Aug 8, 2011 – The Options For Roaches
QUESTION:
When treating for German roaches inside a home or apartment is there a product that provides a contact kill other then an aerosol, and have you found that gel baits are the best form of treatment?
ANSWER:
The word "contact" kill could represent two things. It could mean that the product is destined to kill an insect only at that moment of contact when you are applying it, and this generally refers to the use of pyrethrum. This active ingredient and many of the other natural plant based insecticides really offer no residual, so they can be applied in the hope that you directly treat the insect and kill it at that time. However, "contact" also could refer to the ability of an active ingredient that does have a residual to be on a surface when some insect wanders on to it, and the active ingredient is able to be absorbed into the insect by this contact. It does not have to be ingested as baits do, but simply moves through the cuticle of the exoskeleton and into the nervous system of that pest insect. All of the pyrethroids and the many other new families of insecticide chemistry are residual materials that operate in this manner.
Aerosols that contain these residual active ingredients are excellent for German cockroach control, since applying the material directly into the hiding places is the best way to get the longest contact time between the roach and the active ingredient. Treating along a baseboard or some other exposed surface in the hopes that the roach will come out of hiding and stand on that treated surface later is pretty optimistic. Treating exposed surfaces also increases the chances that people or pets will also contact the insecticide, or that food contamination could occur. Putting the material directly into the cracks, crevices, and voids where the roaches hide protects the active ingredient from being removed by washing, protects it from UV light, removes it from human or food exposure, and again, increases the contact time by the pest.
Where you hope for true and legal crack-and-crevice treatments you want to have none of the spray material dribbling or running out of that crevice, and water-base sprays are hard to contain in this manner. The water just too easily flows back out or splashes back from a shallow crevice, and the water takes too long to evaporate. Where a product Label MANDATES "crack and crevice only" applications this would be an illegal application properly called "spot treating" if it runs out onto exposed surfaces. Aerosols use solvents and diluents that evaporate rapidly, and are easier to retain in the crevices. So, many of the active ingredients in aerosols do give that contact kill, either on contact at the moment of the application or later when the roach rests on the treated surface.
Baits are excellent for German roaches, and gel baits still prove to be good choices. These should be incorporated into the overall treatment program. But, German roaches prefer to feed in seclusion if possible, so gel baits should never be applied out in the open on counters or other surfaces. They should be placed as "pea-sized" spots directly into crevices or gaps or small voids, taking advantage of the roach's preferencees. But, granular and dust baits also work when you can apply them into voids or use them in stations, and offering a variety of baits in a variety of formulations increases the odds that the roaches will accept some bait.
View past Ask Mr. Pest Control questions.
When treating for German roaches inside a home or apartment is there a product that provides a contact kill other then an aerosol, and have you found that gel baits are the best form of treatment?
ANSWER:
The word "contact" kill could represent two things. It could mean that the product is destined to kill an insect only at that moment of contact when you are applying it, and this generally refers to the use of pyrethrum. This active ingredient and many of the other natural plant based insecticides really offer no residual, so they can be applied in the hope that you directly treat the insect and kill it at that time. However, "contact" also could refer to the ability of an active ingredient that does have a residual to be on a surface when some insect wanders on to it, and the active ingredient is able to be absorbed into the insect by this contact. It does not have to be ingested as baits do, but simply moves through the cuticle of the exoskeleton and into the nervous system of that pest insect. All of the pyrethroids and the many other new families of insecticide chemistry are residual materials that operate in this manner.
Aerosols that contain these residual active ingredients are excellent for German cockroach control, since applying the material directly into the hiding places is the best way to get the longest contact time between the roach and the active ingredient. Treating along a baseboard or some other exposed surface in the hopes that the roach will come out of hiding and stand on that treated surface later is pretty optimistic. Treating exposed surfaces also increases the chances that people or pets will also contact the insecticide, or that food contamination could occur. Putting the material directly into the cracks, crevices, and voids where the roaches hide protects the active ingredient from being removed by washing, protects it from UV light, removes it from human or food exposure, and again, increases the contact time by the pest.
Where you hope for true and legal crack-and-crevice treatments you want to have none of the spray material dribbling or running out of that crevice, and water-base sprays are hard to contain in this manner. The water just too easily flows back out or splashes back from a shallow crevice, and the water takes too long to evaporate. Where a product Label MANDATES "crack and crevice only" applications this would be an illegal application properly called "spot treating" if it runs out onto exposed surfaces. Aerosols use solvents and diluents that evaporate rapidly, and are easier to retain in the crevices. So, many of the active ingredients in aerosols do give that contact kill, either on contact at the moment of the application or later when the roach rests on the treated surface.
Baits are excellent for German roaches, and gel baits still prove to be good choices. These should be incorporated into the overall treatment program. But, German roaches prefer to feed in seclusion if possible, so gel baits should never be applied out in the open on counters or other surfaces. They should be placed as "pea-sized" spots directly into crevices or gaps or small voids, taking advantage of the roach's preferencees. But, granular and dust baits also work when you can apply them into voids or use them in stations, and offering a variety of baits in a variety of formulations increases the odds that the roaches will accept some bait.
View past Ask Mr. Pest Control questions.
