American citizen. [volume] (Canton, Miss.) 1864-1890, 1875-08-28
The Strength Of Insects.

SOME interesting and ingenious expert
| ments for measuring the strength of in.
sects have lately been made by a Belgian
naturalist named Plateau. He first tested
their power of raising weights while walk.
| ing on a level surface. His novel method
| of doing this was to harness the insect by
a horizontal thread running over an easily
moving pulley, at the other end of which
was attached a scale pan for holding sand
| To keep the insect in a straight direction
he fenced it in between two parallel strips
of glass; and to keep it from slipping he
| covered its track with coarse muslin As
the insect moved forward it pulled the
thread over the pulley and raised the pan,
and the experimenter poured sand into il
until the insect could move forward no
| longer. The insect and the sand 1t had
raised were then eighed, and the relation
between the weight of the two was OBJ
| tanned He found that the insect could
| raise forty times its own weight; while by
| a similar method a man could raise only
five-sixths of his weight, and horse only
one-half or two-thirds of his. by repeat
ing each experiment three times and EN-
plOying vast number of insects of varl-
Gus sizes and comparing his results, he
came To the conclusion that the smaller
insects in the same group invariably raise
the greater weight in proportion to their
own weight.
He then tried their leaping power, by
fastening the wings and elytra, and by sus-
pending under the therax (by tfread)
bits of lead set in wax. He increased the
weight till the insect could no longer raise
it. Then, by his determinations as before,
he found that, while the largest crickets
could raise in this way only about one and
a half times their own weight, the smaller
ones could raise three or four times theirs
To test the pushing power of insects he
placed some of them in a long cardboard
tube blackened on the inside and admitting
light only by transparent glass at one
end. To this glass was attached lever
which drew the scale-pan over the pulley,
as in the first eXperimen The insect, in
its endeavor to escape, pushed against the
glass, moved the lever, and thus raised the
weight. AS results of these experiments
he found that, i'm inverse ratio to their
weight, the pushing power varied from
three or four to eighty or ninety times the
insects weight.
The power OF flight possessed by insects
was tested by fixing weights to the body in
the same way as IN leaping. He found
that they employ much less force in flying
than in other efforts of strength; perhaps
this is because, unlike birds, they are not
intended to carry weights through the air.
Beetles raise in flight from one-sixth to
twice their weight; flies, three times their
weight. A drone weighs four times as
much as bee, and drags less than fifteen
times its weight, while the bee drags
twenty-three or twenty-four times her
weight. But in flying the bee raises
nearly her own weight, while the drone
raises a weight equal To only half its own.
By these experiments he found that his
law applies equally well, whether the
strength is exerted in walking, leaping,
pushing or flying. He finds that it also
applies, i'll a measure, to the entire class
of insects taken together, well as to the
same group of insects taken by themselves.
There are some exceptions to this, however,
which are probably due to differences of
structure. By dividing all the insects into
three groups-lightest, medium and heavi
cst-he finds that the law holds good. Then
the relative force is represented by the
numbers &c, 10 and 0 respectively. The
fact seems to be that the strength of an in
sect increases with the surface of sec
ton and not with the volume of its
muscles. This would make the weight
increase faster than the motive power and
be consistent with the law that the small
est are strongest. 1t takes but a moments
reflection to see the wisdom Of this ar
rangement. OF course the hardness Of
the soil, the weight of the grains Of sand
and all the resistance to be overcome are
equally great to the small as to the large
insects, -and-it- needs greater relative
strength to give the small ones a fair
chance in the " struggle for existence"
with their larger associates,