Aug 4, 2011 – Practice and Pesticide Make Perfect?
QUESTION:
I'm having trouble with German roach treatments. I use Cykick CS, Delta Dust, and multiple baits. How long after initial treatments should I do a follow up for best results? Do you have a suggestion for the perfect product for residential use?
ANSWER:
I would say that the products you are using now should be perfectly capable of killing every cockroach that comes into contact with them for the necessary length of time. However, it always is a good idea to rotate the products you use now and then, rather than constantly using the same active ingredient over and over again, as this is one way that we can select for resistance to an active ingredient or even a family of materials. If cockroaches become resistant to a pyrethroid they could be resistant to all pyrethroids, as all pyrethroids attack the nervous system of the bug in the same manner, and resistance means that the roaches have developed a mechanism for blocking that action on their systems. "Resistance" does not mean "immunity" however, so even roaches that are resistant to an insecticide would still be killed by it if they absorb enough of the active ingredient.
It' human nature to assume that something must be wrong with the insecticide when we start having problems controlling the pest, and since resistance could occur this cannot be fully ignored. However, most often the problems begin when we do not locate all of the insect harborage sites, and therefore do not treat them. Cockroaches and many other insects are capable of detecting something on a surface that is irritating to them, and pyrethroids could create a behavioral avoidance by the roaches. It is possible (don't know if it has been demonstrated) that roaches could sense the presence of the pyrethroid as an irritant to their system and just choose not to rest or walk on a treated surface. Microencapsulation, as with the CyKick CS, tends to greatly reduce this repellency, so that should not be a factor for you. Instead, I would choose the more likely path that there are roaches hiding in places that have not yet been found and treated.
Still, it is a good idea to alter your chemical choices, and perhaps go with an inorganic dust like diatomaceous earth or silica gel instead of a pyrethroid dust. Alternate to a non-pyrethroid for the contact treatment, and there are so many new chemical families on the market that I hesitate to pick just one. But, products like Phantom, Acelepryn, imidacloprid products, Alpine and Optigard products, and Transport are options that all provide good results. I used to comment on the need to keep odor in mind when treating residences, but nearly all of our insecticides today have very low to no odor, so that is not as much of a consideration. For bait products it also is good advice to alter the choices, as this avoids behavioral resistance as well. If the roaches simply lose their appetite for one particular bait they will stop eating it, so offering choices helps keep them interested. Alter the formulations though, using granular baits within wall voids, gel baits within crevices, and stations stuck under cabinets or drawers.
The main thing is thoroughness and the placement of the contact insecticide directly into the harborage site. Do not treat baseboards or "band" treatments for German roaches, as they just don't spend much time sitting on exposed surfaces. You get the most contact time placing the active ingredient onto the surfaces the roaches will sit on for all those daylight hours. Don't ignore the use of aerosol formulations for the crack and crevice treatments. Aerosols are easiest to apply into crevices and to keep in the crevice, as the solvents in the aerosol evaporate rapidly rather than running out like a water-based spray will do.
View past Ask Mr. Pest Control questions.
I'm having trouble with German roach treatments. I use Cykick CS, Delta Dust, and multiple baits. How long after initial treatments should I do a follow up for best results? Do you have a suggestion for the perfect product for residential use?
ANSWER:
I would say that the products you are using now should be perfectly capable of killing every cockroach that comes into contact with them for the necessary length of time. However, it always is a good idea to rotate the products you use now and then, rather than constantly using the same active ingredient over and over again, as this is one way that we can select for resistance to an active ingredient or even a family of materials. If cockroaches become resistant to a pyrethroid they could be resistant to all pyrethroids, as all pyrethroids attack the nervous system of the bug in the same manner, and resistance means that the roaches have developed a mechanism for blocking that action on their systems. "Resistance" does not mean "immunity" however, so even roaches that are resistant to an insecticide would still be killed by it if they absorb enough of the active ingredient.
It' human nature to assume that something must be wrong with the insecticide when we start having problems controlling the pest, and since resistance could occur this cannot be fully ignored. However, most often the problems begin when we do not locate all of the insect harborage sites, and therefore do not treat them. Cockroaches and many other insects are capable of detecting something on a surface that is irritating to them, and pyrethroids could create a behavioral avoidance by the roaches. It is possible (don't know if it has been demonstrated) that roaches could sense the presence of the pyrethroid as an irritant to their system and just choose not to rest or walk on a treated surface. Microencapsulation, as with the CyKick CS, tends to greatly reduce this repellency, so that should not be a factor for you. Instead, I would choose the more likely path that there are roaches hiding in places that have not yet been found and treated.
Still, it is a good idea to alter your chemical choices, and perhaps go with an inorganic dust like diatomaceous earth or silica gel instead of a pyrethroid dust. Alternate to a non-pyrethroid for the contact treatment, and there are so many new chemical families on the market that I hesitate to pick just one. But, products like Phantom, Acelepryn, imidacloprid products, Alpine and Optigard products, and Transport are options that all provide good results. I used to comment on the need to keep odor in mind when treating residences, but nearly all of our insecticides today have very low to no odor, so that is not as much of a consideration. For bait products it also is good advice to alter the choices, as this avoids behavioral resistance as well. If the roaches simply lose their appetite for one particular bait they will stop eating it, so offering choices helps keep them interested. Alter the formulations though, using granular baits within wall voids, gel baits within crevices, and stations stuck under cabinets or drawers.
The main thing is thoroughness and the placement of the contact insecticide directly into the harborage site. Do not treat baseboards or "band" treatments for German roaches, as they just don't spend much time sitting on exposed surfaces. You get the most contact time placing the active ingredient onto the surfaces the roaches will sit on for all those daylight hours. Don't ignore the use of aerosol formulations for the crack and crevice treatments. Aerosols are easiest to apply into crevices and to keep in the crevice, as the solvents in the aerosol evaporate rapidly rather than running out like a water-based spray will do.
View past Ask Mr. Pest Control questions.
