359 



by one man. The powerful blower, which is placed on a stand for use, 

 proved capable of driving the gases to a considerable distance under- 

 ground, the ants being destroyed within a radius of about 130 yards. 

 The gases are produced by burning sulphur in a closed furnace, whence 

 they are lead to the ant-hole by a metal pipe. The high toxicity of 

 the gases in this case is held to be due to CSO of which 1 per thousand 

 was present on analysis, this proportion being sufficient to kill the 

 ants in about 4 minutes. A large-sized nest can be treated in 18 

 minutes with this apparatus. 



Akrow (G. J.). The Khapra Beetle (Trogoderma khapra, sp. n.), an 

 Indian Grain Pest. — Ann. Mag. Nat. Hist., London, xix, no. 114, 

 June 1917, pp. 481-482. 



Trogoderma Jchapra, sp. n., has previously been figured and recorded 

 under the name, Attagenus undulatus, Motch. [see this Review, v, 

 1917, p. 126]. It is found in enormous profusion in cargoes of wheat 

 from Karachi and Bombay, but has not occurred in grain imported 

 from countries other than India, nor has it been known to perpetuate 

 itself in Europe. 



Deakin (K. H.). Insect Pests of Agriculture in British East Africa. — 

 Ann. App. Biol, London, 1916, ii, no. 4, pp. 241-244. [Received 

 28th July 1917]. 



During 1914 large bands of the locust, Schistocerca peregrina, in 

 both the adult and larval stages, appeared throughout the Protec- 

 torate, causing, however, only minor injuries to coffee and maize 

 crops. Antestia variegata (African coffee bug) is the most serious pest 

 attacking coffee, but its numbers are periodically lessened by a 

 Chalcid which parasitises more than 50 per cent, of its eggs. Other 

 pests attacking coffee are the scale-insects, Coccus {Lecanium) africanus 

 and Saissetia {Lecanium) ni{)ra, the latter being heavily parasitised, 

 and the cutworm, Euxoa segetum, which can be controlled by clean 

 cultivation and the use of poisoned bait. The insects recorded on 

 citrus plants include : — Argyroploce leucotreta, the caterpillars of which 

 attack ripe oranges ; the Australian bug, Icen/a purchasi, which 

 however cannot be regarded as a pest ; small Halticid beetles which 

 suddenly appear in swarms and seriously injure the young leaves ; 

 Papilio mackinoni ; and a small mite, not yet identified. Eriosoma 

 lanigerum has been recorded on apples, but winged individuals have 

 not yet been observed. The leaves of quince trees have been seriously 

 damaged by the larvae of the moth, Orgyia vetusta, which is naturally 

 controlled by an Ichneumonid. The larvae of the moth, Duomitus 

 capensis, kill the branches of a native tree {Cassia didymobotrya) 

 by boring through them. The black wattle {Acacia decurrens) is 

 attacked by what is believed to be the larva of a Buprestid, but the 

 adult has not yet been reared. The best means of control is to fell 

 and strip the bark of! all trees that are attacked, and to remove all 

 that are in poor condition. This tree is also injured by Jassid and 

 Capsid bugs. 



