134 



laboratory pupated after about a month, the adults emerging in 

 about a fortnight. On the high plateaux of the island mangos and 

 oranges are not attacked. 



Jack (R. W.). Tobacco Pests of Rhodesia. Part h—RJwdesia Agric. 

 Jl., Salisbury, xvi, no. 6, December 1919, pp. 542-548, 5 plates. 



This account of the tobacco pests of Rhodesia is a revision of earlier 

 work [R.A.E., A, i, 287]. While no new pests of importance have 

 been observed, somie further information regarding the existing ones 

 has been obtained. The damage done by cutworms and the remecUes 

 for them are discussed [R.A.E., A, vi, 536]. Other moths dealt with 

 are Phfhoriinaea heliopa, Lwr. (stem borer), P. opercidella, Z. (tobacco 

 miner or splitworin), and Heliotkis {Chloridea) ohsolela (tobacco 

 budworm), which appears each year but is worse at some seasons 

 than others. The life-cycle of this moth has been worked out in 

 the United States but is not thoroughly known in South Africa. 

 It seems probable that four or five complete broods occur in the year. 

 The eggs are laid on the heart of the plant, or later on the seed-heads, 

 and hatch in 3 to 5 days. The caterpillars eat into the unfolding 

 leaves and later attack the seed-pods. Pupation occurs in the ground, 

 the adult emerging in from 17 to 27 days in the summer. Pupation 

 beginning in March may continue throughout the winter, the adults 

 emerging in October, but another generation frequently occurs in 

 April and May. The generations are therefore irregular. Ploughing, 

 harrowing and rolliu« the ground before October should destroy 

 many of the pupae and expose others. Hand-picking the caterpillars 

 during topping operations is also recommended. A poison mixture 

 used for bud-injury in the United States is recommended, but would 

 need to be used at greater strength. This consists of one table- 

 spoonful of Paris green to a quart of slaked lime, flour or maize meal, 

 and should be dusted on the buds, care being taken not to scorch 

 the plants. 



Minor pests of tobacco are LapJiygnui exigua, Hb. (pigweed cater- 

 pillar) and Prodenia litura, F. (tomato caterpillar), both of which 

 pass through several generations in a year. In cases of bad infestation 

 the plants should be sprayed with 1 lb. lead arsenate paste to 16 gals, 

 water, or 1 lb. powder to 30 gals. ; I lb. Paris green with I lb. fresh 

 lime to 40 gals, water is also recommended. 



Watson (J. R.). The Native Host-Plant of the Camphor Thrips 



{Cryptothrips floridensis). — Florida Buqgist, Gainesville, iii, no. 2, 

 September 1919, pp. 25-27. [Received 22nd January 1920.] 



The camphor thrips {Cryptothrips floridensis) has been found in 

 Florida to have an alternative food-plant in the native bays of the 

 genus Tamala, especially T. littoralis. It would therefore appear 

 to be indigenous, and this discovery has led to a re-examination of 

 the species recorded from Ceylon [R.A.E., A, ii, 597 ; iii, 357], and 

 it is believed that the latter is probably distinct though closely 

 related. The life-history in Florida has not been thoroughly 

 worked out. A single generation was reared in May 1913. The 

 eggs hatched in 8 or 9 days and the larvae had become adults by 

 the 24th day. 



