2 FOREST ENTOMOLOGY. 



tries by observation and comparison to classify his captures according 

 to the difference in colour, size, and other variations. He also strives 

 to enrich the local fauna by fresh captures. On the other hand, the 

 economic entomologist seizes these data of the collector or systematic 

 biologist, goes a step farther, and considers insects in relation to 

 man, his person and property, either in so far as they affect his 

 industrial products, his cultivated plants, or the wild plants of nature. 



From a husbandry point of view, the science of economic ento- 

 mology may be divided into three principal parts — viz., garden pests, 

 farm pests, and forest pests. The last is obviously the most difficult 

 to deal with. 



Before any pest can be satisfactorily checked, it is indispensable to 

 study the life-history of the insect — viz., the egg, the larva, the pupa, 

 and the perfect insect, — and then to deal with that stage in which 

 the most practical results can be obtained. 



Hitherto it has been customary to study only those insects which, 

 by their numerical strength, have been injurious in the forest, but 

 I venture to think it would be far more interesting and educational, 

 either as an economic or a biological subject, to study all insects 

 which prefer an arboreal diet. To carry this out, two methods of 

 arrangement suggest themselves — viz., a botanical and an ento- 

 mological. With regard to the former, it would be necessary to 

 classify the respective trees, and then arrange those insects Avhich 

 feed on them. This method has been adopted by some American 

 writers. It has, however, this drawback, that while several insects 

 are fastidious as to their diet, others (except for the distinction 

 between hardwoods and conifers) are general feeders. Several 

 German writers follow an entomological method, and this course 

 appears to be far more educational to the student of forest 

 entomology. 



As the forest is a field literally teeming with varieties of animal 

 life, it may just be as well in passing to remind the practical husband- 

 man and general naturalist that there are numerous creatures in the 

 forest, under rotten bark and so forth, which are not in scientific 

 language insects. Such creatures are snails, centipedes, spiders, and 

 worms of various genera. 



Hence two questions arise — viz. : (1) What relative position do 

 insects occupy in the animal kingdom? and (2) What is an insect? 



As regards the position of insects in the animal kingdom, natur- 



