52 INSECTS. 



ity with whicli many kinds of insects increase, if allowed to 

 get well established in a garden, to become fully aware of this. 

 The common caterpillars are the young of moths or butterflies, 

 and that careful observer of the habits of insects, Dr. Harris, 

 says as each female lays from two to five hundred eggs, a thou- 

 sand moths or butterflies will, on the average, produce three 

 hundred thousand caterpillars ; if one half this number, when 

 arrived at maturity, are females, they will give forty-five millions 

 of caterpillars in the second, and six thousand seven hundred 

 and fifty millions in the third generation.* To take another 

 example the aphides, or plant lice, which are frequently seen in 

 great numbers on the tender shoots of fruit trees have an almost 

 incredibly prolific power of increase, — the investigations of 

 Reaumur having shown that one individual, in five generations, 

 may become the progenitor of nearly six thousand millions of 

 descendants. With such surprising powers of propagation, 

 were it not for the havoc caused among insects by various species 

 preying upon each other, by birds, and other animals, and espe- 

 cially by unfavourable seasons, vegetation would soon be entirely 

 destroyed by them. As it is, the orchards and gardens of care- 

 less and slovenly cultivators are often overrun by them, and 

 many of the finest crops suff'er gi-eat injury, or total loss, from the 

 want of a little timely care. 



In all well managed plantations of fruit, at the first appear- 

 ance of any injurious insect, it will be immediately seized upon 

 and destroyed. A few moments in the first stage of insect life — 

 at the first birth of the new colony — will do more to rid us for 

 the season, of that species, than whole days of toil after the mat- 

 ter has been so long neglected that the enemy has become well 

 established. We know how reluctant all, but the experienced 

 grower, are to set about eradicating what at first seems a thing 

 of such trifling consequence. But such persons should consider 

 that whether it is done at first, or a fortnight after, is frequently 

 the diff'erence between ten and ten thousand. A very little time, 

 regularly devoted to the extirpation of noxious insects, will keep 

 a large place quite free from them. We know a very large 

 garden, filled with trees, and always remarkably free from insect 

 ravages, which, while those even in its vicinity suff'er greatly, is 

 thus preserved, by half an hour's examination of the whole pre- 

 mises two days in the week during the growing season. This 

 is made early in the morning, the best time for the purpose, as 

 the insects are quiet while the dew is yet upon the leaves, and 

 whole races, yet only partially developed, may be swept off* in a 

 single moment. In default of other more rapid expedients, the 

 old mode of hand-pickinr/, and crushing or burning, is the safest 

 and surest that can be adopted. 



* For much valuable information on the habits of insects injurious to 

 vegetation, see the Treatise on the Insects of Massachusetts, by Dr. T. W. 

 Harris Cambridge. 



