Archive for the ‘Pest Questions’ Category

Jun 12, 2012 – Water and Pesticides

QUESTION:

How much effect does the pH of the mixing water have on the efficacy of Bifen 7.9 and what is the ideal water pH for mixing with Bifen 7.9?


ANSWER:

It is probably a good idea to know in general what the quality is of the water used to dilute pesticide concentrates, and for that matter even the pH of the soils and other surfaces you apply the sprays to. Water that is high in alkalinity (a high pH) is more likely to affect chemical molecules than one that is slightly on the acid side (lower in pH). If my basic chemistry knowledge is still correct the scale of pH runs from 0 to 14, with 0 being extraordinarily acidic and 14 being terribly alkaline (also called “basic”) and with 7 right in the middle as neutral. Plain, clean water is supposed to be right around 7.0, but when minerals are in the water it moves toward the basic side, and we call it “hard” water. That results in all the white deposits on cars after washing them if the water is from underground supplies. Water softeners remove those minerals so they do not build up inside pipes or the tubing of things like a coffee maker. 

What is preferred is a pH just slightly on the acid side, but each jump of one number is a 10-fold change in the acidity or alkalinity, so water with a pH of 9 would be 10 times more alkaline than water with pH 8. A simple swimming pool test kit should be sufficient for testing the waters you use in your tanks. 

The effect of pH, and in particular alkalinity, was much more of a concern with our old Organophosphates and Carbamates than it is with the current Synthetic Pyrethroids. Whatever the chemical reason for it, the OP and Carbamate molecules were really affected by alkalinity and tended to break apart. One vendor rep for a carbaryl product told us once that adjusting the pH down from alkaline to acidic could extend the life of the product on foliage from 1 day to nearly 60 days. Now, that could be pretty optimistic, but it at least demonstrates the huge benefit of using slightly acidic water for those classes of pesticides. The pyrethroids do not seem to be nearly as susceptible to alkalinity and it really has not been an issue pushed by the manufacturers of these products, but I suspect it would still pay to test the pH and keep things close to neutral at least. 
Adjusting the pH is simple, and Univar ES sells a number of “buffering agents” that will bring the pH down, as well as some other general surfactants that include a buffering agent. These can be added to the tank when you mix the products for use. We also know that some surfaces may have a high pH, such as concrete or stucco or sheetrock, although paints may cover these to reduce the alkalinity of the actual surface you treat. But, unfinished surfaces might have an effect to more quickly break apart pesticide molecules and reduce the residual effect. 

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Pest QuestionsJune 14, 2012

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Jun 13, 2012 – Pyrethroids On The Cruise Ships

QUESTION:

How will the new 2012 pyrethroid label requirements affect pest control done on board large ships? Can pyrethroids still be used on open decks?

ANSWER:

I would say the answer will be no, pyrethroids would not be allowed for use on exterior decking that would be exposed to rainfall or washing that could then allow that product to enter the water around the ship. The new pyrethroid wording states that it is intended for use of pyrethroids on “man-made structures”, and certainly ships and other kinds of boats or “vessels” would be man made structures. So, without offering too many specific kinds of structures we have to assume the new restrictions would include ships. 

The best way to look at this is probably to observe where the material is being applied, and whether or not that surface will be subject to rainfall or irrigation or some other manner of water getting on it that is then likely to run off that surface. The EPA does distinguish between “impervious” surfaces such as decks and driveways versus surfaces such as lawns or soils where the spray treatment will be able to be absorbed and to stay put. Further, if that soil or turf is already saturated with water and is on any slope then it is likely the added water of a pesticide spray will run off the surface and end up in a gutter or creek. I’d swear you could fish for salmon in some of the gutters around my city where sprinklers are aimed poorly or operate for so long that the water is simply flowing off the landscape and into the gutter and then quickly into the local creeks. 

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Pest QuestionsJune 13, 2012

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Jun 9, 2012 – Fleas Outdoors

QUESTION:

What is the best method and product for exterior flea control?

ANSWER:

We’ll get the “product” part of this out of the way first by suggesting that MANY products are labeled for flea management outdoors and all of which will kill the fleas successfully. A popular active ingredient is permethrin, and Dragnet SFR is the original product containing this a.i. It is a pyrethroid, and thus subject to the new label restrictions found on all pyrethroids, but your applications outdoors for fleas are not going to be on “impervious” surfaces such as patios or driveways. These would just not be habitats where flea larvae are going to be living and developing, and thus would not need to be treated for the larvae. If you have a lot of adult fleas hopping around on paved areas that could not legally be treated with a pyrethroid you would have to use an alternative product or simply spray with pyrethrum to kill the adult fleas present there. 

It is very important to determine exactly where the fleas are coming from. The complaint is going to be about adult fleas, and I have seen major infestations of adult fleas on paved areas. Clearly this is not where they originated, but they “hopped” their way to that pavement from some site where the larvae were developing, and this will be a moist, cool, shaded habitat that is conducive to the survival of the larvae. It also will be where those larvae can find their required foods, one of which must be dried fecal material from adult fleas, telling us that this micro-habitat of the larvae must be a place where host animals spend time – dogs, cats, raccoons, etc. Look for these places where the large animals would spend time and focus your treatment on those places. If you do not eliminate the SOURCE of the problem you can kill all the adult fleas you want and they will continue to be produced. 
Outdoor habitats could be under decks, where leaves accumulate, moisture is retained, and shade is provided. Cats and other animals love to reside under decks, so these need to be addressed to permanently exclude those animals. You then can remove as much of the debris as possible under that deck and treat the soil with a contact insecticide. Dense plantings of ground cover or shrubbery also provides resting habitat for warm blooded animals, and every time they go there they seed that substrate with flea eggs and dried blood feces from the fleas on them. Removing layers of plant material on the soil and trimming the plantings to expose the soil to sunlight will help to alter the environment and make it less conducive for flea larvae to survive there. As one flea expert stated in a seminar, treating the open, sunny places for fleas will do very little. You also have no need to spray dry, dusty soils, as these too are not appropriate breeding locations. Focus on the places where animals may go during hot days, looking for shade and cooler places to rest. 
An IGR may be helpful along with the residual contact product, but do not use Precor or any other methoprene product outdoors. This IGR does not hold up in sunlight and generally is not labeled for exterior use. Go with a nylar product instead and there are many, Archer being one. 

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Pest QuestionsJune 12, 2012

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Jun 10, 2012 – Retreating And Labels

QUESTION:

Do they class a spot treatment on the outside of a premises with Termidor as part of the two treatments a year? If I have treated a foundation and in between the first and second treatments per year I find trailing ants, can we spot treat them? It does not say anything on the label about it so thought I would ask the question.

ANSWER:

Label interpretation is always a delicate issue, and I suggest it is best to err on the side of caution. The Termidor label states rather bluntly “DO NOT exceed the maximum of two applications per year”. Since it does not modify this restriction in any way I suggest that if you were to make ANY application on the exterior of a structure that is an “application”, and two of these in any calendar year is the limitation. It does not necessarily mean that you could go back a third time and treat surfaces that were not actually sprayed on the first or second applications. This is such an important product for us for ant control that we need to be sure to toe the line and stay within what the Label clearly allows. 

So, for that call back for ants after your first application, if you choose to use Termidor again to resolve this “in between” problem I would say that you now have made your second application, and any plan you had to use it later in the year would be interpreted as a third treatment and now off-label. Better to go with one of the many other products that would be allowed and which also could be very effective for ant management, including baiting in strategic places to allow the ants to take bait into the colony. We do have an up and coming arsenal of other non-repellent insecticides, some of which seem also to offer a decent transfer effect, that help us with ant control. 

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Pest QuestionsJune 12, 2012

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Jun 11, 2012 – Out of Sight, Still There

QUESTION:

Do cockroaches in the desert Southwest states burrow into the ground?

ANSWER:

The cockroaches comprise a very large group of species in North America. We tend to think of them in terms of the pest species that invade our structures and often set up their own homes inside, such as German, American, Oriental. But, there are many other species, and some of these are native species that have adapted well to living in the conditions in their chosen environment. The desert species have adapted to living with very little moisture, but still need to hide in darkness and stay out of sight, and for this they may very well burrow into the soil. I have found some light colored species myself in the Mojave Desert, hiding in the sandy soils around the base of plants, or under fallen plant materials resting on the soil. 

So, yes, it is very possible that you have some regional native species that may be discovered when someone uncovers their hiding places. You are going to have far fewer problems with the large exotic species such as American and Oriental, living in the landscape outside structures there in Las Vegas. They have such a high requirement for moisture that the dry climate is just too harsh for them. This is not to say there will not be any of them, as they nicely adapt to what we offer, such as underground passages like storm drain systems and sewers. But, they just will not do as well as they might in the wetter, more humid southeastern parts of the U.S. 
Another species that has managed to enter and continue to live in the U.S. is the Surinam Cockroach, and this is more common along the southeastern states to Texas as well, but found now and then inside structures in other parts of the country. This is probably a native of South America, but travels to new places in the soil of plants, and I have seen it in California, although rarely. It prefers to burrow in the soil to hide during the daylight hours, and you might find this in the soil of interior plants or in commercial interiorscapes. 

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Pest QuestionsJune 11, 2012

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Jun 4, 2012 – Wharf Borer Wars

QUESTION:

I am an exterminator in NY and service a bar/restaurant that each spring has a problem with wharf borers. They are not present in large numbers but they do resemble German roaches so each one is a problem. The place is over a large unfinished basement that is always wet or at least damp, although the floor beams of the restaurant are high enough to stay dry. The literature is a little sparse on wharf borers. What can you suggest?



ANSWER:

Wharf borers are beetles in the family Oedemeridae, and yes they could somewhat resemble German roaches, although a close look by anyone qualified to make an ID would separate them. They lack the black stripes on the thorax that German roaches have and are an overall orange color with a black patch at the tips of the wings. I assume that the problem comes when patrons of this restaurant see one and think the place has roaches. The adult beetles do not even feed and are of no concern whatsoever, other than the fact that they are going to make more of their kind. 

The literature on these beetles states consistently that they feed only on wood that is very wet and even rotting. Dry wood is not attractive to them, so obviously the continual dampness of the wood in this basement is the attraction, and at some point in time the owners really should address that problem before the place falls in. If any of that very wet, decayed wood is of structural importance it eventually is going to lose its strength and the restaurant will have much bigger problems on their hands. Perhaps they should consult with an engineer or someone else qualified to give advice on how to place moisture barriers to prevent the moisture problem. This might be as simple as just covering the soil with the proper moisture barriers to keep the soil moisture from entering the air in that unfinished basement and to keep the wood drier. 
Ending the moisture problem is, of course, the best long term solution to this problem. If the customer is unwilling to do this for some reason you may consider a treatment of the wood, assuming all the wood there is also unfinished, with a borate product like Bora-Care. This will soak into the wood and hopefully kill any beetle larvae feeding within. It also will help to kill wood decay fungus that probably is present there as well. But, the better solution is moisture barriers properly installed so that the wood that attracts the beetles dries out and no longer draws them. 

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Pest QuestionsJune 06, 2012

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Jun 2, 2012 – A Smelly Result

QUESTION:

Any advice on how to eliminate the odor from dead rats?

ANSWER:

Ah yes, the drawback to the use of rodent baits by untrained people, such as the DIY homeowner who does not recognize that rats that die from toxic bait may die just about anywhere, including within hidden voids or other difficult to access places in the structure. They also may be victims of that oft-given advice (and myth) that the baits “make the rat thirsty” and cause it to go outside to die. This one has no truth to it at all, and we need to educate our customers on the facts. Rodents that feed on anticoagulants also do not “dehydrate” to prevent foul odors, another well known non-truth. 

If we look at the odors of dead animals as another kind of “pest” we recognize that the best approach if it is possible is to find the source and eliminate it. We can collect foul odors and we can mask them with other odors, but as long as that decaying rodent is still present and decaying it is going to stink, and even after it has somewhat dried it will continue to give off the awful smells. This could take some time to complete, so if you can make a careful search using your nose as a guide perhaps you can locate the dead animals, carefully place them within sealed plastic bags, and dispose of them. Doing this enables you, then, to thoroughly cleanse that area to remove any remaining traces of the rodent, which also could continue to create smells and attract flies. There may also be a need to treat that location with a contact insecticide to ensure any wandering parasites from the rodent are killed, such as mites and fleas. The use of an anti-bacterial disinfectant may be appropriate for cleaning the surfaces the rodent rested on, or you may even want to gather and toss loose material there such as insulation. 
If you cannot locate the offending source itself then you are stuck with trying to treat the odors from a distance. If you know it is within a wall but the customer does not want the wall damaged by opening it then you may be able to use a void injector fogger to blow a deodorant mist into the voids. Univar carries a number of effective liquid deodorizers that do not just mask the odor with a stronger one, but which are microbial in nature and actually feed on the molecules that are creating the smell. These may be products such as Bac-A-Zap, Rat Sorb, or Odor Hunter. Some of these come in small spray bottles for use on the surface itself where that dead rodent was lying, and are always more effective when applied directly to the surface. 
I also have received good feedback from PMP’s who have used the dry deodorizers, such as the Odor Remover Bags and Pouches. These can be placed or hung in the area where the odor is strongest and according to the manufacturers they will remove the odor from the air itself. It sounds magical but the results have been very good. 

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Pest QuestionsJune 04, 2012

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Jun 3, 2012 – With Mice Come Ticks?

QUESTION:

I have a service with a large property management company, mostly commercial but with a few residential. I think I have done a good job with very good feedback from clients. I have serviced the residential apartment units for 2 years with no negative feedback. However, I currently am working on a mice issue for a “sensitive” client in one apartment. I have excluded the single mouse from her unit that was entering from a hole behind the fridge. I filled this with copper mesh, sealed with silicone and then put 1/4 hardware cloth over that. I feel I am done and now this client wants to spray for Lyme ticks inside her apartment! She thinks they will drop off the mice and bite her. Is there any chance this could happen? Is it not true that other than a dog tick other ticks like Lyme ticks cannot complete their life cycle inside? If there were a couple of mice in a wall is that a Lyme Disease danger?

ANSWER:

You have some challenges here, so let’s discuss them first. You have a very important client in the Property Management Company and need to keep them satisfied that you are doing the best control you can, which seems to be the case so far. However, now they have a single tenant who is, perhaps, overly obsessed with the idea of Lyme Disease ticks being in her apartment, and if SHE is not satisfied that you have eliminated that threat then she is likely to make a loud and persistent complaint to the property management company. Your problem may be compounded by your need, or requirement, to verify the presence of a pest before you spray a pesticide, and if your best efforts do not find any ticks or other mouse parasites in this apartment you might be spraying a toxic substance there for no reason. This may be illegal in your state, and this is why I often encourage technicians to make the call to their local pesticide regulatory office and get their opinion. It may be that a single treatment with a properly labeled insecticide would resolve this tenant’s worries and make everyone happy, but you need to be sure that you are doing so legally. Ultimately you need to please 3 different people or agencies. 

Lyme Disease is certainly prevalent in your area of the Northeast, but Lyme Disease ticks (Ixodes) are much more associated with white footed mice, deer mice, and other Peromyscus than with the House Mouse. But, the House Mouse is “capable” of acquiring Ixodes ticks when active outdoors and therefore “capable” of bringing them indoors, and thus we could not in clear conscience tell this tenant that it is impossible for her to be exposed to these ticks. It is possible, just unlikely. I agree with you that the Brown Dog Tick is one of the few kinds of ticks that can complete its life cycle on humans, so without furry animal hosts available the infestation would not continue even if some of the ticks were now within this apartment. If the question then gets to “well, what about mice in the walls”, again we could not make unrealistic guarantees. If there were mice there and if they had ticks on them then those ticks or their offspring could make their way out through wall outlets, etc. 
It may be important in all of this to recognize that baby ticks (larvae) do not emerge from their eggs infected with the Lyme Disease bacteria. They must acquire it by feeding on some infected animal, so this further reduces any chance that this client could be exposed to ticks that are infected with the disease. Even if those few mice dropped a gravid female tick and she deposited her mass of eggs in the apartment, the emerging first instar ticks would not be infected. 
It is not unusual nor improper to treat an area around a wild animal nest for probable parasites from that animal, such as indoor bird or rodent nests. We know very well that these nests may harbor high numbers of arthropod parasites that could move from there to bite people. So, with your local regulatory agency’s approval, doing a one-time treatment with a product labeled for this indoor use might be appropriate. We don’t always see the fleas in a home but can recognize that the presence of infested pets and complaints of bites tells us there is a high likelihood that fleas are present. I would suggest you balk at any demand to continue to treat this apartment on every visit, but a single treatment to eliminate any wandering parasites that could be dropped by the mice could be appropriate. But, DO consider maintaining a lot of insect glue traps in the apartment, and inspect them every visit. Hopefully after a few months of no ticks on the traps the tenant will be more comfortable that any threat is eliminated. 

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Pest QuestionsJune 03, 2012

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May 31, 2012 – Insects And Public Health

QUESTION:

As pest professionals we likely want to feel we are offering a legitimate and valuable service other than just killing bugs because they are icky and annoying. This pertains in particular to vector control and the pathogens arthropod pests are known to transmit to people. Do you know of any great source that will list some of these various pathogens? I know I can find some here and there, but does the CDC, for example, have this information compiled all together? I know pest control is recommended for most homes and buildings to control potential vectors such as roaches, ants, and other insects, and we fight with the occupants over the subject of sanitation and its role in the presence of the pests. So, do pests really make people sick?
Also, I notice that a lot of outdoor flying pests will run to and rest on the lower parts of buildings. Is it better to spray a barrier treatment higher up as to kill less of these? Is a barrier treatment actually helpful in deterring pests (including ants) from crawling up the building?

ANSWER:

The bottom line for one of your questions is that ABSOLUTELY arthropod and rodent pests will make people sick, and coincidentally we posted a news article just today on PestWeb’s “Pests In The News” that highlights a new and growing epidemic with Chagas Disease, a terrible disease vectored by kissing bugs and so common in Latin America that at any one time up to 8 MILLION humans are infected with the disease, with many tens of thousands of them dying annually. Sadly, I would bet that almost no one in the U.S. is even aware of the disease outside of those in pest management. This is all about to change though, with the new publicity this disease is now going to receive, as new evidence tells us that there may be as many as 300,000 people in the U.S. are now infected, many of them immigrants who may have come into the U.S. already infected, but serving as the reservoirs for the pathogen to infect other people. 

The list of insect and arachnid (ticks, mites, etc.) borne pathogens is virtually endless, and new ones are discovered all the time – witness the relatively recent knowledge of Hantavirus, Lyme Disease, West Nile Virus. Entire books are dedicated to the topic, such as one of my old textbooks in Entomology just called “Medical Entomology”. However, the Internet is our new Encyclopedia, and with just a few key words you can find what you are looking for. I “Googled” “insect borne disease list” and found nearly 2 million possible hits, including the Centers for Disease Control. This brilliant website not only lists all of the diseases, but also offers statistics on where they are occurring, vaccinations recommended for travel, etc., along with fact sheets on most of them. 
The American Mosquito Control Association is also going to offer the same kinds of thorough lists of pathogens vectored by insect pests. There are books and websites, such as the Avitrol and Bird Barrier websites, that list all of the diseases associated with birds. Similarly books and websites list all of the rodent-borne diseases. So yes, with just a short search you will easily find compilations of the information you want. 
With respect to treating outdoors, it sounds like you prefer to avoid killing many of those flying insects that occur sitting on structures but which are really not pests. Thank you for that attitude, and it is one I strongly encourage. We need to spend just a little more time properly identifying the bugs that occur in homes and yards and avoid spraying insecticides when those bugs do not need to be killed. A landscape is much better off with many insects and spiders living in it than without any of them. Barrier treatments around the base of the structure can be effective in intercepting crawling insects, so the use of contact insecticides is a very legitimate use of the products. Perhaps it is unfortunate that some beneficial insects are also going to be affected by these applications, but it may be unavoidable. It is hard to pick and choose which critters come crawling along the base of the foundation at night, and in order to keep out the earwigs and ants and crickets there may be some spiders and soldier beetles killed as well. 

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Pest QuestionsJune 02, 2012

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Jun 1, 2012 – Frass In Many Forms

QUESTION:

Yesterday I inspected a log home and found this very fine frass everywhere falling from the ceiling and hanging from spiders’ webs. A lot of acrobat ants were present in trails in several areas in the home as well. Inspecting the structure also showed what looked like evidence of ambrosia beetle damage with the blue to black staining on the wood on walls and cross beams. My question is, could the frass be from the acrobat ants or the beetles? No evidence of beetles was found anywhere in the structure, some mold was present on the cross beams, and water damage was present in the top of the structure.

ANSWER:

It would be very important to gather some of that “frass” and take a very close-up look at it, preferably through a dissecting microscope that allows you to see details. The term frass refers either to fecal material that wood-eating insects like beetles might produce, or to sawdust and wood debris created by insects like ants, that do not eat the wood but which excavate cavities and then keep them cleared by pushing out unnecessary debris. Fecal pellets are going to have a more defined shape and would be more compact and oval, whereas sawdust frass has a haphazard look to it and obviously has not been run through the bug’s system. Quite often, if it is frass from ants, you also will find other things in the mix. Carpenter ants are the classic WDO ant, and within the frass you often find pieces of other insects that they fed upon, parts of dead ants that died within the colony, and white silk pupal cases that were no longer needed once the adult ant emerged. I once was handed a jar of “frass” that kept appearing near a fireplace, and to the naked eye it looked like dirt but under good magnification was clearly hundreds of dead ants. 

If this is a beetle infestation the most likely culprits would be deathwatch or furniture beetles in the family Anobiidae. Their fecal matter is dry and loose and falls from the feeding galleries through the exit hole of the adult beetles. However, you then should be able to find lots of small, round holes in the wood above where this frass is occurring. As far as the possible evidence of ambrosia beetles, if this is being seen on the surface of the finished wood then it more likely is just old feeding galleries that were present when that wood was milled for lumber, and the galleries within the wood were exposed when the saw moved across them. It would be against the nature of any of the wood eating beetles to feed on the surface of the wood, and ambrosia beetles actually feed on a fungus that is cultivated within the channels in the wood. 
I suggest starting with that careful ID on the frass itself, determining if it is fecal pellets or sawdust. Then you can proceed with a more careful inspection once you know it is either beetles or ants creating it. While carpenter ants are the most common group causing damage in wood, other kinds of ants could also enlarge cavities they find and push the sawdust out. In the western U.S. we have the common “black velvety tree ant” that is extremely common in forested areas of the mountains, and which is the culprit when large piles of sawdust are accumulating on window sills and floors. 

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Pest QuestionsJune 01, 2012

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