House Flies

Within the last week we've had several calls about large populations of flies in residential areas. Seems like a good time to revisit fly habits and control, with an eye to giving homeowners a few helpful hints.

The "house fly" or musca domestica is one of the most common of the thousands of species of flies. When more than the usual number of flies begin to invade a house, control requires some education and a little detective work. Adult flies are pretty easy to kill with over-the-counter bug sprays or an old fashioned swatter. But the problem will not abate until the source of the flies is discovered and removed. Flies can multiply rapidly because of their rapid development time and the large number of eggs produced - several batches of 100-150 per female. Eggs are laid in warm, moist areas, often associated with decaying organic matter such as manure, grass clippings, garbage, damp leaf litter, or decaying fruits or vegetables. They also appear in great numbers when an outdoor pest such as a rodent has died. Eggs hatch into larvae, or maggots. Fly larvae resist light, and typically burrow into the decaying matter from which they hatched. But in cases where flies are abundant and breeding is undisturbed, the maggots may be obvious. In the larval state, these pests are not even slowed down by the liquid chemicals applied for control of other household bugs. Therefore, control of flies is affected by control of the harborage site where flies are breeding. 

The first step in control when flies are invading a house is to check screens and weather stripping on doors and windows. Outdoors, clean up dog feces, rotting fruit, grass clippings, or any other decaying organic matter that may be attracting flies. Homeowners should check garbage cans, cleaning them to remove residual waste. In multiple-unit complexes where dumpsters are used, the dumpster company should be notified if there is fly activity, so a clean replacement can be provided. In both cases, garbage should be bagged before disposal, and cans should be in good repair, with tight-fitting lids. After all these preventive measures have been completed, the residual adult flies can be controlled with fly strips or bug sprays. Again, poor exclusion and/or sanitation are most often the cause of indoor fly problems. Save yourself some frustration by examining the area surrounding your home and eliminating the source of the infestation. For an effective method of killing random flies barehanded, click here. To read an article in Science Daily about how flies react to odors, click here.

Maggots Made Cute

The new animated motion picture, "Fly Me to the Moon" is opening in local theaters today. Press releases for the film give mixed reviews, but we have to give them credit for making even the maggots in this fly-boy movie look cute. However, actual maggots are a far cry from the chubby pink images in the film. They are of course, fly larvae, most often found in garbage areas or congregated around decaying matter. If you have ever encountered these small, off-white worm-like crawlers, you  may already know that most bug sprays won't even slow them down. This is true for larvae in general. To stop them, find and remove the source. Here are some ideas for around the house and yard:

Empty and clean trash receptacles at least weekly. 

Keep doors and windows closed or properly screened.

Use garbage cans with tight-fitting lids, no holes.

Dispose of leftovers in plastic bags, securely tied.

Discard animal droppings as soon as you can, also in plastic bags.

Remove decaying fruit from under trees.

You can call the county department of vector control if  you have large numbers of flies around your property and cannot locate the source. Fly strips are a good way to eliminate adult flies indoors. Since flies can carry diseases like dysentery, cholera, pink eye, and even tuberculosis, it is important to address an infestation in a timely fashion. Unlike the cheerful cartoon creatures in the feature film, flies should not be a welcome guest in your home. 

Mystery Bug Week, Part V: Of Words and Worms

Fly larva
Moth larva

The mystery in this last Mystery Bug Week post is two-fold. The first mystery is more etymology than entomology. We find our customers would rather say they have "bugs" than "roaches," rather have "mice" than "rats," and rather have "worms" than "maggots." No one wants maggots. We can't blame them! In fact, what most people report as "worms" are some kind of larvae. Doesn't that sound better? 

The second mystery is how to tell what kind of larvae they are. In the larval state, most common flying bugs look remarkably similar. There are variations in size, of course, but it is nearly impossible to tell fly larvae (maggots) from moth larvae (see photos above). One simple way to solve the mystery is to take notice of any increase in populations of the adult bug. Have you seen flies or moths buzzing around the house or in the yard? Identifying the adults those worms will turn into is critical in controlling the problem. We have discussed pantry moths in a previous post. They are a stored product pest, so if you consistently see moths in the house the chances are good they are coming from the kitchen or pantry. Find the source, eliminate it, and the problem is solved. House flies are less localized. They could be coming from anywhere - so a bit of detective work is needed to solve the mystery of where they are breeding. Flies need moisture, and usually breed in some kind of decaying matter. Check grass clippings and mulch piles outdoors. Inside, check house plants to see that they are drying out between waterings. Indoors and out, follow your nose. If there is a dead rodent in the wall void or a potato behind the fridge, these would be great sources for breeding flies. Whatever you choose to call the larvae that invade  your home, they are a problem that can be solved with a bit of detective work.

Fly Bye

This helpful tip about the common house fly is not for the squeamish, nor for those with serious infestations. If you have a major fly problem, skip to the next paragraph. If you are squeamish, stop here! This tip is for dealing with random flies that dart through the front door, then circle the kitchen like sharks before landing on your clean kitchen counter - twiddling their legs and daring you to find the fly swatter in time. Approach the fly slowly, with hands about 8 inches apart directly above the resting fly, so that when you clap your hands the moment of impact is about 4 inches ABOVE the fly. Here is where the squeamish will still be looking for that fly swatter. 99% of the time, if you have managed to position your hands correctly without disturbing the fly, you will have a squished fly on your hands as soon as you clap! A little-known fact is that flies lift off vertical to the plane on which they are resting - think helicopter rather than airplane. If you clap above the resting fly, you will inevitably need to wash your hands.

Why not just let the fly live? Because you don't know where he's been! If yours is a typical fly, he may have dined last in manure, decaying matter, or any moist breeding ground for bacteria. He carries that with him, regurgitating saliva and depositing waste on that clean counter - or your bologna sandwich. By comparison, cockroaches are sanitary. If you have a serious fly infestation, here are a few tips for solving your problem. First, locate the source of the infestation. Do you have a trash can with grass clippings that has been sitting too long? A compost pile that is not properly covered or screened? A garbage can with a lid that does not fit properly? Most fly infestations can be relieved simply by drying out or removing the source. While insecticides may not kill maggots in a trash container, boiling water will. And if you find maggots indoors, again the source must be located and removed. Follow your nose, and you may find a rotting potato or a dead rodent that is harboring the flies.