The St. Mary banner. (Franklin, Parish of St. Mary, La.) 1889-1931, 1906-12-08
A Peculiar Insect,

this caterpillar" asked John, on,
August morning, as he came in from
the yard bearing branch Of the Vir
Slnia creeper, with green caterpll
lar clinging to its leaves The worn
was so filled with what appeared Il
be tiny white. oblong eggs set on end
that only the head and tail of the crea
ture were visible
'Oh. l should say that he had a
good deal the matter" answered Aunt
Julia. looking closely at the caterpil
lar. In fact, he must feel very i'll
The poor thing has been the victim
OF a parasitic fly, belonging to the
1chneumonidae family. These tiny
cocoons with which he is covered have
been the work Of mischevious
lchneunOn fly, which some days ago
inserted her eggs under his skin, not
outstanding his wriggling protests.
The eggs soon Matched into minute
white grubs and immediately fastened
themselves upon the tissues OF the
caterpillar's body, so that now he is
compelled to eat for the whole fam.
lily"
Tell US all about 1t, Aunt Julia,"
said Helen, who had come out on the
porch to take a look at the worm.
What sort of insects are these
Ichneumon flies?"
! They are insects which are almost
wholly parasitic, most of the species
feeding. while in the larval state, upon
the bodies Of other insects. Many OF
them deposit their eggs within the
! bodies OF larvae either in wood or In
| the earth"
why. how do they manage to 10
that?" asked John.
THE Ichneumon flies" answered
Aunt Julia, "are able, by some mys-
terlous instinct to discover the exact
locality of hidden larvae, and, in
spite of all obstacles, to deposit their
eggs within it. The female of these
insects is furnished with sharp and
strong abdominal tube, or ovipositor.
which is capable of piercing almost any
substance. In some species this tube
is not thicker than q hair, but can
make its way through hard wood and
there act as channel through which
the egg is carried to its destination.
When the egg is laid upon the sur
face Of the larvae the parasites, as
soon as Matched, eat their way into J
their victim. When deposited insiae
the Ichneumons feed on the tissues Of
the body, gradually consuming its
life. and at length filling the body
with little cocoons Our poor cater
pillar here has had more than his
share. for it looks as though more
than one fly had taken advantage of
his plump proportions
will these Ichneumons feeding up
on him finally kill him, Aunt Julia?"
asked John, 'or will he recover"
ut is difficult to tell. After the tiny
black flies have left their cocoons he
may dwindle away and die, or he may
recover and reach the chrysalis stage
and complete his transformation into
gorgeous olive and red sphinx
moth"
Il have seen caterpillars before with
these white cocoons over them, but
never knew that they were the work
OF an Ichneumon," said Helen.
Eyes; beetles and caterpillars seem
to be the favorite victims Of these in
sects; and you might suppose that the
grub of a wondering beetle or moth
would be quite safe from external |
enemies SO long as 1t remained con- ,
cealed within the wooG. but by some /
strange instinct the Ichneum1.. ay dis
covers her prey"
Are these mischievous flies found I
all over the world, Aunt Julia?" in t
CURED John t
Yes; they are found in nearly all t
and about three thousand i
species have so far been discovered. t
many Of which are exceedingly small. 6
There Is certain species which abso-
utely swarms in the Canadian forests. i
may be found on the trunks v
If the trees dead after having deposit i
ID their eggs in the burrows made by s
some wood boring insect So In this p
'ase, as In everything else in nature. X
he Ichneumon has its use-in helping c
o preserve the forests from insec: de. t
'troyers. There is one genus in Aus v
ralia called megalyra or large-lyrc,' I
rom the resemblance to the strings k
Il Tyre, in the long ovipositor and c
he two sheaths which protect it." s.
II wish l could see some of these n
pecimens," said John. G
well, IL you are ever 80 fortunate
8 to visit London you can see a WON u
lerful collection at the British s.
luseum. In the meantime" said
lunt Julia, I'VE must keep our eyes Il
pen for what we can see in this coun. o
ry. And now what are you going to o.