The Leon reporter. (Leon, Iowa) 1887-1930, 1911-07-13
HOW FAST FLIES BREED.
Figures That Stagger the Mind Are
Produced by Experts.

PRODUCED by Experts.
In the old Rays third part arith-
metic there were examples that act
ually staggered the mind. Such as
the familiar one concerning the num-
Der of changes to be wrought with
the alphabet, or that of the Shah of
Persia, who offered the inventor one
grain of wheat for the first square
on the chessboard, two for the Sec
ond, four for the third, eight for the
fourth and so on. But the fly seems
to have all these calculations beaten
to FRAGILE.
AS the Hawk-Eye explained in the
sixth article of this series, it takes,
with average conditions, ten days
from the laying of fly's egg to the
emerging of the adult fly. 1t takes
about ten days more before the fly
begins to lay it's eggs.
Though the flies continue to issue
from rubbish piles after early Sep
TENDER, sometimes even into Novem-
Der, the chance for breeding between
April 18th and September 10th is
bad enough, and gives us ten fly
generations.
DIR. Leland O. Howard, the chief
of the governments experts on flies,
has carefully estimated the number
of flies which would be born were
none destroyed before egg laying.
He says: This number of genera
tions has a direct bearing upon the
number of flies, not only at different
periods during the summer, but also
in the early autumn, since there is,
barring accidents, constant and
course some summers are warmer
than others and some are moister
than others, and upon these two fact
ors, taken in connection with that of
available places for breeding, the
number of flies must depend.
Take for example, the possibili-
ties in Washington, and let us esti-
mate, on the basis of survival of all
eggs and all individual flies, upon
plenty of places for the insect to
develop and for the larvae to feed,
upon an average of ten days to gen.
Grafton in midsummer (this period
increasing in the autumn and being
greater also in the springtime), and
q
emerging of the adult flies before
sexual maturity is gained (this point
of the duration of the existence of
the adult fly before the attainment
of sexual maturity has been the weak
element in other calculations that
have been made of house fly abund-
ance) let us start on April 18th
with a single Overwhelming fly
which on that day lays 100 eggs, and
we will have the following table:
April 18th, the Overwhelming fe-
male fly lays 100 eggs.
May LIST, 120 adults issue, of
which 60 are females.
June Sth, $500 females lay 100
eggs each.
May 2Sth, 1900 adults issue, of
which $500 are females.
June sth, $500 females lay 100
eggs each.
June goth, $4,000 adults issue, of
which 216,O00 are females.
June Goth, $1,000 females lay 1870
eggs each.
July 10th, 25,92O,00O adults is
sue, of which 12,96O,O0O are females
July 10Th, 100000 females lay
100 eggs each.
July 10th, 1855, 100000 adults is
sue, of which 777,600,0Oo are fe-
males.
August Sth, 777,600,OOO females
lay 120 eggs each.
August 18th, 1892, 100000
adults issue, of which 1855, OOO,-
900 are females.
August 2sth, 1856, 100000 fe-
males lay 100 eggs each.
September 10th, 5,59S,720, 0O0,-
600 adults issue, of which one-half
are females.
(From the House Fly-Disease
Carrier" by DR.. L. o. Howard. Copy
right 1911, by Friedrich A Stokes
Company
Such figures make one feel that
we can never even begin to combat
the house fly. But, of course, they
suppose that all the eggs hatch, that
none of the larvae is killed, and that
all the flies lay eggs before they die.
of course, huge per cent
Of them do not But these figures
flies possible, and the earlier the
better; for in killing one we kill not
only one but countless millions.
That theoretical estimate is not
is shown by the fact that
4 scientist of the university of Cali
fornia, by counting the larvae and
eggs in part and estimating the rest,
found a total of 455,0O0 larvae in
4 single large pile of manure weigh
ng about 1000 pounds; Mayor N.
Faichnie, of the Royal Medical corps,
estimated 1000 flies from one-sixth
cubic foot of trench ground; while
another scientist has found 200 fly
ouparia in less than one single foot
If manure!
One fly lays eggs on April 18th.
On September 10th, $685. 0,000,-
100 flies are born as descendants of
hers, if none gets killed. Doesn't it