940 PROCEEDINGS OF THE THIED EXTOMOLOGIC-U. MEETING 



Wood-borers will be found both in dying, dead, and decaying trees, 

 as noted above, and also in living trees, where their presence is often 

 indicated by the extrusion of their sawdust-like excrement or by the 

 dying back of the bored branch or stems. The adults are compara- 

 tively rarely met with but may sometimes be found resting on the 

 attacked trees, although best obtained by collection and breeding of 

 the immature stages. In special cases, attacked stems may be enclosed 

 in wire gauze in order to trap the adults on their emergence. 



Root-borers, such as HepiaHds, are usually captured by accident and 

 are also best obtained by breeding. 



Streams and fonds furnish many insects which live in the water 

 either as larvse or adults. For purely aquatic insects a water-net will 

 be required but many of these fly by night and may be caught at Ught. 

 There are also many groups of insects, whose larval existence is aquatic 

 and the imaginal life aerial, and these may be caught along the edges 

 of streams and ponds, although some range far afield from water, which 

 they only approach to oviposit. It is only possible to search com- 

 paratively shallow areas with a water-net and a drag-hook may be 

 used to bring up weeds, sunken branches, etc., from greater depths. 

 These, if searched, will be found to yield a rich harvest, especially of 

 immature stages ; Ranatrid bugs, for example, will be found amongst 

 weeds, whilst fresh-water sponges contain the larvse of Sisijra. 



Different kinds of streams often have quite different ty|)es of insect- 

 fauna ; thus, some Species of dragon-flies afEect rapid, rocky-bedded 

 streams, whilst others prefer more sluggish streams with muddy bottoms 

 and banks. Similarly, some insects prefer small accumulations of 

 water whilst others live only in large ponds, lakes, or rivers. 



Holes in trees, which accumulate dead leaves or hold water after 

 rain, are favourite hiding and breeding places for some insects 

 and will often repay examination. Many beetles and mosquitos and 

 the Tabanid fly, Gaslroxides ater, habitually live and breed in such 

 situations. 



Hot Springs in other parts of the World have been recorded as con- 

 tainmg many insects which live habitually in water at a temperature 

 usually fatal to insect-life. I am not aware that any insects have been 

 noted in hot springs in India but it is probable that such may occur. 

 Similarly, in the United States the larva of an Ephydrid fly {Psilopa 

 Coq.)* has been found living, feeding, and swimming about in 

 Is of crude petroleum which are so numerous in the various oil- 



* " The Petroleum Fly in California," by D. L. Crawford, Pomona Cull. Journ. Ent. 

 IV, 687 697, figs. (May 1912). 



