Lancaster daily intelligencer. [volume] (Lancaster, Pa.) 1864-1928, 1880-09-21
SCIENTIFIC CORREsPONDENCE.
The Long Stiused Ichneumon.

-Ss@~0S~ AS..AsOseA~~.s
DEAR SIR: I enclose you what is said to
tree in Walnut street, Of this town. The
party who caught it says that he has seen
as many as twenty ut one time ON the trunk
Of the tree mentioned, all busily boring
holes, buS at the time he went to capture
one of them for me, he only saw one which
is the one enclosed, and which he says is
only half the size Of most of them. You
will find that tho head is severed from the
body, having been done 30 by the party
who caught it he being afraid of it. He
says it does the boring with the long caudal
appendage that he, with probably TWEEN
ty others, watched them working great
while, but they all seemed afraid to mOlest
them. visited the treo this afternoon
and found the whole trunk perforated with
holes from an eighth 70 q quarter Of an
inch in diameter. l will visit the place
again, when probably can secure q larger
and more perfect specimen. We are anx-
iOus to know what it is Lot us her from
you soon.
Yours, &c. CIR.
Columbia, Sept. II, 1880.
Answer.
Your fagmentary specimen was received
this morning. Although mutilated, still
there was sufficient Of it undamaged to en-
able me to identify it. 1t is one Of the
Lons-stinged 1chncumon fiies"-the
Pimpla (Rhyssa) lunator Of entomolOgists
The family QCENEUMONIDG) to which it
belongs, includes q very large number Of
species, but this species and the dtrate
possess the longestovipositors. Practically
the long caudd appendases you allude to
is not sting Or stmgs, but simply mOdi-
tication of the sting OF other families of the
same order. The insect is entirely HARM
less and may be handled with perfect i'm
punity. The insect is parasite, and did
not bore the holes in tho tree which you
say you saw.
These holes were previously bored by
some other insect in its larva state-per-
haps 4 species of Iremer, Sirer, Clytus,
EldphidcOn, Or some other wood boring
larva; and the instinct Of the Pimpla
taught it that there were grubs in the old
tree, which would be \ proper place to de-
pOsit al egg Or two, and it availed itself Of
its normal relations to the host inside.
Where the host is within reach Of the
ovipOsitOr they reach it through the aper-
ture already existing but where it is too
far off to be thus reached they penetrated
the wood, and their instincts unerringly
teach them where to penetrate. The owl
positOr of these insects is composed Of
three parts-twO outside sheaths and
central saw or rasp, with which they saw
or rasp q small aperture, pushing the two
sheaths inward as the pipes arc introduced
into an artesian we'll. Having reached the
grub inside, they deposit one or moro eggs
into its body (according to its size),
and these eggs are Matched, the
young Pimplas feed upon tho carcase Of
tho grub. From this habit they are
also called "cuckoO flies that is, they
have no hole and make no nest of their
own, but trcspass upon the premises of
other insects and feed upon the bodies of
their young. Sometimes, when the wood
is hard, they are unable to Withdraw the
Ovipositor, and die in that position. l have
often taken them in that condition. When
they pass through all their transformations
and are ready to emerge as fully devel-
Opcd pimpla or cuckoo fly, they generally
come out through the aperture made by
their host, but if that should be impracti-
cable, they have sufficient mandibular
power to cut their way out by shorter
process. They seem to be partial to tho
larva of the ''Pigeon Tremcx" (1remer
Cozumba), which usually bores into dead
or decayed wood, but l have captured
them fastened to pretty solid oak wood,
and when the host inside was probably the
grub of the ''HOrned Passalus" (Rtssalus
cornutus). They are classed among innocu-
Gus insects, or insect friends. X.