360 



wash ; 3 lb. of lead arsenate to 50 gals, of water is best, but most 

 expensive ; J lb. arsenite of soda, 2 lb. quick or fresh water-slaked 

 lime, to 50 gals, water has proved effective. The Paris green spray, 

 consisting of 1 lb. Paris green, 2 lb. fresh hme and 160 gals, water, 

 yields a heavy precipitate and settles quickly. When ^ lucerne is 

 attacked, green stuff dipped in poisoned sugar solution strewn between 

 the rows has been found effective. 



The maize caterpillar, Cirphis loreyi, is related to the " army 

 worm," Cirphis unipunda, of America and India and occurs as a pest 

 of maize in Khodesia. The eggs are laid in strings within the leaf 

 sheaths of maize or grasses. The caterpillar feeds, probably at night, 

 on the young leaves of the heart. By day most of the larvae 

 seem to conceal themselves in the earth at the foot of the plant. 

 Pupation takes place in the soil ; the life-cycle is short-, and a 

 number of broods occur during the year. The natural food-plants 

 are wild grasses, especially Eleusine indica and Setaria verficiUata, both 

 of which occur on rich soil suitable for maize culture. Serious injury 

 has resulted upon the cultivation of such land. The develop- 

 ment is slow during the winter, larvae collected in Jime having 

 produced adults in August, the intervening period being passed in 

 the pupal stage. The facts mentioned concerning the origin of serious 

 attacks indicate that weeds must be kept down in the maize fields 

 from the beginning of cultivation. If the grass has been allowed to 

 grow, an inspection should be made for caterpillars in the earth at 

 bases of the plants. If many are present, it is better to wait for about 

 10 days until some have pupated before cultivating. The damage 

 would not be serious enough to call for remedial measures ; if the 

 " army worm " habit is developed, remedies similar to those used 

 for the "swarming caterpillar" are apphcable. 



Prodenia lilura, the tomato caterpillar, has been recorded as a pest 

 in Africa and India. The eggs are laid in clusters on the leaves, being 

 covered mth buff-coloured hairs from the body of the female moth. 

 The larvae hatch in 3-4 days, pupate 20 days later in the soil and the 

 adult emerges after about six days. The caterpillar is a general feeder, 

 having been recorded on tomato, potato, pea, tobacco, maize, castor oil 

 plant, etc. The larva, when hiding beneath the food-plant during the 

 day, may be collected by hand and destroyed. Plants badly infested 

 may be sprayed with one of the arsenicals used for pigweed caterpillar 

 or dusted when the leaves are wet with a mixture of 1 lb. Paris green 

 and 20 lb. of hme. 



The only important pest of tobacco is Chloridea obsolefa, the tobacco 

 budworm ; the same insect also attacks tomato fruit and, in America, 

 cotton bolls. The eggs, which are attached singly to the food-plants, 

 hatch in 3-5 days. The larvae reach maturity in 2-3 weeks and enter 

 the soil to pupate, the adult emerging two weeks later. This moth 

 remains in the pupal stage in the winter. The range of food-plants, 

 as indicated above, is considerable and this species has also been found 

 on linseed, cowpeas and ground-nuts. As a pest of tobacco, it has not 

 been found in Rhodesia feeding on the unopened buds, but the young 

 leaves in the centre of the plant have been attacked. The most 

 injurious brood is that which hatches out in February ; later broods 

 attack the seed-capsules, causing only minor damage. As the pupa 

 passes the winter near the surface of the soil, the most practical measure 



