Evening star., 1949-10-05
This and That
By Charles E. Traceu,eH
CHEVY CHASE.

Dear Sir:
1--WE have had hundreds Of very little flies
in the house recently.
do you know what causes them, where
they come from, and how to get rid Of them?
II have examined everything closely from
the basement to attic and yet see no reason
for theul but there they are.
my admiration for their activity is great.
but that does not keep them from being q
nuisance, and would like to prevent further
invasions. They are not just ordinary house
flies. Sincerely, M. 0. L."
Ants, bees and wasps have four wings. the
flies and mosquitoes have two wings.
The name of the order to which they be-
long, the Diptera, means two wings.
These insects have just the one pair of
wings, and in their stead at the rear have
two balancers.
These balancers take the place Of the
semi-circular canals in humans.
If one is removed. the fly can still fly as
it wishes but with two gone it has no con-
troll over where it will 60.
There are all sorts of flies some large, and
some very small.
Our correspondents specimens come in
the latter category.
They are little flies that usually grow from
some vegetable matter Another careful
search Of the premises might find some cab
bage or other vegetable left in a bag, and
the heat has Matched out the larvae, COM
monty called maggots.
It does not take long for a forgotten bit
Of vegetables to let loose a veritable hoard
of these flies.
They are relatives of the tiny midges
called punkies in some sections. The bite
Of the punkies is severe, despite their size.
Usually the small flies found indoors are
harmless enough, and interesting on account
of their agility.
But no one wants them around of course.
Catching them, however, is a different
matter. Try as one will, it seems impossible
to swat them.
Attempts to slip up on them unaware
and trap them in tissue are unavailing.
because the little flies, though inert as the
tissue closes over them, are off and away
every time before the hand strikes.
Some other method of capture. then, must
be used, and here is perhaps the BEST Wait
until they have settled down on walls and
ceiling, after dark, then turn on the light
and use the long, snaky tube of the vacuum
cleaner on them. In this way they may be
taken in one by one, since this form of
capture is wholly outside their experience.
Their plan of waiting until the hand or
OCIler aTClCle OF Capture Is very close IallS
them this time, for the vacuum catches
them and draws them to destruction before
they are able to fly away.
Several days may be required to get them
all, in this fashion, but it Is the best way,
short of spraying, which has many disad-
yantages
Calls on trees are formed by both flies and
wasps
The pine cone willow gall is made by flies,
whose larva secrete fluid which causes an
enlargement Of the twig. Some of these
gals measure more than an inch in di-
ameter The larva Is in the gall all winter,
and after forming pupa matches out in
the spring.
Oak apples, so-called, are made by tiny
gall wasps, usually on the scarlet oak.
An egg is laid, and then the poison in
jected. It does not harm the egg, but causes
the branch to form an abnormal growthj
which protects the egg and resulting forms.
It is not known exactly whether the gall
apple" is caused as sort OF protest OF the
plant against the squirming Of the larva or
by the poison alone.
There also are oak apples on red and black
oaks Most of these are on the leaves. One
on the twigs is called the bullet gall. It Is
smaller. and appears mostly on the white
oak.