52 INSECTS. 
ity with which many kinds of insects increase, if allowed tu 
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 
gand 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 
ard fifty millions in the third generation.* To take another 
example the aphides, or plant lice, which are frequently seén in 
great numbers on the tender shoots of fruit trees have an almost 
incredibly prolific power of-increase,—the investigations of 
Réaumur 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 suffer great injury, or total loss, from the 
want of a little timely care. ST 
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 difference 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 suffer greatly, is 
thus preserved, by half an hotir’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 ina 
single moment. In default of other more rapid expedients, the 
old mode of hand-picking, and crushing or burning, is the safest 
and surest that can be adopted. ‘ : 
. * For much valuable information on the habits of insects injurious te 
: vegetation, see the Treatise on the Insects of Massachusetts, by Dr. T. W 
Harris, Cambridge, , ; 
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