Archive for the ‘Pest Questions’ Category

Mar 1, 2012 – Little Troubles

QUESTION:

Small ants with small wings appear every spring in a kitchen. What could they be and what is the best thing to use to eliminate them permanently? There is a concrete slab throughout the home.

ANSWER:

I can think of three possibilities, and if these are dark black and shiny ants then they probably are just called The Little Black Ant – Monomorium minimum. If they are very light colored, sort of orange, they they are either Pharaoh or Thief ants, and these two species are nearly identical in appearance. Sometimes Pharaoh ants will have a bit of black on their abdomen as well, but the best character to separate them with accuracy will be on their antenna, and obviously you are going to need to use good magnification to see this. I have a 20X hand lens that does magnify sufficiently, but the best tool every pest control company ought to have in the office is a dissecting microscope. This will enable you to magnify the tiniest of bugs perhaps 100X or so, and now you can be certain of what the pest is. 

At the end of an ant’s antenna there will be several enlarged segments that we refer to as the “club”. On a Pharaoh Ant it is the last three antennal segments that are enlarged while on the Thief Ant it is only the last two segments. This is an important distinction to make. Thief ant colonies are generally very small and found in small hidden places. Pharaoh ants can have colonies of hundreds of thousands of workers, and they often split off and establish new colonies, so you may have a number of separate colonies within a single structure and all of them need to be dealt with. Pharaoh ants also are very sensitive to insecticides, and if you rely on chemical sprays it could be the  trigger that separates workers from their home colony, and since all the workers are females some of them may begin their own colonies in new places. 
Baiting is an excellent method for doing control of Pharaoh ants, although now we also have a number of “non-repellent” insecticides that can be used along with the baiting. The best program probably combines the two. Liquid or gel sugar baits work well on the tiny ants, and it is best to figure out which nourishment they are looking for – carbohydrate or protein – and offer the bait that they are most likely to accept. You need to find out where their foraging trails are and place the baits as close as possible to these ants, but in a location that is acceptable to the customer as well. Use several different kinds of baits, as this may offer the best chance the ants will accept it. If you can get them really interested in a toxic bait this may be the best chance for eliminating all of the colony, as the foragers take the bait back into the colony and pass it around.
Pharaoh ants, and obviously I am guessing this is what you may have, also may have dozens of egg  laying queens, so it’s even more important to impact the colony itself. If it is Thief ants your inspection may discover the actual colony so you can treat it directly. Their colonies may be only a few hundred ants. Since you feel you are seeing these ants only in the Spring it’s also possible they are outdoor colonies that are foraging inside the structure, and in this case the application of a non-repellent contact insecticide around the perimeter of the outside foundation may be very helpful. Use a product like Termidor that you know offers a good Transfer Effect, and this will help to eliminate that outdoor colony as well. 

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Pest QuestionsMarch 01, 2012

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Feb 27, 2012 – Rodent Station Intervals

QUESTION:

How many feet apart should you place LP rodent stations?

ANSWER:

This is a good question, and there really are two separate answers. The unfortunate answer, but one that is necessary, is that you may be at the mercy of an in-house inspector for some commercial accounts, such as a food warehouse with an on-site auditor or inspector who has his or her own guidelines on this. I will avoid naming names because there probably are several different agencies that do this, but some PMP’s run into difficulties trying to convince the on-site inspector that he is requiring something that is not necessary. The industry “standard” for so many years has been that we should locate stations for rats every 20 feet and for mice every 10 feet, on the basis that rats or mice may not travel any further than these distances for their food resources. 

At a seminar a few years ago Dr. Bobby Corrigan addressed this and stated that this standard was based entirely on USDA recommendations back in the 1940’s, and that there was no science behind that standard. It was just stated and our industry followed it without knowing why. What Dr. Corrigan now promotes is that there is NO set distance apart for rodent stations, and that you must evaluate each and every situation to determine how many stations are needed. There is no “cookie cutter” approach to this. However, if some outside agency and inspector are on site and demanding that you follow their guidelines, no matter how outdated, then you are obligated to do as they wish. 
Your initial and ongoing inspections of the account and facility will tell you what the level of the infestation is, and where the rodents are finding food, water, and harborage resources. You can base your knowledge on signs such as an abundance of droppings in some areas versus no signs of activity in others, telling you to concentrate your stations where you see the activity. You may find obvious harborage in some areas and put larger numbers of stations around that point in the hope of intercepting rodents as they move out to forage. You may end up with some stations for rats just 5-10 feet apart and others spaced 50 feet apart, depending on the need. 

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Pest QuestionsFebruary 29, 2012

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Feb 28, 2012 – Hatched And Hungry

QUESTION:

In regards to a newly hatched bedbug nymph, how soon does it need to have its first blood meal to remain viable.

ANSWER:

It seems pretty clear that we are not going to starve bed bugs out of infested homes. Typically we read that a newly emerged bed bug nymph must feed within just a few days or it will die, and this may be the “normal” situation for most of these newly hatched bugs. But, in the excellent “Bed Bug Handbook” by Pinto, Cooper, and Kraft, they report that one of the authors “has had newly emerged nymphs survive for over three months without a blood meal”. This tells us that at least some of the first instar nymphs are likely to survive for a long time, and all it takes is just those few survivors to get the problem rolling again. This is the reason that our industry experts advise us that we must kill every last bug and egg to be able to claim success. To leave just a couple of live eggs behind means the problem is still there. 

Older nymphs and adult bed bugs can go a lot longer without a blood meal, and since blood is the only thing they eat the presence of a host animal is necessary. Just how long they can survive depends a lot on temperature, and at 50 degrees Fahrenheit a bug that has had a previous blood meal may survive 5 to 10 times longer than it would if the temperature is 80 degrees. A table in the bed bug book is fascinating but frightening, showing that late stage nymphs that have previously taken blood were able to survive for up to 485 days without another meal. That is well over a year with the temperature at 50 degrees, although it dropped to only 40 days at 80 degrees. Adult bed bugs were not far behind, averaging about 415 days (50 degrees) and up to 87 days at 80 degrees for females. Obviously numbers like these are not hard and fast rules, but they do point out the survival mechanism built into these efficient parasites. 

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Pest QuestionsFebruary 28, 2012

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Feb 25, 2012 – Proper Pesticide Transport

QUESTION:

I see pest control companies that use cars as their service vehicles, and I believe they transport the chemicals inside the passenger compartment in a locked box. Is this
legal?

ANSWER:

This is a matter of interpretation, and the ones to make that interpretation will generally be the county regulatory agency that oversees pest control company activities. Since you are in California I can speak from a bit more experience on this. 

I would say that in nearly all cases the use of a passenger car would make it illegal to have ANY kind of pesticide inside the car, other than in the trunk. The wording of the law is that all pesticides must be transported in a compartment “separate from” the driver’s compartment. Many companies use vans, and if they have built in partitions of some kind that clearly separate the driver from the storage areas then this may be okay with regulatory inspectors. However, carrying rodent baits in a cardboard box or a hand sprayer with chemical mixed up in it would not be considered compartments “separate from” the driver. Even a plastic rodent bait disc is a pesticide, and it must be stored for transport in some separate compartment. 
So, it is one of those somewhat vague regulations that is open to interpretation, unfortunately, but any county’s inspectors may approve or disapprove of it. Obviously a consistent interpretation would be easier on us, but sometimes allowing things like this can be helpful. As a supplier of pesticides I believe that Univar has taken the stance that even the trunk of a passenger vehicle is NOT separate from the driver’s compartment, and we will not release pesticides to people who come to our will call counters in their cars. Clearly air movement easily flows from the trunk into the seating area of that car, and thus any spill of chemical in the trunk could jeopardize the health of the driver or passengers. Just putting a locked box inside the car and claiming that this constitutes a separate compartment is a bit of a stretch, but do check with your own local inspectors and get their opinion on it. 

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Pest QuestionsFebruary 27, 2012

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Feb 26, 2012 – Chemical Questions

QUESTION:

Do you believe the only way to avoid more than a mild presence of liquid pesticide ‘junk’ around a cap is by allowing the product to drip for 20-30 seconds? Do you think making a concerted effort to not get liquid around the outside threads of the cap area is the only way? A related question pertains to the little flakes and chips of pesticide that sometimes do not break down in a tank mix. I have assumed these are generally pieces that stuck to the threads around the cap, and through twisting the cap have flaked off and perhaps landed in a tank mix. I really think I am one of the most careful professionals concerning chemical contamination. Are those chips considered as dangerous as the liquid form? I have had small chips get stuck in filters and I really do not know what to consider them (regular trash or active concentrate). Many of them are not soluble through regular tank mix agitation. What is your opinion, and do other technicians sometimes have a problem with that flaking of product that has accumulated around the cap area?

ANSWER:

Well, I’ve never really given much thought to this before Christopher, so we’ll see where my mind wanders. I suppose it would be normal for trace amounts of liquid to remain around the outside of the threads when you pour the material and then replace the cap. The likely result then would be for diluents to evaporate and leave behind the more pure active ingredient, and this very well could be the flakes that you notice. If so then these flakes could later end up in the tank and be difficult to dissolve back into solution, thus leading to your second observation. And then if these more solid flakes are taken up into the pump they would be filtered out before getting into the narrow passageways in the spray nozzle. 

So, obviously all I have done so far is recap what you already told me, but your question seems to center on whether or not these little flakes are of any concern to you health-wise. If they do concern you perhaps you can have a dedicated rag available to wipe the threads following each use of the material so that no buildup occurs. Now perhaps the question arises of what to do with that rag that obviously is “contaminated” with pesticide. Well, I suppose you could toss it in the laundry along with your “contaminated” clothing. Or, you could do as you now do with a lot of other equipment that has trace amounts of pesticide on it and just dispose of it in the garbage as you would empty aerosol cans. This has always been an interesting question. How do you dispose of old spray hose, or old shoes, etc? How do you legally wash your service vehicle, knowing that you are washing pesticide off of it and onto the surface below? The answer is that so little actual pesticide is involved that it really can be overlooked, as long as the materials are ending up in a landfill somewhere. 
Similarly, when you open the filter you could knock loose most of the material on it and then dispose of the paper or rags with that debris. Even if they are active ingredient the amount is going to be insignificant once it all reaches a landfill. It would seem to be inevitable that we will create some level of pollution, but it still can be dealt with in a responsible manner that does not ultimately pose any danger to our environment. We triple rinse containers that held liquid and pour that rinsate into the tank for further use (and this may also then wash some of the dried flakes in as well). But, we do not triple rinse bags that held granules or dust, so legally disposing of these containers in a sanitary landfill will inevitably carry some of the residual pesticide with it. 
I don’t look at any of this as bad environmental stewardship. If we use the products properly we end up with very little wasted material, and since insecticides in particular degrade fairly quickly once exposed to the conditions of the environment – UV light, water, heat, soil micro-organisms – those trace amounts in the landfill are not going to be there for long. 

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Pest QuestionsFebruary 26, 2012

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Feb 23, 2012 – Happy Where They Are

QUESTION:

I service a potato processing plant where one of their shops has 2 pigeons roosting in it.
From what the customer has said they have been there for over 2 years, but in the 4 months
I have been working on site I have only ever seen the same 2 birds. Exclusion is as good as
it will get and I can’t seem to catch or bait these 2 pigeons. Any suggestions? I have prebaited with several different styles of feed, none of which has been effective. There are too many ledges and other resting spots to place spike strips or similar things.

ANSWER:

Well, dadgummit. You shot down nearly all of my usual suggestions, but that won’t stop me from investigating them anyhow. What would surprise me would be if after 2 full years this location has not attracted more pigeons than just these two. Since you indicate there is an abundance of roosting / loafing locations within this shop it would be logical for other pigeons to enter as well. But, if it is really just this pair of birds then one final option you have not mentioned may be necessary, and that is to kill these birds, and shooting with an air rifle may be effective. It also may not be effective depending on the interior of this shop and what kinds of problems might occur from a stray pellet. But, years ago an expert from one of the major bird control products manufacturers made the comment that there will be times when that firmly entrenched bird or birds just will not leave their favorite sites no matter what you do, and killing them could be the last resort. 

You say that exclusion is not going to get any better. Is this because of the porous nature of the building or is it because of a lack of cooperation or effort on the part of the customer? If these birds have found a way to enter and exit every day for the last 2 years then obviously an opening or openings exist that are likely to allow more birds to enter in the future. Ideally what you strive for with bird management is to eliminate the problem without having to harm any birds, and this means some manner of exclusion. Either you eventually work to close off the entry points or you bit by bit install devices on the roosting ledges so that the birds never find any more places to land. This doesn’t have to be done all on one day, but over a period of time perhaps it could be accomplished. Netting and spike strips would be permanent materials on the inside of a building. 
Your prebaiting sounds like you may be using Avitrol, but of course even an effective bait like Avitrol is designed to move the birds, not to kill them, and moving the birds but leaving the opportunity to re-enter is not the long term solution. Trapping the birds also has its pitfalls. Catching them and releasing them anywhere in the vicinity is only going to allow them to return, and releasing them someplace other than “on site” may be illegal according to many states’ wildlife laws. 
For now the immediate resolution to this problem may be to shoot and kill these birds, but to work with the customer to exclude more birds for the future. The use of other kinds of “repelling” devices, such as physical objects that are designed to frighten the birds, could have some temporary effect, but pigeons generally figure out pretty quickly when something is not really harming them, and they begin to ignore it. If these birds have been here for 2+ years then this is their HOME, and they will not readily abandon it. 

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Pest QuestionsFebruary 25, 2012

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Feb 24, 2012 – Bats, and Not Even A Belfry

QUESTION:

I have an apartment building with bats in the end wall. The entry point is the flashing from the attic vent and brick. What is the best way to get them out?

ANSWER:

One of the first things to do, if it has not already been done, is to grab a chair and sit near that entry point beginning about an hour before dusk in the evening, and carefully watch to see if these bats are emerging to forage at night. Since you are in Texas it is very possible that they are remaining active throughout the winter months, and if they are then they are already doing the job for you by leaving each night to feed. This also should be too early for any new baby bats to be present, so this definitely is the time to do the necessary exclusion. But, check with your local university extension service to verify the species of bats that are found in your area and then brush up on their biology. You definitely do not want to seal out the adult bats and then leave a bunch of babies stranded inside, nor do you want to seal off that opening and leave some hibernating bats inside to die and create problems. 

It would also be advisable to do this evening inspection of other areas around this structure, since there very well could be multiple entry points that would need to be addressed. Once you have determined that the bats are, indeed, leaving the structure at night you can install a one-way door of some kind that allows them to leave but prohibits them from re-entering. This can be a tube of netting or other material that hangs down from that opening, allowing them to push through to exit but not to get back through. Once you are confident that all the bats are out the opening (or all openings) can be permanently sealed shut. 
I don’t know if you are able to access the actual voids in this end wall where the bats are located. If you can you might be able to make them uncomfortable with a couple of things – bright lights that illuminate the void or some kind of fan that creates a strong breeze in that void. Bats do not like these changes and it may encourage them to leave. There are bat repellents that can be placed within an area where bats are roosting, but these can NOT just be dumped into a void and forgotten. They must be placed within some sort of container that can then be removed once the bats are gone or if the odor of the repellent begins to bother the people who live there. These repellents often rely on naphthalene (moth balls) and this odor can be quite strong and objectionable to people. And, it is illegal to use plain old moth balls or moth crystals if they are not labeled specifically for use as an animal repellent. The internet is filled with recommendations like this, and we, as licensed professionals, must stick with labeled products. 

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Pest QuestionsFebruary 24, 2012

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Feb 21, 2012 – What For De-Licing

QUESTION:

What can you use to get rid of lice from your home?

ANSWER:

Whether or not there is any need to treat a home for lice depends heavily on what kind of lice these are, so once again accurate identification is necessary. Unfortunately, doctors often dish out the wrong information to their customers, and this muddies the water for our industry pretty badly. I also have seen serious mis-identifications of these kinds of things made by physicians, such as some crab lice that were ID’d by the family doctor as “bed bugs”. You can see the importance of ensuring that YOU actually see the pests that are present so you can make the proper ID and then proceed in the proper manner for management. 

There are lice and there are lice. Birds and rodents are frequently infested with chewing lice that do not feed on blood and are not going to attack people. The more likely lice in homes or on people are going to be our Big Three – crab lice, head lice, and body lice, and only one of these warrants any kind of insecticide treatment by a pest control technician, and this would be Body Lice. Head and crab lice are completely, 100% the role of a doctor to deal with by prescribing a medication or shampoo that will kill the lice on the people. These two species are unlikely to be found in the environment of the home, although this is not always the case. They stay on their host (people) but may be dislodged onto clothing, hats, bed coverings, or couches when a person with the lice comes into contact with those items. Then, a second person may acquire the lice if he or she immediately comes into contact with those items as well. These two lice lay their eggs on the host animal and both will die within 24-48 hours if they are unable to get back onto a person. Control is treatment of the infested areas along with laundering or hot drying of all clothing and other fabrics that may have the lice on them. 
Everything you read from reliable sources on crab and head lice tells our industry that we have no role in their management, and no insecticide applications around the home are needed nor would be of any benefit. Killing the lice and their eggs on the person as well as on personal items is what eliminates the problem, and some items may not be considered initially, such as bicycle helmets and other things an infested child may have been wearing. If this is head lice and on a child this needs to be addressed immediately to prevent the child from being kept out of school as well as to prevent the social stigma of a child infested with lice. Head louse infestations have a way of running wildly through elementary schools. 
If it is body lice then there may be some need to treat areas of a home. This species tends to remain more on the clothing, to lay its eggs on the clothing, and to move to the person only to feed before moving back onto the clothing. Control also should involve the same thoroughness of laundering in hot water and hot dryer any clothing that has been worn while the infestation was going on, along with all bedding and other fabrics that the lice may have gotten onto. Even a hot dryer cycle alone is going to kill all lice and eggs that may be on fabrics that you may not want to launder. If items are sent to a commercial dry cleaner the store personnel MUST be advised they are accepting potentially infested fabrics, so they can keep them separate from others in the facility until treated. 
There are about a dozen insecticides specifically labeled for Lice or Body Lice, and you can view this list on PestWeb in the Product Documents resource – choose “Products by Target Pest / Biting, Blood feeding / Body Lice”. The list includes both residual products as well as contact products for fogging, but the emphasis should be around areas where the clothing is stored. This would be where lice may move off the clothing or eggs hatch and initiate movement of new lice. Emphasize the laundering and hot dryer, a thorough vacuuming of areas such as furniture, and treatment of the lice directly on the infested person using a prescription product. 
But, try very hard not to get talked into spraying insecticides around a home for crab or head lice, as it is unnecessary and would do little in the overall effort. 

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Pest QuestionsFebruary 23, 2012

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Feb 22, 2012 – Is Resistance Forever?

QUESTION:

My question is concerning pesticide resistance and cockroaches. I realize that rotating the pesticides and type of pesticides is a good method for avoiding pesticide resistance, but if you do have pesticide in your inventory that roaches have developed resistance to would it be possible to bring that pesticide back into rotation 9 to 18 months later? My thinking is that the product should be out of rotation long enough and the resistance developed could possibly be defeated because they have not been exposed to that particular material in a while.

ANSWER:

I would say that bringing back a product within just a year, when you believe that resistance to it is being shown, would be far too early. And, as we have seen with the Common Bed Bug and its resistance to pyrethroids, the development of resistance is an evolutionary phenomenon that could linger in the genetic makeup of an organism for a very long time. Because of the constant exposure to DDT when it was first introduced for bed bug control these bugs quickly built up resistance to the molecule, and this resistance was an ability to block the effect – the mode of action –  of that molecule on the nervous system of the bed bug. Synthetic pyrethroids were introduced 3 decades later and really not even used heavily on bed bugs for another 20 years, but because the Mode of Action of pyrethroids is exactly the same as the Mode of Action of DDT the resistance popped up rapidly. Clearly the offspring of those bed bugs back in the 1950’s still had the mechanism for resistance built into their genes. 

However, according to some of our industry experts, The Common Bed Bug is a remarkable creature with an amazing propensity for developing resistance to MANY kinds of chemicals, whereas German roaches do not have quite the same ability. There definitely have been pockets of German roaches around the country where resistance has been demonstrated, but it takes a lot longer and is not nearly as widespread as with bed bugs. If we assume that the development of resistance is simply evolution in action – the survival of those individuals most suited to their environment – then when we constantly use a particular toxin we could continue to select for the survival of the resistant individuals and their subsequent generations. They became resistant simply due to a new hazard in their environment, and it’s possible that if that hazard is removed the species could “evolve” back to what was working previously, eliminating the genetic resistance and making them susceptible once again. 
But, this is just my speculation, and the better path to take would be to avoid developing that resistance in the first place by rotating your product usage on a regular basis. You would need to rotate to some other chemical family that has a different mode of action, and our new course in Master Technician – number 209 Insecticides Modes of Action – may be helpful in understanding this. Since all pyrethroids affect the roach in the same manner the resistance to one active ingredient should also show resistance to all other pyrethroids, as well possibly as to other chemical families with the same MOA. 
German roaches breed pretty quickly, with 4 generations each year possible, so they would be more likely to revert to “normal” than perhaps other species that take up to a year to mature and produce offspring. Of course, this short life cycle from egg to adult is also a reason why resistance can develop more quickly in the German Roach, as you more quickly get a group of offspring in which there may be a few resistant individuals. Because of the relative rarity of resistance by roaches it is far more likely that failures in eliminating these roaches from an account will be due to something other than resistance, such as missing pockets of the roaches in a treatment program or having more roaches enter the account. 
I like a comment made by Dr. Dreydon during a seminar on fleas years ago. He briefly commented on fleas and resistance to insecticides, which is often touted as the reason technicians are unable to eliminate a flea problem. He said, with respect to resistance, “it’s a crutch”. 

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Pest QuestionsFebruary 22, 2012

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Feb 19, 2012 – A PreTreat That Lasts?

QUESTION:

Is there anything we can use to pre-treat open walls or wall voids for control of insects? A restaurant is asking us to pre-treat for control of roaches, ants, etc. Thank you

ANSWER:

I think it would be important here to discuss with the customer just what his expectations are from a “pretreat” for insects like roaches or ants. I suspect that in his mind you should be able to apply something into this soon-to-be-enclosed void that will last for years to kill any of these insects that find their way in. This definitely is possible for wood infesting pests like termites or beetles. For them we can apply borates as sprays on the wood, and the insects must eat their way through that treated wood to get inside, consuming the borate in the process. Spraying borates on bare wood for insects that do not eat the wood is not likely to work in the same manner, and in fact products like BoraCare and TimBor are labeled only for WDO pests, probably for that reason. 

We can get the same lengthy residual from boric acid or borate products that are labeled for roaches and ants, but these generally are applied in dry dust form. Applying a dry dust to exposed wood surfaces is not a good option. Some of the products, such as Boracide, are specifically labeled for application to “new” or existing construction for ants and roaches, but the directions for use tell us to apply it as a dry dust directly into voids or insect galleries (as in carpenter ants). If these wall voids are currently open it would be difficult to contain the dust to the wood studs using any kind of pressurized duster. You could sprinkle the dust along the base plate, but if that is all you are able to do you could achieve much better coverage once the walls are in place and a power duster is used through some small opening into the void. Then you would get the dust onto the studs and interior wall surfaces as well, greatly increasing the odds that the insects will be in contact with it. 
Similarly Borid Insecticide Dust is labeled for pre-treating new construction for roaches. It recommends applying the dust at 4 lbs per 1000 square feet, but to “base plates and plumbing voids”, so you would not be able to successfully treat all of the studs nor the interior surfaces of the wall coverings. 
Those materials that you could easily spray over all of the exposed wood surfaces would have a relatively short lifespan. In contrast to the years of residual effectiveness of a dry dust of boric acid or diatomaceous earth, the spray-on “residual” insecticides may last a few months, and this may not be what the customer is thinking will happen. You can offer him this choice, but he may opt instead to have you “post” treat those wall voids with an inorganic dust product once the walls are in place, and this will give him the longest lasting material in those voids. 

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Pest QuestionsFebruary 21, 2012

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