The Barre daily times. (Barre, Vt.) 1897-1959, 1914-12-30
THE FLIGHT OF FLIES.
Some Interesting Experiments Have
Been Conducted.

One of tile problems that has arisen il
connection with the part played by in
sects as carriers of disease concerns the
distance which they may be able tc
travel from one locality to another, This
has frequently been considered in this
country in connection with mosquitoes
which are responsible for the prevalence
of malaria With their breeding places
known, it has become desira BILE in some
cases to ascertain what the range OF
their activities might be in respect to
the territory which can be covered by
insects. 1t has been learned that mos
quitoes which inhabit salt marshes near
the seacoast may be found inland at a
distance as great as three miles.
Far less appears to be known with re-
gard to the migrations of the common
house-fy, an insect charged with re-
sponsibility for typhoid fever and other
infectious diseases A series OF studies
conducted in Cambridge, England, on the
range of the flight of flies of this species
has been made the subject of a report to
the local government board OF public
health and medical subjects. Upward of
$4,000 flies were liberated, under vari.
Gus meteorologic conditions, from the
medical buildings at Cambridge. OF these
insects, coored for Identification, l9l
were recovered The results showed that
house-hes tend to travel either against
or across the wind. The actual direction
followed may be determined either di-
rectly and by the action of the wind,
or indirectly owing TO the flies being
attracted by odors from food. A point
in favor of this supposition is the nature
OF the station at which flies were recov
cred after they had travelled any dis
tancc. These comprised a butchers shop,
public houses and restaurant. all of
which gave Off odors that are notorious
~ attractive to flies The chief conditions
favoring the dispersal OF flies are fine
weather and a warm temperature. The
nature Of the locality is another consid-
cradle factor. because in towns flies do
not travel as far as in open country
probably due 10 the food and shelter
afforded by the houses With regard TO
the altitude Of the point of Liberation,
flies set free from the roof tended TO
disperse slightly better than those lb-
,nccs are not very considera Ne il has
been observed. with regard 10 the YER
teal fight OF the house-hy that il NAV
mount almost upward 10 a height Of
forty-hve feet OF more. The time Of day
appears TO influence the dispersal of the
insects, as. apparently. when set free in
the afternoon they do not scatter 80
well a. when liberated in the morn
ing.
The maximum flight observed in the I
thickly housed localities in Cambridge 4
was about a quarter Of a mile. In one 4
case. where a part Of the distance was 4
across open feulrnd, fight Of no yards 4
was noted In experiments conducted 4
IN Cook county. Illinois by = A. Forbes 4
flies we're trapped and. after being spray
ed with 4 chemical solution for recogni-
ton. were liberated from a hospital in
that district They too mere recovered I
% distances ranging up 10 quarter Of
q mile from the point of liberation The
distance flies may travel 10 reach dwell.
lings j. controlled by circumstances AZ
most any reasonable distance may b.
covered hy The ~ under compulsion to
reach food and shelter