cause of an evil for which he pays so heavy a penalty.
Insects increase whenever the birds which feed upon
them disappear. Hence, in the wanton destruction
of the robin and other insectivorous birds, the bipes
implumis, the featherless biped, man, is not only exchanging
the vocal orchestra which greets the rising sun for
the drowny beetle’s evening drone, and depriving
his groves and his fields of their fairest ornament,
but he is waging a treacherous warfare on his natural
allies.
[Footnote: In the artificial woods of
Europe, insects are far more numerous and destructive
to trees than in the primitive forests of America,
and the same remark may be made of the smaller rodents,
such as moles, mice, and squirrels. In the dense
native wood, the ground and the air are too humid,
the depth of shade too great, for many tribes of these
creatures, while near the natural meadows and other
open grounds, where circumstances are otherwise more
favorable for their existence and multiplication,
their numbers are kept down by birds, serpents, foxes,
and smaller predacious quadrupeds. In civilized
countries these natural enemies of the worm, the beetle,
and the mole, are persecuted, sometimes almost exterminated,
by man, who also removes from his plantations the
decayed or wind-fallen trcea, the shrubs and underwood,
which, in a state of nature, furnished food and shelter
to the borer and the rodent, and often also to the
animals that preyed upon them. Hence the insect
and the gnawing quadruped are allowed to increase,
from the expulsion of the police which, in the natural
wood, prevent their excessive multiplication, and
they become destructive to the forest because they
are driven to the living tree for nutriment and cover.
The forest of Fontainebleau is almost wholly without
birds, and their absence is ascribed by some writers
to the want of water, which, in the thirsty sands
of that wood, does not gather into running brooks;
but the want of undergrowth is perhaps an equally
good reason for their scarcity.
On the other hand, the thinning out of the forest
and the removal of underwood and decayed timber, by
which it is brought more nearly to the condition of
an artificial wood, is often destructive to insect
tribes which, though not injurious to trees, are noxious
to man. Thus the troublesome woodtick, formerly
very abundant in the North Eastern, as it unhappily
still is in native forests in the Southern and Western
States, has become nearly or quite extinct in the
former region since the woods have been reduced in
extent and laid more open to the sun and air.—Asa
Fitch, in Report of New York Agricultural Society for
1870, pp. 868,864.]
Introduction of Insects.
Copyrights
The Earth as Modified by Human Action from Project Gutenberg. Public domain.
