15 



used against it consists of : — 1 oz. white arsenic, 2 oz. sal soda or 1 oz. 

 sodium hydroxide, mixed with 8 oz. water to which is added 16 lb. 

 sugar and enough water to make up the whole to three U.S. gallons of 

 sjrrup. In spite of what has been done, the ants continue to increase 

 and householders are moving to uninfested localities. This failure in 

 control is due to lack of organisation, but if undertaken by the muni- 

 cipality instead of being left to the individual, it should be successful. 



Bridwell (J. G.). Breeding Fruit-fly Parasites in the Hawaiian 

 Islands. — Jl. Econ. Entom., Concord, ix, no. 5, October 1916 

 pp. 472-476. 



This article details the methods employed in breeding the Opiine 

 Braconids introduced into Hawaii from West Africa and Australia 

 against Ceratitis cajjitata [see this Review, Ser. A, iii, 412, and iv, p. 289]. 



In the case of Opius humilis it was found that the damp atmosphere 

 caused by the fruit being enclosed on damp sand in a jar resulted in 

 dew on the glass and formed an obviously unfavourable environment 

 for the delicate parasites. A dry layer of sand placed in the bottom of 

 the box and a basket formed of wire netting in which the fruit was 

 kept separate, was found to be a much more satisfactory arrangement. 

 Under favourable conditions it is concluded that this parasite might 

 well eliminate the fruit fly from the thin-meated fruits such as coffee, 

 terminalia and elengi, but in the case of fleshy fruits, such as mango, 

 guava, peach and Chinese orange, the mechanical difficulty of parasi- 

 tising the maggots would prevent the parasite from being an important 

 factor. The author is convinced that under Hawaiian conditions, 

 C. capitata must be controlled by the use of parasites to reduce the 

 flies to the point where jjoisoned baits wdll be effective. 



Smith (H. S.). An Attempt to redefine the Host Relationships exhibited 

 by Entomophagous Insects. — JL Econ. Entom., Concord, ix, no. 5. 

 October 1916, pp. 477-486. 



Entomophagous insects are usually divided into two classes, parasitic 

 and predaceous, according to their method of feeding, though 

 there is no definite division between them. For example, the female 

 Scutellista cyanea deposits its eggs beneath the adult black scale 

 [Saissetia ohae] and the resulting larva feeds upon the eggs of the 

 host, of which it requires a large number, frequently several hundreds, 

 to complete its development, although it always matures beneath 

 a single scale. The usually accepted definition of a parasite 

 might therefore be enlarged by describing it as an entomophagous 

 insect which requires but a single individual host, or the eggs of a 

 single individual, to complete its development. Other insects on 

 the border line between parasites and predators are : — Macrorileyia 

 oecanthi, Ashm., a Chalcidoid found living in the pith of twigs in which 

 tree-crickets have laid their eggs, upon which it feeds, and Aphelinus 

 mytilaspidis, which is both parasitic and predaceous, feeding either 

 upon the adult or its progeny. 



