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Pest Control Specialists Contact Us

4012 N. Main Street
Dayton, OH 45405

QUESTION:

You have referenced a couple of times in your various answers of research showing that pesticides only last about 3 weeks or so. Can you provide the source of this research and where such can be found?
Thanks.

ANSWER:

I do get that question a lot, and hopefully I always have had the presence of mind to preface each response with that magical phrase – “it all depends” – because there are no cut and dry answers to the question of how long a pesticide “lasts” once applied. There are too many variables, and these variables include (but are not limited to) – the strength of the concentration applied, the surface it is applied to, the pH of the water or the surface it is applied to, the amount of sunlight or other UV light that hits the treated surface and how long this occurs each day, the moisture level of the treated surface, the level of organic matter in the soil that is treated along with the level of microorganisms in that soil, the heat the sprayed surface is exposed to, and of course the specific pesticide molecule being discussed. Some are more prone to falling apart than others, such as the rapid degradation of pyrethrum once applied. But, even pyrethrum may have an extended life if it is fogged into a dry, dark, coolish wall void as compared with an application into a sunny and warm room.

We end up only be comparing expected lives of pesticides, and one other consideration is that even long after the active ingredient has disintegrated sufficiently that it no longer kills insects, it still may be detectable in the water or soil or on a surface. We speak in terms of the “half life” of chemicals, which is that length of time required for half of the molecules to break down into other things, thus leaving half of the molecules still there until another of those time periods has passed, at which time half of THOSE remaining molecules will be gone, etc. Even though the pesticide active ingredient is still, technically, present on that surface there no longer is enough of it to efficiently kill the intended pest.

For termiticides, if it still is done, we had the standard “ground board” tests done on several specific ground sites in the U.S. The intent was to be able to compare apples with apples so that the effective residual of each termiticide active ingredient could be determined and compared with other active ingredients. For these we heard from product manufacturers that after such-and-such a length of time the product was still effectively killing or repelling subterranean termites, and we heard numbers such as anywhere from 5 years to 20 years or longer. Those were probably the only standardized tests that have been done to determine just how long any particular pesticide molecule remained effective.

However, we do know that certain pesticide molecules are highly resistant to degradation, and these are the inorganic (mineral based) products such as diatomaceous earth, boric acid, and silica gel. We use these in dust products that last for many years, but this is because their effect on insects is much different from that of synthetic molecules and since they are mineral they simply do not break down, any more than we would expect a chunk of granite to stop being granite in a few years. Boric acid is used in baits, as it must be ingested by the bug to be toxic, and even long after the bait is no longer palatable it still would be toxic if ingested.

A few years ago at an educational conference one of our respected industry researchers spoke, and I don’t even remember what the primary topic was, but the talk got around to how long insecticides lasted for insect control. His comment was that he would be surprised (speaking about synthetic pyrethroids) if ANY of them lasted more than two weeks. Again, depending on the circumstances this could be far shorter or far longer. We can come up with formulations such as microencapsulated products where the active ingredient is protected from all those environmental hazards, and now perhaps the effective residual is a month or more. One manufacturer claims their pyrethroid granules will last for 3 months, but maybe that granule is hidden under foliage on a relatively dry soil. Put that same granule out in the sun on hot concrete and maybe it’s less than a week.

So, there really is no good source that is willing to commit to hard and fast numbers. The chlordane that may have provided 40 years of termite control under the slab of a home would probably disappear in just a few days when applied to a hot asphalt driveway. The permethrin sprayed under the eaves for spider control is going to last longer than the same material applied to alkaline soil in the sun along the base of the house.

Now, didn’t I do a great job of dancing around a direct answer?

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QUESTION:

How can we get rid of fruit flies or gnats in a home and what chemical can I use?

ANSWER:

There are a great many insecticides labeled for use on vinegar flies and other miscellaneous small flying gnats. However, all of these chemicals need to be set aside for the moment and a few other steps taken first if the control is going to be successful. There is no doubt that any insecticide will kill any adult fly, but fogging or spraying surfaces for fly management does not get to the real problem, which is that somewhere in this home there is some unsanitary situation that is supporting these flies, and until that “contributing” condition is found and repaired you would continue to have the production of adult flies.

Fly control must begin, as does pretty much all pest management, with Identification. If you do not know exactly who your adversary is you cannot know about its biology and likely breeding habitats. “Gnats” could refer to fungus gnats, midges, phorid flies, drain flies, or vinegar flies, and each of these could have a very different breeding resource. Fungus gnats often breed in wet soils, and indoor potted plants become wonderful places for them to breed. Drain flies love the buildup of crud in sink and floor drains, and these must be discovered and cleaned, and then KEPT clean so that the breeding does not continue in the future. Vinegar flies go for anything that is fermenting, and this time of year there can be a lot of outdoor resources for them as vegetable gardens and fruit trees are abandoned and the tomatoes and apples hit the ground and begin to rot. This then could result in a lot of these flies finding their way indoors, so exterior cleanup may be important too. On the inside it could be damaged or old fruits and veggies on the counters, old soda or beer bottles with liquid still inside them, or in the case of the Dark-eyed fruit fly even more possibilities. This species and Phorid flies can breed in all the same places that either vinegar flies or drain flies will breed, so determining just what kind of fly or gnat you have is important, and then inspecting to find the breeding sources Step 2.

This really does offer an opportunity to professional pest control companies. You provide the expertise to your customers of knowing how to identify the pest, how to search for the SOURCE of that pest, and how to eliminate the problem at its source. For drain, phorid, and fungus gnats this might lead to a monthly application of drain cleaning products to every drain in the home, and for a nominal fee that is reasonable to the customer but profitable to you. Most of the drain cleaning products now are either enzyme or bacteria based, and are considered non-toxic to people and pets.
Sometimes you may look at the presence of these persistent little flies as a signal that something inside the structure has a problem. Commonly phorid flies breed by the thousands in the soil under a slab where pipes have broken, allowing gray water or sewage to flow under the slab. Fungus gnats may indicate some excessive moisture condition inside walls or under sinks. And vinegar flies are telling us that something is rotting or fermenting that should have been disposed of. Once you are able to locate the source of the problem – that place where the larvae of these flies are developing – it can be corrected and the breeding source eliminated. At that point you may find a need to lightly fog the rooms with pyrethrum to kill off lingering adult flies, but to rely on pesticides initially for fly management is likely to have disappointing results.

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QUESTION:

People are talking about fogging for Bed Bugs and applying a residual application to exterior surfaces around baseboards and wood work. My opinion is that there is no substitute for thoroughness and that fogging would probably not reach harboring bed bugs hidden deep inside voids, and that the majority of chemical treatment needs to be applied in areas that the bugs harbor, providing longer exposure time to the products. What is your recommended treatment for bed bug infestation?

ANSWER:

I agree with you completely Stephen, and suspect that a lot of technicians are going to shake their heads and say that I am out of my mind. But, given what we currently know about bed bugs and their susceptibility to our current insecticides we recognize the need to ensure the longest possible exposure to the active ingredients. Applying the products to open, exposed surfaces either by fogging or by “baseboard” spraying and expecting the bed bugs to linger on those exposed surfaces long enough to absorb a lethal dose of the active ingredient is, in my opinion, danged optimistic. We learned this a LONG time ago with German cockroach control, that these fast moving insects just ran over the narrow swath of active ingredient sprayed along baseboards and had no chance of picking up enough a.i. to kill them. Applying the insecticide directly into their harborage points was the best method of control. Ironically, this also placed that active ingredient out of reach of humans and pets that might live or work in that area, and this still needs to be a consideration with bed bug control too.

The Common Bed Bug is primarily a nocturnal creature, and therefore spends all of those daylight (or artificial light) hours hidden in some crevice, hole, or void. It just makes good sense that this is where we should apply our poisons (yes, I know, I said that word) to have the best and longest contact with them. Some studies by one of our most respected bed bug researchers recently concluded that for many of our commonly used insecticides it took many hours of contact with the active ingredient to kill bed bugs, often not even killing 100% of them. You might enhance this with the use of dusts or microencapsulated formulations, where the particles containing the active ingredient are more likely to cling to the exoskeleton of the passing bug, but even with these the best application is to place the product directly into the harborage points where the bugs will spend perhaps 20+ hours of the day. Since a bed bug feeds for no more than 10 minutes it seems logical that it comes out of hiding, locates the blood source, feeds, and then goes back into hiding. These are fairly fast-moving insects, so they do not linger on exposed surfaces any longer than they have to.

Perhaps the fogging / surface spraying concept is related to a desire to keep the price down by doing the work as fast as possible. Perhaps there is a misunderstanding about the capability of a fog to penetrate into voids of any kind, which it will not. Perhaps there is still a belief out there that The Common Bed Bug can be attacked in the same manner you might treat for earwigs or crickets, which you cannot. As our experts have told us many times, the bed bug cannot be successfully treated in the same manner as ANY other structural pest, and to do so is to be doomed to failure. I personally think that fogging has no place in bed bug control (again, I recognize that there will be serious disagreement). The pyrethrum DOES seem to enhance the effectiveness of the insecticides used, but it should be mixed with the residual active ingredient and applied as the crack and crevice treatment. Granted, it takes longer to properly treat every crack, crevice, and void in an infested room, but this is going to be the best way of knowing that all the bed bugs are going to be exposed to the active ingredient for the longest period of time, which currently seems to be needed.

Further, if we listen to our industry’s best experts in this area, total reliance on insecticides to eliminate bed bugs is also not the best policy. These are tenacious animals, and defeating them down to the very last nymph and egg is best done with many non-chemical tools and techniques as well. These include the installation of mattress / boxspring / pillow / sofa encasements, steam along mattress seams or carpet edges, heat with laundering, dryers, or heat chambers, monitors and traps to determine the succes of the program.

And, I really have to include the vital need for PROPER IDENTIFICATION. I have seen many other kinds of bugs identified improperly as The Common Bed Bug, including carpet beetles and crab lice. I also recently identified for a PMP some BAT bugs that were in a home, and these would be treated very differently from The Common Bed Bug. Without proper ID we are likely to go off on the wrong path, and this is not helping our customers or our reputations.

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QUESTION:

I would like to know what is the best way to eliminate carpenter ants inside in the winter, or can you? Thank you.

ANSWER:

Ants are tough adversaries no matter what kind and when and where they occur. Pity poor Florida, as this state seems to be the testing ground for every new pest that enters North America, and they are still dealing with the recently introduced Crazy Ants. Carpenter ants come into structures for a couple of reasons – in warm weather they look for drier places to be for their late stage larvae and their pupae, so they may relocate to voids within structures and bring these offspring with them. They also may relocate to drier places once winter weather hits. Since the ant colony does not really go dormant, although in cold climates the activity really slows down, they need to survive harsh weather. One of our top industry experts on carpenter ants states that nearly all of the time you find these structural colonies they will be “satellite” or secondary colonies that still are part of a primary or parent colony that is most likely outdoors within some wood. This commonly will be old root systems or buried wood in the soil, but could be a rotting log or tree trunk, landscape timbers, etc.

Now, once the really nasty weather hits there probably is not going to be much travel between the structural colony and the parent colony, and there also is always that chance that the colony in the home is NOT part of another colony. But, the adult insects are still active inside and probably getting pretty darned hungry, since they tend to live off fat stores in their bodies through the winter months. Outside there is not going to be anything for them to eat – honeydew, other insects – but inside they may continue to forage. So, baits could be one excellent option for indoor winter ants. Carpenter ants seem to readily take granular baits, and these could be placed within wall voids or other places where the ants will find them but occupants won’t.

Carpenter ants are nocturnal, so if they do come out inside to forage it probably is at night, limiting the times the homeowners may see them, but knowing where they are trailing will be useful in control. You could use a non-repellent that has a good transfer effect along trail routes indoors, and sometimes even a microencapsulated product works well because the particles stick to the ants. Locating the exact location of the indoor nest is ideal, because this allows you to find a way to inject insecticide directly into that nest, whether it be an existing void like a wall void or a space under some attic insulation, or a cavity the ants themselves have created. If they are excavating the wood they should be pushing out the debris, so ask the homeowners if and where they are finding any little accumulations of sawdust or bits of insects or other debris of unknown origin. Directly above that point should be where the ants are located. You may have to drill through a wall, but could do so discreetly, and then inject dust or aerosol into that cavity inside, or use a void injector fogger to fog a residual insecticide into the nest.

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QUESTION:

I need fly lights for a subway that is connected to a liquor store. It’s all open to go into either one and there are two entrances, one for the subway and one for the store. Do I need a fly light over each door opening and one inside the subway? If so what kind of fly lights should I use?

ANSWER:

One of the failings with fly control is the use of too FEW control devices, and the problem with flies is that they can continue to be annoying until they finally “see” the control device and stumble into it. So, this brings up a couple of thoughts. The first is that the expectations of the customer need to be realistic, and if they believe that you will eliminate all of the pesky flies by installing a fly trap they will be sadly disappointed, and upset with you for failing to meet their expectations. It would be appropriate to perform a careful inspection of this facility to determine what kinds of flies these are and how they are getting in. This inspection may also reveal some possible breeding sites that could be eliminated or food attractions that do not need to be there, and cleaning these up (the Sanitation part of IPM for flies) may help to reduce the problem. By identifying the flies you get the best idea of possible breeding sources. For example, if these are blow flies then perhaps there are some animal carcasses tucked away nearby after rodent control baiting, or really filthy garbage cans or dumpsters that can be properly maintained. Similarly you might get hints on breeding sources if they are phorid flies, drain flies, or fruit flies.

Another problem here is that I am not completely certain of what you mean by “subway”, but since you are in California I am going to go with the likelihood that you mean a Subway sandwich shop rather than an underground train station. With that in mind you need to install enough fly traps of the proper size and kind to fit the needs of this area. The traps need to be placed in the most effective locations to attract and capture flies as quickly as possible. House flies tend to fly in a zone between 1 and 6 feet off the floor, and placing traps in this zone gives the highest likelihood the flies will see the traps quickly. Placing the traps up near the ceiling and behind a plant (you know, so customers don’t see them and think there is a fly problem) also hides the traps from the flies. It is important that the flies see the UV light as quickly as possible. Fortunately Univar carries a really wide variety of UV light traps, many of which are quite aesthetic, and look more like decorative lighting than a bug control device.

UV light does not shine around corners, so you need to install enough traps to make them visible to flies in any of the infested rooms. Depending on the size of the trap you may need to install more than one in a large room, as the UV attraction diminishes with distance, and even though you and I may be able to see the light from 35 feet away, the attraction to the fly will be much less as the distance increases. UV light is not a vacuum cleaner, and flies that enter a facility will not instantly veer off to investigate the light. Instead, they enter at that low height off the floor and begin flying here and there to find the source of food odors. Installing a UV trap right at the entrance so that flies can see it when they come in would be a good first defense. If the entrances to these two shops go to the outdoors then it is more difficult to prevent them from getting to the shops themselves. This is the value of inspecting the exterior as well to see what sanitation issues might exist that are attracting flies to the area.

There are fly “zappers” and UV fly “traps”, and the traps are more appropriate for indoor use. They capture and contain the flies on the glue pads and they do so silently, so no one hears popping and sizzling sounds as flies hit an electric grid. Fly traps also can be placed anywhere with respect to food, but placing them right on a food counter may actually bring flies to that point, so offset a bit is better. I would suggest at least the two traps, one near the entry door and another near the food preparation areas. But, if there is a separate kitchen where these first two lights would not be visible then a third or fourth trap may be needed. The UV bulbs are good for about 1 year of constant use, at which point the UV emission decreases enough that they should be repalced. Univar can help you with the recycling of these tubes.

Again, there are so many different choices with UV light traps, and we carry traps from a dozen different vendors, that I hate to recommend any one kind. On PestWeb you can go into the Product Catalog and under Equipment / Insect Traps / Light Traps view a list of all the traps we carry. On EZ-Order you can view images of each kind and make a selection based on the appearance and size. You also can discuss the choices with your Customer Service Rep in the local Univar office.

View past Ask Mr. Pest Control questions.

QUESTION:

Several weeks ago in southern California I captured a very large flea in front of an apartment complex. It was noticably larger than a cat flea, lacking the prominent genal comb, and had rather large eyes. I have had no luck at the I.D. To make it worse I had placed it in a small collecting jar which completely dried it out in my hot vehicle that day. Any hints on what it could be would be greatly appreciated. Thanks, your knowledge of this field has been greatly motivational to me.

ANSWER:

Thank you for the compliment Shawn, and I agree that correct identification can often be extremely important, even with insects that would seem as cut and dry as fleas. The vast majority of the time the fleas we encounter in urban pest management will be Cat Fleas – Ctenocephalides felis – regardless of whether they are on dogs or cats. This just happens to be the common pet flea in North America, and also can be a common flea on wild animals such as raccoons and opossum. But, other kinds of fleas exist around homes, and if they happen to be associated with wild rodents the normal control procedures that would resolve most flea problems just might not work.

I had a friend give me a few specimens of the Mountain Beaver Flea that he collected from beaver dens during some field work he was doing, and these giants may be nearly 1/3 of an inch long, so fleas are capable of some large sizes. Of course, it’s pretty unlikely that you stumbled upon some beaver fleas in front of an apartment in the Los Angeles area, so that was just for fun. Your observation that the “genal” comb was not present was a good one, and a reminder to us that identification of fleas relies on examining them under high magnification so we can observe some small characteristics. One of the most important is the presence or absence of these “combs”, which are rows of spines along either the bottom of the head (genal comb) or at the back edge of the pronotum (pronotal comb). The genal combs look like a long row of teeth sticking down, and this one is present on the common cat flea, as well as on the dog flea, mouse flea, and rabbit flea.

The genal comb is absent on most of the other rodent fleas (Oriental rat, squirrel, northern rat, ground squirrel, as well as on the rare “Human” flea. You don’t mention whether or not the rear comb, the pronotal comb, was present or absent, and this does separate these rodent fleas. From the basic pictorial key I have available the fleas with the largest eyes in relation to their head are still the cat flea and dog flea. Even dried out the exoskeleton of the fleas tends to stay firm enough that you can still observe the important characters for ID. What tends to dry out and shrink is the abdomen, and that is less important. Sometimes a fully grown or fully engorged female Cat flea can look “huge” in comparison with others, but since that genal comb was missing it could not be a Cat flea.

A 1943 publication called “The Fleas of California” listed 200 different species and subspecies of “western” fleas, so there are plenty of other kinds around that we could come across. Even at that time 127 of the species were confirmed from California from such diverse host mammals as gophers, bats, foxes, rabbits, moles, shrews, and of course a great many different kinds of rodents. Unfortunately this short publication did not go into details on the identification of different kinds, so we cannot provide you with the definite ID. It might be of interest for you to take this to your county department of agriculture for identification. You never know when something new and important may show up for the first time, as the recent discovery of the Asian Tiger Mosquito in southern California proves to us. And, your eyes in the field are a huge help to the state agencies in discovering these kinds of pests.

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QUESTION:

We have a well kept house that we service every two months and the only problem they have is springtails, which I sent off to Mississippi State for proper ID. The only place they have seen them is at the sink and at the back door. I have found no water leaks. The outside has flower beds around the house and no sprinklers in the yard. Any suggestions on what to do?

ANSWER:

Springtails can be one of those very frustrating insect problems. We know that they must be associated with moisture somewhere because they feed on things that grow in damp situations – fungus, mildew, algae, and decaying plant materials. They can be extremely common outdoors in damp landscape, under boards, under potted plants on the patio, under thick layers of leaf litter, mulch, or groundcover. But, it always is dampness that attracts them and indoors they can breed in wet situations. Unfortunately those damp conditions often can be hidden, and the presence of springtails could be telling us that some excessive moisture problem exists someplace that should be located and corrected.

Often it may just be potted plants, and in bathrooms this may be the reason you find them in the sink or bathtub. The springtails are attracted to the wet, rich soil in the pots, breed there and produce more of themselves, and then hop out to wander around on the sink counter, getting trapped in the sink itself by the smooth porcelain. Investigate this possibility in your account, and even move any potted plants outside for awhile to see if the springtails cease to occur. It could be a moisture problem in a crawlspace if one exists, or even under a slab where cracks or gaps allow the springtails to move up into the living areas.

The fact that one of the locations you are seeing them in is at the back door could suggest that these are originating out in that back yard, and perhaps cooling weather or recent rains caused them to move around more and even head into the structure looking for a better location to survive the oncoming winter weather. Sometimes hot, dry weather does the same thing, causing the moisture-loving insects to leave their now dry habitats and move into or under structures. You might place some glue traps around the OUTside along the foundation on either side of this door, and check in a week to see if any numbers of springtails are on the traps. Of course, make certain no other animals can get stuck on the glue, perhaps by placing the traps under something or within a trap station.

Do inspect carefully under all sinks to see if any leaking or sweating pipes are creating damp areas that may grow mildew. Inspect under the refrigerator to check for any moisture problems. If there is a basement check it for wet areas, especially around water heaters. Moisture always is the key for where they are coming from, but they may end up in dry locations that mislead you.

And, while we are on the subject of springtails I have to mention another side topic. The internet is filled with websites that talk about “Collembola Mites” and how these nearly invisible parasites will bite people and burrow into their skin. This is completely, absolutely false, and these kinds of websites are there only to justify the imagined problems that many people have where they are convinced something is eating them. First of all, mites are mites and Collembola are springtails, and as far as knowledgeable entomologists know the two Orders of arthropods have not morphed together to become some new creature. Second, springtails have no ability to “bite” or burrow into skin. These kinds of claims should patiently be countered with accurate information from ethical university websites.

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QUESTION:

I live in Phoenix, AZ and I am just starting my own company. I have been offered a job to do general pest control around Phoenix water treatment plants where there is ground water and potable water and I wanted to know a safe product to use in that situation.

ANSWER:

I think this is a situation that absolutely demands IPM, and the insecticides should not even take the forefront in your approach. Obviously you are dealing with a sensitive site that could have serious consequences if you somehow managed to get any kind of pesticide into the drinking water for a city. The reality may be that ground water is not a major concern, since nearly all of our synthetic and natural insecticides have very low water solubility, and therefore have little likelihood of moving down through the soil to enter underground water aquifers. Certainly, though, any runoff of pesticides from treated sites or dust blown off treated soils and into drinking water might be a concern, and given that pesticides can be detected at extremely low concentrations these days (in parts per trillion) someone really looking for these molecules in the water could stand a chance of finding them if you are careless.

I don’t know exactly what pest problems would occur around a water treatment plant, other than the usual assortment of crawling pests. But, I think it would be important for you to put in writing exactly what pests you have discovered there with your inspection and exactly what contributing conditions you have found that are encouraging these pests to be in this location. You then can outline the steps needed to correct those contributing conditions, such as physical changes to the landscape, better storage practices for things that may be stored outside, sanitation to remove unnecessary rubbish or plant materials, exclusion to prevent bugs from entering the facilities. Every step you can make in these areas means less insecticide usage and longer relief from the pests.

Since contamination of the water is the principal concern you should look at products and application methods that would prevent any possibility of the products entering the water. One of these would be the use of bait products, and these could be placed within bait stations where only the pest animals would have access to them. Again, it all depends on what the pests are as to whether or not baits are useful, but you can determine that. Another preventive method is to avoid any treatments that may enter the air, so fogging is out and perhaps even power spraying should be avoided. If you need to “spray” you can use a backpack or hand sprayer to control the mist and to direct the application only into pest harborage points. These may be cracks and crevices, voids, under objects on the ground, etc.

I don’t know that any “pesticide” would be considered 100% “safe”, and of course we avoid the use of the “S” word anyhow. Some groups of insecticides may be more suspicious than others, such as the pyrethroids that currently are taking hits in the political arena with respect to potential contamination of waterways. You may want to stick with products that have very short residuals, such as many of the plant-derived insecticides. Not only might these be more acceptable to this kind of customer, but their rapid degradation once applied means less chance of their finding a way into the water. Granular formulations, applied carefully and only to selected sites, might be good choices to prevent the chance of runoff or drift into water.

If there are any pigeons or other pest birds hanging around these facilities this also gives you a great opportunity to offer bird exclusion and management. There have been some highly publicized incidents in my area where local water supplies were contaminated with bird feces, and the facilities had to shut down to correct the health problem.

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QUESTION:

What is the best plan of action for a large retail store that has a small food service in the front of store with a bad fruit fly problem? In another setting fruit flies are getting bad in a coffee location where some food is served along with a seating area for people to eat and drink coffee. What sources could you suggest that would tend to be sanitation issues.


ANSWER:

Fruit flies, also called vinegar or pomace flies, tend to occur close to where breeding sources are available, although it’s not beyond the realm of possibility that they may be coming in from outdoors. This seems especially to be the case in late summer and early fall when we have those “Indian Summer” days of warmth and moisture. A lot of home gardens and fruit trees are losing their crop to fall to the ground, creating an abundance of opportunities for the flies. But, we should assume that your situations must have some attraction and possibly breeding source available. Anything sugary and fermenting is the draw for vinegar flies, so in food service areas this commonly will be the soda dispensing machines. There may be spills under and around the equipment itself, but it is important to be able to open the machine and take a good inspection inside. Leaking tubes can dribble soda syrup onto the interior, and this can breed a lot of flies.

The adult flies may be attracted to the dispensing nozzles themselves, so cleanliness is important here. Inspect the floor all around the areas where the employees make and serve the food, as spills tend to accumulate and get kicked under the counters where they may not be removed with regular cleaning. The cleaning, even if it is done daily or some other regular interval, may tend not to be very thorough, so debris gets pushed into crevices along walls and under equipment and left there. A crack against the wall with even a slight amount of food debris can breed large numbers of these tiny flies. Look for discarded food containers that are lying unnoticed under counters. If there is a salad bar it needs to be inspected carefully, including underneath where spills may accumulate. Check items like mops to see if they are cleaned and allowed to dry properly, as a wet mop with food debris in it serves as a major attraction and breeding source. Check all drains to be sure they are not filled with organic sludge buildup, as drain flies or the phorid flies that resemble fruit flies breed easily in these areas.

In a facility that serves coffee there could also be some of these other fly resources, such as spilled sugary foods, but so many coffee service facilities serve the wide variety of sugary drinks now too that spills of these materials could attract or sustain fruit flies. It takes a good flashlight and knee pads and patience to make that very detailed inspection in all of the hidden places to find the source of the problem, but this is necessary if eliminating the flies is to be done. One perfect example was a heavy vinegar fly problem that was finally traced to several beer bottles with lime wedges in them that had been kicked under a counter in a bar. Inspect the waste stream in these accounts to ensure that garbage containers are properly maintained – washed daily, plastic bags in place and emptied daily. Inspect the refrigerators to see if there is any buildup of water under them, along with the normal accumulation of debris that seems to end up under large, heavy appliances.

It would be helpful to use some of the fruit fly traps in these accounts. These use only attractants such as vinegar to draw the flies into the trap to drown, but they can help you to pinpoint just where the source may be. UV light traps will capture a lot of the adult flies, but of course do nothing to resolve the source of the problem. Applications of labeled residual insecticides also can kill a lot of resting adult flies, but again do not get to the heart of the problem, which is wherever there is some spill or discarded food that the larvae are breeding in.

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QUESTION:

Regarding Termidor WG, how long does it take for it to bond to the dirt? For example, if you finish a termite job and then it rains heavily for about two or three hours. In this case the house is on level ground and the soil did not wash away.

ANSWER:

The active ingredient in Termidor is fipronil, and fipronil is known to have a very LOW water solubility. This means that the active ingredient itself does not readily dissolve in water and therefore is not carried away by water by itself. This is extremely important with respect to ground water and the ability for a pesticide to leach down through the soil and into the underground aquifer. Chemicals that are HIGH in water solubility can therefore dissolve in water in high concentrations and higher amounts of that chemical can then move with water down through the soil profile and into underground water. Fipronil tends not to do this, and very little of it will be carried in water.

We use water only to dilute the insecticide formulation. The fipronil within your spray solution is not dissolved in the water, but only suspended, and with a WG (water dispersible granule) the particles of the dissolving granules themselves, with the fipronil mixed within that particle, also simply suspend in the water mixture. Once we apply this spray solution to soil the fipronil has a strong affinity for the soil particles, and the molecules of fipronil attach readily and stay put very well. Exactly how long this takes would be very hard to say, but the best practice would be to apply your termiticide spray only when it will be allowed to dry in the soil. The Termidor 80 WG label states that we cannot apply the material “while precipitation is occurring”, but I believe to be on the safer side we also should not apply it when rain is imminent. If you saturate the soil with your spray application and then heavy rains come on top of this it greatly increases the chances that runoff of the soil could occur. This is the real danger of movement of the fipronil.

In your instance you know that the soil did not wash away from the treated areas, so I believe you are fine. If the soil is still very wet from your application there could be fipronil still in suspension in the water, and then heavy water on top of this could move that fipronil further into the soil, but somehow I doubt that ground water contamination is an issue in this case. What you may have happen is that the fipronil concentration in the soil could have been diluted quite a bit by moving further down with the rain, but hopefully it still exists at a concentration effective on the termites that encounter it later.

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