Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1915-09-14
The Flight Of Files.


Ono of the problems that has arisen In
connection with tho part played BY in
scots a carriers Of disease concerns the
distance which they may be able TO travel
from ono locality to another. This has
frequently been considered In this coun-
try in connection with mosquitoes which
are responsible for the prevalence OF
malaria. With their breeding places
known, 1t has become desirable In some
cases to ascertain what the range OF their
activities might be In respect to the ter
ritory which can be covered by insects.
It has been learned that mosquitoes
which inhabit salt marshes near the Sea-
coast may be found inland Ut distance
as great ~ three miles.
Far less appears to be known with re-
gard to the migrations of the common
house.fy, an insect charged with respon-
sibility for typhoid fever and other infec-
tious diseases. A series OF studies con-
Quoted in Cambridge. England, on the
range OF the fight Of flies OF this species
has been made the subject OF report to
the Local Government Board on Public
Health and Medical Subjects. Upward
of q, 200 flies were liberated, under varl-
GUS meteorologic conditions, from the
medical buildings at Cambridge. OF
these insects, colored for Identification,
19l were recovered. The results showed
that house. flies tend to travel either
against or across the wind. The actual
direction followed may be determined
either directly 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 superstition is the
nature of the station at which flies were
recovered after they had travelled any
distance. These comprised butchers
shop, public houses and restaurant. all
of which gave off odors that are notori-
ously attractive to flies. The chief con-
ditions favoring the dispersal of flies are
fine weather and q warm temperature.
The nature OF the locality is another con-
siderable factor, because In towns flies
do not travel as far as In open country,
probably due to the food and shelter af-
forded by the houses. With regard to
the altitude of the point of liberation,
flies set free from the roof tended to dis.
perse slightly better than those liberated
from the ground, but the differences are
not very considerable. 1t has been OBJ
served, with regard to the vertical flight
of the house fly, that it may mount al.
most directly upward to q height OF
forty. five feet or 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 we'll
"a when liberated in the morning.
The maximum fight observed In the
thickly housed localities in Cambridge
was about quarter of mile. In one
case, where part of the distance was
across open fenland, flight Of TO yards
was noted. In experiments conducted
in Cook County, Illinois, by s. A.
Forbes, flies were trapped aud, after be-
ing sprayed with chemical solution for
recognition, were liberated from hos
pital in that district. They too we're
recovered at distances ranging up to q
quarter of mile from the point OF liber-
alton. The distance flies may travel to
reach dwellings Is controlled by circum-
stances. Almost any reasonable distance
may be covered by the fly under compul-
sion to reach food and shelter.