and ground-nuts, appeared later on cotton, damaging the leaves and 

 bolls. The weevil, Apion armipes, Wagn,, was less abundant than in 

 previous years. The larva rings the bush about one inch above the 

 ground, causing the leaves above to turn red. Termites invariably 

 complete the destruction of the plant ; attacked plants should be cut 

 out and burned. 



Of the Lepidoptera, Diparopsis castanea, Hmp., (red boll-worm), 

 is at present the most serious pest of cotton in Nyasaland. 

 The duration of the stages in the life-history observed in 1914-15 

 were: — Egg-stage, 2-5 days; larval, 23-38 days; pupal, 13-49 

 days. The eggs are laid singly on young shoots. The larvae feed 

 for some days on the outside of the boll or on the bracts, then 

 enter the boll and complete the larval stage. Pupation takes place 

 in the soil. Wild Malvaceae are probably the native food-plants. 

 A predaceous wasp and a bacterial disease have been recorded, but no 

 Hymenopterous parasite of this species was found. A single Tachinid 

 fly was reared from several hundred larvae. Hand-picking early in 

 the season and frequent hoeing are recommended. Chloridea obsoleta, F., 

 appears to be increasing in importance in the Protectorate. Its 

 omnivorous habits, great fecundity and apparent freedom from 

 parasites are all favourable to its increase. The egg-stage occupies 

 from 6 to 10 days, the larval, from 18 to 35, the pupal, from 15 to 25 

 days. The second brood, occurring at the end of February and in 

 March, is the most destructive. The marked preference shown for 

 the chick pea indicates that a trial of this plant as a trap-crop is 

 advisable. Prodenia litura, F., was abundant in February and March. 

 Earias insulana, Boisd., is generally distributed. The following 

 extremes in the life-cycle were observed : —Egg-stage, 4-8 days ; 

 larval, 16-28 days ; pupal, 14-19 days. The most serious damage 

 occurred in December and January, when the cotton was about 8 inches 

 high. Infestation was most severe in low-lying districts, possibly owing 

 to the absence of natural controls. The food-plants noted were 

 Hibiscus, mulberry, and Eriodendron. The only parasite observed was 

 a Braconid, perhaps a species of Rhogas. Sylepta derogata, F., was 

 abundant at the south-west end of Lake Nyasa, especially during 

 March. The durations of the stages of this leaf-roller are :— ' 

 Egg-stage, 3-6 days ; larval, 17-29 days ; pupal, 6-18 days. Two 

 Chalcid parasites have been reared from it. In the Shire Highlands 

 two small Braconids occurred in about 1 per cent, of the larvae and a 

 predaceous Eumenid wasp is known to attack them. Tortrix sp. 

 (cotton shoot Webber) occurred in January and the second brood in 

 March. The leading shoot was usually attacked, the larvae feeding 

 on the young leaves, unopened flowers and bolls, frequently gnawing 

 the stem and so causing the shoot to curl. The lar^^'al stage is about 

 28 days, the pupal, 8-11 days. For Tortrix and Sylepta, hand-picking 

 is recommended. Acrocercops bifasciata, Wlsm. (cotton leaf-miner) 

 was abundant on a plot of late-planted cotton. This insect was also 

 reported on the low-lying river plantations and may be a pest of some 

 importance. The eggs are laid on the under surface of the leaf. The 

 larvae penetrate the tissues, where they remain until mature. Pupation 

 takes place on the outside of the leaf or stem, occasionally on the surface 

 of the soil at the base of the host plant. The larval stage lasts from 

 25 to 32 days, the pupal, from 5 to 7 days. No parasites or predaceous 



