COLLECTING AND PRESERVING TNSECTS— BANKS. 



103 



few months previous. Here one will usually find in the bark of the 

 roots, stumps, main stems, tops, branches, and twigs different stages 

 of many species of barkbeetles and bark-inhabiting larva?, together 

 with their natural enemies and associates; and the wood will yield 

 many more. 



Lumbering regions and sawmill yards are especially prolific in 

 specimens at all times, as are also broken branches, individual trees, 

 and groups injured or killed by 

 insects, felled by storm, or 

 otherwise rendered attractive 

 to insects. During the spring, 

 summer, and fall the foliage will 

 yield specimens almost unlim- 

 ited in number and variety. 

 But one should remember, as 

 has already been indicated, 

 that it is not the number and 

 variety, but those of most im- 

 portance that are to be sought 

 out, noted, collected, and 

 studied. It is often better to 

 spend a day in the diligent 

 search for all that can be found 

 in or on a single tree, or in 

 observing and recording in the 

 notebook all that can be found 

 out about a single species, than 

 merely to collect hundreds of 

 specimens or many species 

 without careful records. 



Indeed, the proper recording 

 of what one sees at the time 

 the observations are made is of 

 the greatest importance, and is the one thing the student should 

 practice more, perhaps, than anything else. 



The collector should be constantly on the lookout for the natural 

 enemies of the principal injurious species. One class of the enemies 

 of insects consists of parasitic Hymenoptera, Diptera, etc., found in 

 the adult, larval, or pupal stage, associated with their host, the larvae 

 as external or internal feeders on the larva?, pupa?, or adults of 

 the injurious species, and the adult parasites ovipositing on or in 

 the victims, or in the bark or other infested parts of the plant. 

 The insect enemies of the other class are predatory species of 

 Coleoptera, Hemiptera, Hymenoptera, and other kinds of insects 

 which attack and kill their victims, and either devour them or suck 

 out the liquid parts of their bodies. There are also insect diseases 

 which maj 7 be indicated by a white powdery substance on the bodies 



Fig. 1(>2. — Galleries of aScolytid beetle. Pityi 

 genes cariniceps. 



