THE INSECT WORLD. 



67 



Termites become injurious in one of two ways : they either eat 

 into wood-work of furniture and buildings, or they attack grow- 

 ing plants. In the Northern and Eastern United States they 

 confine themselves to dead wood, and we have only a single spe- 

 cies, — Termes fiavipes ; but in the South and Southwest they 

 attack living plants, among them orange-trees and sugar-cane. 

 In buildings they sometimes live in beams, weakening them to 

 such an extent as to threaten or actually cause collapse. Not 

 many years ago some of the heavy wooden supports of the Bos- 

 ton State House were found infested, and more recently a build- 

 ing in Cleveland, Ohio, was invaded, requiring prompt measures 

 to prevent accident. They also attack stored products in gen- 

 eral, skilfully concealing their presence by leaving the outer sur- 

 face untouched. Thus, in a pile of old records stored in a vault of 

 the United States Department of Agriculture, a large proportion 

 was found badly injured, though no external trace appeared. In 

 the United States National Museum is a mass of black linen 

 thread from a South American store-house in which the outer 

 form of a pile of skeins is accurately preserved, while all below 

 is a mass of hard, black galleries. These are made of the partly 

 digested and excreted thread itself ; and so we find that in the 

 galleries in logs or trees the walls are composed of partly digested 

 wood-fibre. 



Termites are often found in decaying stumps, and sometimes 

 in the roots and stems of weak and dying plants ; in the latter 

 case often hastening or inducing death. In the Southern States 

 they are more abundant and troublesome, attacking sugar-cane 

 and also eating the bark of orange-trees at the crown. 



REMEDIAL MEASURES. 



Where the insects are found in buildings, injecting bisulphide 

 of carbon into their galleries will destroy them. They should be 

 traced to their outside nest, if possible, and, when found, this 

 should be destroyed. Frequently an old stump of some large 

 tree may be a centre from which a district becomes infested, and 

 the bisulphide should be liberally employed wherever the insects 

 are obser^^ed in numbers. 



On growing plants the bisulphide is also useful in many in- 

 stances ; but here, too, the effort should be made to discover the 



