Scientific American Supplement, No. 492, June 6, 1885Various
Science
Scientific American Supplement, No. 492, June 6, 1885
Various
Science -- Periodicals
We have here an example of the direct relation of cause to effect,
although I am not in a position to assert that the effect is always
produced in the same way. To me there is no question as to the fact that
the constitution of those insects which nature has accorded the faculty
of liberating is strengthened, and that their chances of life are
increased, if the cold of winter is intense enough to plunge them into an
absolute rest, and is not unseasonably affected by warm, spring-like
days. It is certain that such cold is capable of contributing largely to
the multiplication of the individuals of such species as hibernate in the
egg state, and it also has a beneficent influence upon those species
which, like the small social larvae, pass this season upon the earth
enveloped in a silken envelope, or, like the larvae of the Noctuellae,
between dead leaves or upon the ground itself.
On another hand, it cannot be doubted that mild winters greatly
contribute to the bringing about of a destruction of larvae and chrysalids
in two ways: First, they favor the development of mould, which, as well
known, attacks the larvae of insects when these have been enfeebled by an
excess of rain or dampness; and second, they permit beasts of prey to
continue to exercise their activity. Now, these latter are numerous.
Moles, instead of burying themselves deeply, then continue to excavate
near the surface, and shrew mice are constantly in search of food. These
small mammals, which abound in this district, destroy a large number of
chrysalids of Lepidoptera.
It is the same with birds. As soon as severe cold begins to prevail in
the north and east, they come in troops to the open fields and the
sheltered slope of the hills of our district. But it is scarcely worth
while to stop to tell of the skill and perseverance of these destroyer of
larvae. We may mention, the woodpecker, however, as a skillful searcher
for insects that lie hidden in places where the sun has melted the snow.
The carnivorous Coleoptera and the Forficulae are likewise generally in
motion during mild winters. Doubtless these last-named do not make very
large inroads in the ranks of larvae and chrysalids every day; yet, having
no other food, they destroy a goodly number of them. But I believe that
the devastations made in the army of insects by all these enemies united
do not equal those made by certain crustaceans--the wood lice.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account