Evening star., 1886-07-17
CITY AND DISTRICT.
~ ASenxer Appears in the Form of a
Very Active Fly.

To the Editor of THK EVENING Sr.K
The ioes who make the most noise are the
ones the caterpillar has the least cause TO fear
for while he i being assailed by newspaper
squibs and hard epithetS he calmly goes OH
Chewing up trees and preparing tor the next
generation But an avenger has come. Go TO
an infested tree and you will tie caterpil-
lars crawling ON the pavement, or on the box
or tree Now watch u moment. Here comes a
NY, closely resembling "A common house-fiy but
ItrgeT-may he twice as large. He aIightS near
n caterpillar and makes 4 quick dart ut him.
runs in 'front.' of him and darts at him again At
the first attack the caterpillar tries to escape
then he jerks his head violently, throwing ii
nom side to side, and evinclng the utmost fear
Oi his active little assaiianL soon he begins To
twist and turn, putting himself into the queer
est attitudes. and performing the most curious
cOutOTtIOns, while the hy, "a if satisfied that he
L. all right, gOes on To- waylay the next one.
now what does All TINS mean? By look ing
closely you III see "A number of minute while
sp-cks attached tO the caterpillar. and the con-
tortIOns he makes his efforts to- rid
himself of them, which he often seems able
10 do IL they are placed TAR enough back on his
body tO enable him To- reach them; but the fly i
aware Oi this, and confines lis attacks Chiefly tn
The head and neck iii caterpillar has "A neck
These speckS are eggs, and at every successful
dart oi the NJ II rrmly likes one TO the cater
pillar. making hIm the Matching house, nurse.
and food ct lis offspring. which. while "a very
good arrangement Tor the fly, Is extremely
uISa.reetble to- the caterpillar as it not only
upsets lis own family intentions. but forces
him TO become an unwilling sacrifice To his
enemy. These eggs are white, oval. and about
tine One-nitieth Oi an inch tesIImaTed in their
longest diameter, and when m;,nified are very
beautiful Things 1t is Interesting To watch the
efforts Oi the caterpillar To avoid the attacks of
the ny, and 10 rId himself oil the egg, the di,siS-
trOus effects OF which he seems Iully To under
stand 4 he skill displayed by the IL Is equally
As curious, as IL evidently seeks 10 deposit its
e.gs where they will be less liable be re-
moved.
would be much pleased if some of our profes-
slOnal cntOmOiOsI>ts To whom this Is doubtless
familiar, would tell us all about 1.-THE manner
Oi deN eiOpnrnt of the egg and the effect on the
caterpillar. A most interesting question comes
ny hoIe. which cannot Heip tOucnIug-tIe in
stlnct which leads "A caterpillar To- lear fly he
has never seen before, ana to avoid ii danger of
which he knows nothing by personal expert
ence. Ii the eggs cause the death OF the Cater
pillar, offspring he ielt to inherit ills lear
or profit by IT. experiences; but that the cater
pillar does have "a dread OF the hy any can
be convinced by observation. The fly Is also
evldehtIy aware that all egg placed the
head neck Ol Il caterpillar is safer from re-
moNal than one placed further back the
body. and this he knows we'll the first time
he tries al any time, for the life oil both ii
and caterpillar il too short for experiment or
experience. In order to appreciate what have
written or the interest attaching To this ques-
tOn oi instinct aud heredlty one wants to see
IL Tor himself. l. u. VI.