Apr 19, 2012 – If Not Pyrethroids, Then What?
QUESTION:
Some of the recent changes to pyrethroid labels have encouraged me to want to check into changing a main liquid spray. I am pretty sure pyrethroids are the most popular chemical class among many GHP professional applicators, and maybe even over-the-counter residential premade products. Do you think this is going to sway many PMPs away from pyrethroids, and if so, can you offer some suggestions as to what might be some good alternative chemical classes and products? Are there replacements available that come close to pyrethroids in effectiveness, use of ease, and safety? This is a label change that I think is going to really affect me in terms of time spent and practical effectiveness. I think the 3 feet above foundation restriction is too stringent and, in my opinion, should be paired with a statement such as "if within 75 feet of to-bay drain or lake/pond/etc" because, in my opinion, if the product residual adheres to the surfaces the label states they do, then the notion of so much washing away doesn't seem as credible.
ANSWER:
I think we need to accept that the use of "pesticides" will always be a politically charged issue, and that there are always going to be vocal, well financed groups that demand the elimination of all use of pesticides. It would be a mistake on our part to believe that each of their major offensives (DDT, Chlordane, Methyl Bromide, Alar, Pyrethroids) is all that they are after once they gain a victory. Instead, they will simply move onto the next most popular group of products in use and resume the attack. The pyrethroids are just the latest, and it all has to do (on the surface at least) with the potential effects on aquatic organisms when pyrethroids find their way into streams and ponds. This is what generated the latest restrictions on where we are permitted to apply pyrethroids, and any impervious surface that could possibly be exposed to rainfall now will have limited application allowances.
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Some of the recent changes to pyrethroid labels have encouraged me to want to check into changing a main liquid spray. I am pretty sure pyrethroids are the most popular chemical class among many GHP professional applicators, and maybe even over-the-counter residential premade products. Do you think this is going to sway many PMPs away from pyrethroids, and if so, can you offer some suggestions as to what might be some good alternative chemical classes and products? Are there replacements available that come close to pyrethroids in effectiveness, use of ease, and safety? This is a label change that I think is going to really affect me in terms of time spent and practical effectiveness. I think the 3 feet above foundation restriction is too stringent and, in my opinion, should be paired with a statement such as "if within 75 feet of to-bay drain or lake/pond/etc" because, in my opinion, if the product residual adheres to the surfaces the label states they do, then the notion of so much washing away doesn't seem as credible.
ANSWER:
I think we need to accept that the use of "pesticides" will always be a politically charged issue, and that there are always going to be vocal, well financed groups that demand the elimination of all use of pesticides. It would be a mistake on our part to believe that each of their major offensives (DDT, Chlordane, Methyl Bromide, Alar, Pyrethroids) is all that they are after once they gain a victory. Instead, they will simply move onto the next most popular group of products in use and resume the attack. The pyrethroids are just the latest, and it all has to do (on the surface at least) with the potential effects on aquatic organisms when pyrethroids find their way into streams and ponds. This is what generated the latest restrictions on where we are permitted to apply pyrethroids, and any impervious surface that could possibly be exposed to rainfall now will have limited application allowances.
Personally, with these latest restrictions I wonder if we should be pleased that we still are permitted to apply pyrethroids up to 3 feet above grade in a continuous band around a structure. I suspect that allowance is causing the anti-pyrethroid folks to grind their teeth pretty badly. California, where this issue was generated, might very well add further restrictions on the use of pyrethroids, and ultimately all other pesticides, within certain distances of aquatic habitats or even on habitats where water may "drain to" aquatic habitats or habitats of endangered and threatened species. This is not a battle that is going to end, so it is imperative that our industry stay involved to accomplish the best compromise possible. It would be negligent of our government to eliminate our ability to control public health pests in the search for environmental purity. Unfortunately, politicians and the media are generally sympathetic with any group claiming to have an "environmental" cause.
So, I think we can call these first 2 paragraphs "my opinion". With respect to alternatives to pyrethroids, I believe we are having a great many new chemical families introduced with many excellent active ingredients. The pyrethroids offered some highly attractive features, one of which was their very broad labels that often allowed applications over entire surfaces of structures. This, coupled with their excellent action on crawling pests, made them good choices for perimeter invaders and for over-wintering pests such as cluster flies, stink bugs, lady bugs, etc. We could make broad applications to the sides of the structures to help kill these insects as they arrived.
We are not entirely without this ability today. We still can apply large "spot" applications to sides of structures and the eaves are "exempted" from the limitation of spot treatments, so we still may apply the pyrethroids as needed in many cases. We still can treat crack and crevice, so effective treatments under siding and around windows or doors can be done, and this probably is more effective than the outside surface application. However, obviously it will be much more time consuming to do, so our residential customers need to be made aware of these label changes and to accept that how we do our business is going to change.
I won't say that I have carefully examined EVERY label of non-pyrethroid alternatives, but those I have looked at do not seem to offer the same allowance for a broadcast treatment of exterior surfaces. Yes, I suspect that many PMP's are going to look desperately for an alternative to the pyrethroids that would allow them to continue their applications in the same manner. But, it may be that these do not exist, at least not with the residual and other features of the pyrethroids. Some of the possible alternatives include thiamethoxam (Optigard Flex) that has interesting exterior labeling, acetamiprid (Transport GHP), and indoxacarb (Arilon). Of course we have the increasing trade names with fipronil as well, and these labels may expand their uses. I apologize to those vendors whose products did not get mentioned, but this is just a short list.
Add to this the many botanical insecticides that use plant-derived active ingredients, and some of these are going to have very broad labels and may begin to compete with the synthetic actives for residual and contact effectiveness.
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