Over the past week, out house has been infested with big
houseflys! I am killing 10-15 in one swipe! It only tends to be
during the day with the light coming through the windows, but it been
going on for 3 days now and they just keep coming! Where are they coming
from and why are they so huge? I feel like maybe I've been keeping a
fithly house, but I know it's clean. Please help me to understand what
is going on. This is the first time I have ever seen so many in my
The way to deal with any insect infestation is first to get rid of the
adults and then remove the children and the place they will/can develop.
Seeing that you are swatting 10-15 per swipe of the adults, you have step
one in progress. Continue removing the adults as you find them and you
lessen their opportunity for reproduction.
The second mode of attack is to remove any and all opportunities for
development of their young. If you recently brought into the house any
organic materials from outside, or anything containing a niche where the
young can develop, return it to the outdoors. For potted plants you may
have brought again indoors, replace the potting soil with new soil from a
garden center. Be sure to dispose outdoors any and all plant medium where
the flies may have laid their eggs. Mulch also is a breeding ground for
flies and their larvae. Be sure to be extra conscious to remove any
potential food source. Bananas and any fruit should not be left out on the
counter (store it in a Rubbermaid type container. Be sure not to leave open
access to any source of water (don't leave glasses in the sink holding
water, for example.) Assuming you get rid of all the niche/food sources and
you continue to kill adults as they emerge, you will see the population drop
Finally, make sure any access to the outdoors is sealed. Both in your
living area, as well as attic or cellar, make sure the insects are not able
to enter in seek of warmer quarters for the winter.
Thanks for using NEWTON!
Richard R. Rupnik
There are many species of flys, different sizes.
If you have a "sudden" invasion of flys they are probably maturing from some
breeding spot that has gone unnoticed for a few weeks, somewhere in or very
near your house, in a hidden spot that you overlooked, was something organic
that flys could lay eggs on and the larvae feed and mature. If there is a
way for them to come in from outside, at this time of year, they will do
that; if not then the source was probably somewhere inside; no matter how
well you clean no one is perfect and it doesn't take much. Once this "hatch"
is gone - you've killed them all - if there is no new place for them to lay
eggs you probably have nothing more to worry about.
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Update: June 2012