Kill all houseflies: Is there a downside?

[Largo62]

While shooing away flies from food or from my ears (to which the little buggers seem to be unaccountably attracted), I sometimes imagine being able to magically wipe out the entire genus and all its hundreds of species.Actually, I imagine with some glee being able to kill each of them individually.

Any entymologists or ecologists out there? This question has been “bugging” me. If there were some way to wipe out the world population of musca domestica would there be a negative consequence? I’ve already considered the increase in human population due to the dramatic reduction in diseases like typhoid, but I don’t want to go into a debate on population control here. What I’m thinking of now is, would there be a concomitant reduction in other species that eat flies, throwing the ecological balance off in a way that would harm nature as a whole or people specifically?

I searched Cecil’s columns on flies, but this particular question wasn’t addressed. I don’t care how flies land upside-down on a ceiling. All I care about is killing them, which seems to be futile. Anyway, if it could be done, should it be? Why? Why not?

[Tuckerfan]

Well, it would slow the process of decay since flies like to land on dead things/feces, eat it, and lay their eggs in it (so that their larva have something to munch on when they hatch). Plus, it’d make it difficult for people to determine the time of death (since the life cycle of the fly is used in cases where a body’s been found in the woods).

No doubt some other animals would starve to death due to a lack of food as well. (Since flies comprise the principle diet of some spiders, IIRC.)

[xcheopis]

…flies comprise the principle diet of some spiders

But is there a downside?, said the arachnaphobe.

Not all spiders eat flies; some will eat anything that they catch (and spiders can get quite large), others only eat gnats or mosquitoes, etc.

The juvenile form of houseflies (and all members of the Order Diptera) is completely different from that of the adult form and they have different nutritional needs. (This prevents competition for food between juveniles and adults.) Many larva feed off decomposing biological matter - both plant and animal - which aids in getting important nutrients back into the soil for prokaryotes, fungi, and plants.

However, they are not the only decomposers and I, for one, wouldn’t miss them for a minute. I don’t know what the net ecological impact would be if all house flies disappeared but I suspect their place would eventually be filled by another species.

[Johnny_L.A]

I once read a science fiction book called The Texas-Israeli War. In one part an Israeli tank crew stops at a rest area off of an interstate. There was “something wrong” – no flies. Without people leaving garbage, there was nothing for flies to eat and they went away. Of course flies existed before people, so doing away with people wouldn’t work. (And if it did, who would know?)

How about getting a bunch of spiders to live in your house?

Geckos, perhaps?

[Netbrian]

What would happen if extincted all the mosquitoes?

[Violet]

Looks like some flies kill fire ants, which are a problem in Texas. See http://www.utexas.edu/admin/opa/news/99newsreleases/nr_199906/nr_ant990615.html

Gilbert said that during the Memorial Day weekend, he and Post-doctoral Researcher Rich Patrock observed Brazilian phorid flies, Pseudacteon tricuspis , bombarding approximately 30 percent of fire ant mounds they surveyed near experimental release sites in South Texas.

It’s a good question, and there are many technical articles about various insects and the ecology out there. Way above my head!

[Earthling]

*Originally posted by Netbrian *
**What would happen if extincted all the mosquitoes? **

Opinion 1: Nobody knows.
Opinion 2: Bad idea; they’re an important part of the food chain, especially in larval form.

Either way, this article reminds us:

Drastically reducing the number of mosquitos could trigger an increase in the populations of other annoying gnats and biting flies such as no-see-ums and white socks, said Cathy Randall, a pest management specialist with the university program.

So it looks like you’ll just replace one pest for another.

[Sublight]

I was just reading about this question last night. Funny how that works, ain’t it?

In regions of the world where fly breeding-sites are still common, the medical problem continues to be appreciable. But, if flies were removed, say by chemical insecticides, without first addressing the problem of the breeding-sites, the decomposing matter would generate truly unimaginable amounts of bacteria which would infect everything. Flies, although transmitting bacteria, nevertheless keep the situation under control, for their progeny consume the prime source of the germs and remove it entirely from the environment. So, it’s no use removing the flies and leaving the source of infection, for it would make the problem worse. Seen in this light, the fly is not the cause of the problem, but its natural ameliorator.

Murder, Maggots and Men, Dr. Zakaria Erzinclioglu, Thomas Dunne Books, New York, 2000, p.179

So, ignoring possible problems higher up on the food chain, getting rid of the flies without also getting rid of their food source will result in even worse problems.

[Sublight]

I was just reading about this question last night. Funny how that works, ain’t it?

In regions of the world where fly breeding-sites are still common, the medical problem continues to be appreciable. But, if flies were removed, say by chemical insecticides, without first addressing the problem of the breeding-sites, the decomposing matter would generate truly unimaginable amounts of bacteria which would infect everything. Flies, although transmitting bacteria, nevertheless keep the situation under control, for their progeny consume the prime source of the germs and remove it entirely from the environment. So, it’s no use removing the flies and leaving the source of infection, for it would make the problem worse. Seen in this light, the fly is not the cause of the problem, but its natural ameliorator.

Murder, Maggots and Men, Dr. Zakaria Erzinclioglu, Thomas Dunne Books, New York, 2000, p.179

So, ignoring possible problems higher up on the food chain, getting rid of the flies without also getting rid of their food source will result in even worse problems.