The Washington times., 1921-11-06

TOW far will houseiy fly from the
RI place where it was hatched? And
q 4 how fast can 1t travel?
These are questions which the Govern.
ment Bureau of Entomology has been try
ing to solve by some very interesting ex-
periments conducted in the neghborhOod
OF Fort Worth Texas. They have an i'm
portant bearing upon the distribution OF
diseases. such as typhoid fever and tuber-
culosis, which the housefy carries.
The experts caught in traps great num-
bers OF flies, painted them red, let them
60 and set recovery traps" at various dis
tances from the place where they were
liberated, to find out how far and how
fast they would travel.
In q series of such tests $4,000 flies
we're liberated-houseflies, blowfies,
stable flies and screwworm flies all Of
which are economically injurious species,
communicating diseases to man or domes-
tic animals. The longest journey noted
for the housefies was over thirteen miles.
Some of them covered six miles in less
han twentyfour hours.
Most important of all were the tests
for the housefy's flying power That
insect is recognized to-day as the
most dangerous of all the enemies of man
kind. Just for one item. it is responsible
lor half the deaths from typhoid; and the
filth germs il carries (say the metropolitan
health authorities) destroy the lives Of
600 children in New York annuaily-vic.
tins OF Summer diarrhoea and other intes-
tina, complaints.
The houseAy is the cleverest Of insects,
its intelligence far surprising that OF the
ant and the bee.
It can think 100 times quicker than
man. IL you want evidence Of that, OBJ
serve the lightninglixe promptness with
which It lodges blow Of your hand.
Its huge compound eyes, each compriS.
ing thousands of little eyes provided with
distinct and separate lenses and retinas.
are magniiers for seeing microscopic OBJ
jects close at hand. Above and between
these, on top OF its head, are three single
eyes, set in a triangle. for longdistance
vision.
Gifted with marvellous activity, the
iousefy is one of the most powerful AMI.
mails we know, muscularly
Its sense OF smell is wonderfully keen.
Odors of cooking are what fetcheS IT into
cur houses, seeking food
housefy is always seeking two things
food and a suitable place to breed. For
the latter purpose 1t requires filth OF some
sort. II feeds on nastiness, when handy
Sputum, for example. Thus II is carrier
Of filth germs. which It brings to our tables
end introduces into the babies milk.
The only way to get lid OF flies Is to
render filth inaccessible to them; they
cannot breed without it, Hence the i'm
portance OF locating and dealing with the
unpleasant sources Of hy supply. In order
10 undertake this work successfully II is
very desirable to know how far lies can
Ay--a point which has an obvious bearing
upon determination of the area over
which the work must be extended in any
given neighborhood in order to insure
satisfactory results
Hence, then, the experimental inquiry
recently undertaken In Texas.
The method adopted was TO bait large
conical fy.traps with gut slime" obtained
from packing houses. All the flies taken
we're captured in packing houses at Fort
Worth and Dallas. From the traps they
we're transferred to cylinders Of wire net,