Jul 3, 2011 – Creepy Crawlies Above
QUESTION:
I am dealing with spiders in the attic! Would BP-100 work? Could you please explain how BP-100 works, how long it will last, and is it a good product to use?
ANSWER:
Let's deal with the residual question first, and this one is very subjective. You will find answers such as it deteriorates within minutes, maybe within a couple of hours, or it lasts for days. My personal opinion is that pyrethrum applied where it is exposed to light (sunlight or fluorescent) will degrade within 2 to 3 hours. If applied into a dark and relatively cool wall void I have heard it might last a few day. If applied into a dark but HOT attic we again are probably looking at no more than a few hours. Regardless of the length of time the molecule remains intact, pyrethrum should be considered as effective only if it can contact the arthropod while wet. This might be droplets of a fog or mist landing on the bugs or the bug crawling on the surface that still is wet from the spray landing on it.
One way to lengthen the residual is to use a microencapsulated formulation like Microcare CS. The active ingredient (the pyrethrum) is contained within those millions of microscopic capsules, and this protects it somewhat from environmental degradation until it slowly oozes out of the capsule. This might get you a couple of weeks of residual and also be effective once dried on the surface. Better for spiders are the synthetic pyrethroids, and most of them are not labeled for use as a space spray, which seems to be what you are looking for. They would need to be applied directly onto surfaces the spiders will crawl on, and this means crawling around in the attic. A possible option though would be a total-release aerosol such as Pro-Control Plus T/R aerosol with synergized pyrethrum AND cyfluthrin (a pyrethroid). This is labeled for attics and for spiders. You also could consider the use of a contact dust such as Drione or MotherEarth D. These are desiccants that last forever, are extremely low in hazard to people, and kill by causing dehydration of the arthropod when they scratch into the exoskeleton.
How does pyrethrum work, and BP-100 is a 1% pyrethrum with 5% dual synergists. The synergists are there to enhance the ability of the pyrethrum to kill arthropods by blocking their ability to metabolize the pyrethrum before they are killed by it. The specific mechanism by which pyrethrum actually causes the death of an arthropod goes like this, and it sounds a bit technical. Pyrethrum is an "Axonic Poison B", which also called a "GABA-gated Sodium Channel Blocker". Within an animal's nervous system the nerve impulse is carried along through axons, and several "channels" in that axon are involved. In the case of pyrethrum it attaches to a protein in this sodium channel that normally would halt a nerve impulse from continuing. Binding to this important protein results in continuous firing of that nerve cell, and thus the insect cannot control it, organs are over-excited, and in a short time the organs fail and the insect dies.
This is the very same manner that some other insecticide families work on the nervous system, including the Synthetic Pyrethroids and some chlorinated hydrocarbons such as the old DDT. In general, pyrethrum is an excellent active ingredient with limitation on its use. It works only on exposed bugs and usually cannot penetrate under or into hiding places, and since it degrades so rapidly it cannot be counted on for residual results.
View past Ask Mr. Pest Control questions.
I am dealing with spiders in the attic! Would BP-100 work? Could you please explain how BP-100 works, how long it will last, and is it a good product to use?
ANSWER:
Let's deal with the residual question first, and this one is very subjective. You will find answers such as it deteriorates within minutes, maybe within a couple of hours, or it lasts for days. My personal opinion is that pyrethrum applied where it is exposed to light (sunlight or fluorescent) will degrade within 2 to 3 hours. If applied into a dark and relatively cool wall void I have heard it might last a few day. If applied into a dark but HOT attic we again are probably looking at no more than a few hours. Regardless of the length of time the molecule remains intact, pyrethrum should be considered as effective only if it can contact the arthropod while wet. This might be droplets of a fog or mist landing on the bugs or the bug crawling on the surface that still is wet from the spray landing on it.
One way to lengthen the residual is to use a microencapsulated formulation like Microcare CS. The active ingredient (the pyrethrum) is contained within those millions of microscopic capsules, and this protects it somewhat from environmental degradation until it slowly oozes out of the capsule. This might get you a couple of weeks of residual and also be effective once dried on the surface. Better for spiders are the synthetic pyrethroids, and most of them are not labeled for use as a space spray, which seems to be what you are looking for. They would need to be applied directly onto surfaces the spiders will crawl on, and this means crawling around in the attic. A possible option though would be a total-release aerosol such as Pro-Control Plus T/R aerosol with synergized pyrethrum AND cyfluthrin (a pyrethroid). This is labeled for attics and for spiders. You also could consider the use of a contact dust such as Drione or MotherEarth D. These are desiccants that last forever, are extremely low in hazard to people, and kill by causing dehydration of the arthropod when they scratch into the exoskeleton.
How does pyrethrum work, and BP-100 is a 1% pyrethrum with 5% dual synergists. The synergists are there to enhance the ability of the pyrethrum to kill arthropods by blocking their ability to metabolize the pyrethrum before they are killed by it. The specific mechanism by which pyrethrum actually causes the death of an arthropod goes like this, and it sounds a bit technical. Pyrethrum is an "Axonic Poison B", which also called a "GABA-gated Sodium Channel Blocker". Within an animal's nervous system the nerve impulse is carried along through axons, and several "channels" in that axon are involved. In the case of pyrethrum it attaches to a protein in this sodium channel that normally would halt a nerve impulse from continuing. Binding to this important protein results in continuous firing of that nerve cell, and thus the insect cannot control it, organs are over-excited, and in a short time the organs fail and the insect dies.
This is the very same manner that some other insecticide families work on the nervous system, including the Synthetic Pyrethroids and some chlorinated hydrocarbons such as the old DDT. In general, pyrethrum is an excellent active ingredient with limitation on its use. It works only on exposed bugs and usually cannot penetrate under or into hiding places, and since it degrades so rapidly it cannot be counted on for residual results.
View past Ask Mr. Pest Control questions.
