INJURIOUS AND BENEFICIAL INSECTS. 525 
habits of insects for themselves. Unfortunately, also, so back- 
ward is the science of entomology in this country, that the atten- 
tion of its students is at present fully engrossed with classifying 
and describing the adult insects. When it is to be borne in mind 
that there are within the limits of the United States, probably at 
a low estimate, ten thousand species of Hymenoptera (bees, 
wasps, ichneumon flies, saw-flies, etc.), half as many butterflies 
and moths, about ten thousand species of flies, as many of bee- 
tles (Coleoptera) and of bugs (Hemiptera), and several thousand 
species of grasshoppers, etc. (Orthoptera), and neuropterous 
insects, such as dragon-flies, caddis-flies, etc., ete., the whole 
amounting to upwards of fifty thousand species of insects, to say 
nothing of the spiders, mites and ticks, centipedes and millepedes, 
it is evident that in the mere preliminary work of identifying 
and properly describing these myriad forms—an intellectual 
work requiring as much good sense, discretion and knowledge 
as shown in the pursuit of medicine, the law or education,— 
that all this work, which is simply preliminary in its nature, is a 
vast one, and that the combined exertions of many minds over 
Several generations will not exhaust the subject. As it is, there 
are in this country only about thirty entomologists who publis 
anything relating to insects. Necessary as it is, this work of clas- 
Sification is by no means the highest and most useful branch of 
physical science. He who studies carefully the habits and struc- — 
ture of one insect, and, if injurious to agriculture, lays before the 
farmer and gardener a true story of its mode of life, is a true bene- 
factor to agriculture, and at the same time benefits science more 
than he who describes hundreds of new species. Such an one 
was Dr. Thaddeus W. Harris, whose leisure moments were conse- 
crated to the benefit and advancement of the agricultural interests 
of our state, and the commonwealth perhaps never made a better 
investment than in supplying the agricultural community with an 
illustrated edition of his immortal work. On looking over Dr. 
Harris’s work we find that he mentions about six hundred species 
as injurious to vegetation, and as others have been added since 
then, it is not improbable that we have at least one thousand 
destructive species, i. e., about one-tenth of the entire number 
(10,000) of insects which undoubtedly are to be found living 
within the limits of this state. As to the losses sustained from 
their attacks it would be difficult to say how great they are, but it 
