoining districts. A photograph of cotton bales at Ibadan is reproduced (Fig. 23).