400 



found, especially in the Tropics, that one species becomes dominant 

 in a certain region at the expense of all others. The Argentine ant 

 {Iridomyrmex humilis) has entirely supplanted Pheidole viegacephala 

 in Madeira, and is similarly displacing all other ants in the Southern 

 States of America, while Pheidole megacejyJiala in turn displaced other 

 sj^ecies such as Prenolepis longicornis and Solenopsis geminata var. 

 rufa in certain districts in Hawaii. In the humid valleys P. megacephala 

 is exceedingly abundant ; during heavy rains, however, the ants suffer 

 severe losses, and it is at this time that they attack unprotected 

 apiaries, swarming into the hives in such numbers as to destroy the 

 bees or drive them away. The best protection against their depreda- 

 tions is to support the corners of the hive on spikes coated with 

 axle-grease, to which the ants have a great aversion. Unfortunately 

 their attacks upon insects include beneficial as well as harmful species, 

 and parasitic flies which have been liberated and have appeared to 

 have established themselves during the rainy season will sometimes 

 entirely disappear during the dry season, when P. megacephala is 

 abundant. In Hawaii the species is not sufficiently numerous to 

 counteract the increase of the liberated flies. While ants are 

 frequently regarded as noxious owing to their relation to Aphids, 

 Coccids and leaf-hoppers, it must be remembered that they frequently 

 devour these insects, especially when there is a shortage of honey-dew. 

 They have also been recorded as destroying cochineal insects and 

 eating some of the mealy-bugs on sugar-cane. By removing the 

 sweet excretions produced by various bugs upon the leaves they check 

 the growi:!! of destructive leaf-fungi. As a household pest this species 

 is of no great importance, as food can easily be protected from them. 

 A case is recorded of some fish infested with Dermestid larvae, in 

 which ants cleared out all the larvae within two days, leaving the 

 fish untouched. In their activities against household flies they render 

 valuable service ; while in the field they attack many of the most 

 destructive pests, including the powerful Hawaiian mole-cricket {GnjUo- 

 talpa africana). In Cuba another mole-cricket [Scapteriscus didactylus] 

 is said to have become quite scarce owing to its destruction by ants. 

 In Fiji, almost every insect collected at lights by the author had a 

 number of ants attached to it. The June beetles {Rhopaea sp.), which 

 destroy large areas of sugar-cane by feeding upon the roots, are 

 vigorously attacked by the ants, many of which cling to a single 

 specimen. As a control for ants in houses, a lamp-wick dipped in 

 bichloride of mercury, then dried and pinned round the legs of furniture, 

 is recommended ; or sodium fluoride dusted in places frequented by 

 ants causes them to disappear. 



An annotated bibliography of 22 works is given. 



Sen (P. C). Alcides frenatus, a Coleopteron Injurious to the Mango 

 Tree in Bengal. — Mthly. Bull. Agric. Intell. & PI. Dis., Rome, viii, 

 no. 2, February 1917, pp. 315-316. (Abstract from Agric. DepL, 

 Bengal, Leaflet no. 2 of 1916.) 



Alcides frenatus, Fst. (mango-shoot weevil) causes severe injury to 

 mango-trees, the larvae boring galleries in the new shoots. Any 

 shoots containing eggs or larvae should be destroyed. 



