8 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



GROUPS OF ANIMALS STUDIED BY THE ECONOMIC ENTOMOLOGIST. 



It has been my custom in pointing out to pupils the extent of the 

 class Insecta and its relations with other groups of animals to remind 

 them that our legitimate field covers the three classes of Arthropods — 

 namely. Arachnida, M}^riapoda, and Insecta, and that occasionally 

 a venturesome entomologist pushes on into the fourth group when 

 some member of it, such as the pill bug, becomes troublesome and 

 requires attention from a practical standpoint. Considering the num- 

 ber of species of true insects alone to be studied — and any one of 

 them may demand attention — the economic entomologist occupies a 

 greater territory than do all his fellow-workers in mammalogy, orni- 

 thology, ichthyology, herpetology, malacology, etc., put together. 



Compared with other groups of animals, the Insecta at once 

 stands out as the most conspicuous, both in point of numbers and of 

 species. Mammals, birds, reptiles, and fishes, composing the verte- 

 brate subkingdom, include but few, relatively. Mollusks are not 

 especially numerous. The same is to be said of the true worms, of 

 the starfishes, and the sea urchins. Of the corals, sponges, and 

 microscopic Protozoa, also, it may be said that their numbers are 

 small as compared with those of insects, though the Protozoans, 

 especially those of salt water, exist in amazing numbers of individ- 

 uals. Insects, numbering, it is believed, about 1.000,000 species, sur- 

 pass all these other groups, and constitute approximately four-fifths 

 of the whole animal kingdom. Here is a great field for the entomo- 

 logical taxonomist, and it is this wealth of material that has kept 

 entomology somewhat behind botany and some other branches of 

 biological study. To describe properly the adults alone of all these 

 species of insects would require 2,000 octavo volumes each of 500 

 pages. To describe the life history of any insect should require at 

 least two octavo pages, which would add tt.OOO volumes more, and 

 perhaps another thousand would give adequately the facts relating 

 to the habits and distribution of each species. Good accounts of the 

 morphology and physiology of typical examples, even of family 

 groups, would add many more volumes. Then we must include as 

 part of the domain of the entomologist the classes Myriapoda and 

 Arachnida, comprising, say, 10.000 species. A library of not less 

 than 7,000 volumes would thus be required to give merely the im- 

 portant facts concerning existing insects, not including discussions 

 of remedies for insect injuries. 



ALL INSECTS OF ECOXOMIC IMPORTANCE. 



It may be said of the 1.000.000 insect species estimated as now 

 existing that they are every one in greater or less measure of interest 

 from the economic view-point. If carnivorous, they feed upon one 



