Are we allowed to talk about controlling Brown Recluses here?

[Ceymann]

So about a decade ago I collected specimens of L. reclusa for at study at Kansas University dept of entomology. It was headed by Jamel Sandige an evolutionary biologist who, now along with Vetter is one of the recluse experts in the country.


It was basically testing different treatments efficiency in killing brown recluses.

Actual fumigation using a high concentration of sulfuryl fluoride was very effective and can rid a home of loxosceles infestation quickly but pricey.

typical sprays aren't that effective, one of the best ways is applying a silica gel dust laced with pyriethins like Drione dust, applied in nooks and crannies, under baseboards with a "puffer" tool.

From my experience, usually the highest concentration of loxosceles in a house with a breeding population will be in the attic so application there is crucial.
It requires many applications and it may take a few seasons to see a noticeable decline in their populations.


That being said, the danger or risk of living in a house with Loxosceles is blown WAY out of proportion! only a very small percentage of their bites lead to necrosis and in many of those bad cases, secondary bacterial infections are the complication that leads to trouble.
My grandmother lived in a big old house out the sticks that had a bad infestation, like glue traps would be packed full in the summertime for 40yrs into her late 90s, never a single incident.


Just my .02

 

[AphonopelmaTX]

So about a decade ago I collected specimens of L. reclusa for at study at Kansas University dept of entomology. It was headed by Jamel Sandige an evolutionary biologist who, now along with Vetter is one of the recluse experts in the country.
View attachment 397802

It was basically testing different treatments efficiency in killing brown recluses.

Actual fumigation using a high concentration of sulfuryl fluoride was very effective and can rid a home of loxosceles infestation quickly but pricey.

typical sprays aren't that effective, one of the best ways is applying a silica gel dust laced with pyriethins like Drione dust, applied in nooks and crannies, under baseboards with a "puffer" tool.

From my experience, usually the highest concentration of loxosceles in a house with a breeding population will be in the attic so application there is crucial.
It requires many applications and it may take a few seasons to see a noticeable decline in their populations.


That being said, the danger or risk of living in a house with Loxosceles is blown WAY out of proportion! only a very small percentage of their bites lead to necrosis and in many of those bad cases, secondary bacterial infections are the complication that leads to trouble.
My grandmother lived in a big old house out the sticks that had a bad infestation, like glue traps would be packed full in the summertime for 40yrs into her late 90s, never a single incident.


Just my .02

That is great information, but in a practical sense how does one obtain the chemicals and learn how to apply them safely?

 

[programmatic]

So about a decade ago I collected specimens of L. reclusa for at study at Kansas University dept of entomology. It was headed by Jamel Sandige an evolutionary biologist who, now along with Vetter is one of the recluse experts in the country.
View attachment 397802 View attachment 397803

It was basically testing different treatments efficiency in killing brown recluses.

Actual fumigation using a high concentration of sulfuryl fluoride was very effective and can rid a home of loxosceles infestation quickly but pricey.

typical sprays aren't that effective, one of the best ways is applying a silica gel dust laced with pyriethins like Drione dust, applied in nooks and crannies, under baseboards with a "puffer" tool.

From my experience, usually the highest concentration of loxosceles in a house with a breeding population will be in the attic so application there is crucial.
It requires many applications and it may take a few seasons to see a noticeable decline in their populations.


That being said, the danger or risk of living in a house with Loxosceles is blown WAY out of proportion! only a very small percentage of their bites lead to necrosis and in many of those bad cases, secondary bacterial infections are the complication that leads to trouble.
My grandmother lived in a big old house out the sticks that had a bad infestation, like glue traps would be packed full in the summertime for 40yrs into her late 90s, never a single incident.


Just my .02

Great to hear you chime in. I was doing tests as well, thus my suggestion. But important to note, these were admittedly very crude tests- not anywhere near scientific like yours. Basically, swabbing a very tiny amount of bifenthrin 7.9% diluted to 0.12% on the bottom of a piece of paper, letting it dry for a day, then coaxing a recluse to walk across it and then removing it. I was curious of the efficacy of the residual effect. It was effective within 15 minutes (observed "convulsions" of the sodium channel manipulation effects under microscope), then death.

That said, I understand it's not as simple as that and that your study was looking at a bigger picture. And I agree that dusting, preferably with something like amorphous silica dioxide combined with a waterproof pyrethroid, is probably a more effective systemic approach. I also agree with what you and everyone else is saying about the sensationalized threat by the media in general. I think we're all on the same page in that regard.

Is there anywhere I can read more about your work on this? I know there was a study with TalStar (i.e. bifenthrin) that showed no actual "repellancy" effect, which was interesting but kind of expected.

 

[dangerforceidle]

Great to hear you chime in. I was doing tests as well, thus my suggestion. But important to note, these were admittedly very crude tests- not anywhere near scientific like yours. Basically, swabbing a very tiny amount of bifenthrin 7.9% diluted to 0.12% on the bottom of a piece of paper, letting it dry for a day, then coaxing a recluse to walk across it and then removing it. I was curious of the efficacy of the residual effect. It was effective within 15 minutes (observed "convulsions" of the sodium channel manipulation effects under microscope), then death.

That said, I understand it's not as simple as that and that your study was looking at a bigger picture. And I agree that dusting, preferably with something like amorphous silica dioxide combined with a waterproof pyrethroid, is probably a more effective systemic approach. I also agree with what you and everyone else is saying about the sensationalized threat by the media in general. I think we're all on the same page in that regard.

Is there anywhere I can read more about your work on this? I know there was a study with TalStar (i.e. bifenthrin) that showed no actual "repellancy" effect, which was interesting but kind of expected.

Out of curiousity, what type of spider were you trying to control?

If your profile location is correct, you would not have brown recluse spiders in your home.

 

[programmatic]

Out of curiousity, what type of spider were you trying to control?

If your profile location is correct, you would not have brown recluse spiders in your home.

The crude testing was done on L. reclusa (was given to me specifically for this test, not found locally) as mentioned in the post. This was unrelated to control efforts for a pest issue that put me down the pyrethroid rabbit hole to begin with.

 

[Ceymann]

That is great information, but in a practical sense how does one obtain the chemicals and learn how to apply them safely?

Drione dust can be obtained on a certain DIY pest control website and is actually quite human/ pet safe compared to other insecticides, and you can buy the "puffer" tool there as well, yet its the same stuff a professional pest control specialist trained to deal with BR would use on a infestation, in addition to laying down a exterior liquid barrier product like Demon WP.

This is a pretty great video that dispells the undeserved reputation of these spiders.