A few years ago I hired an exterminator to deal with spiders in my house. The tech came out with spray and powder. I asked her what we were doing wrong–we’d been spraying. She said what we needed was a certain chemical. When I showed her the spider-killer we were using, she seemed surprised that it contained that chemical, but in a much lower concentration, apparently, than her stuff.
Then I could never find that brand of spiderkiller again, and I’ve forgotten the name of the stuff.
So, question #1: What was that stuff? If it matters, I don’t remember what kind of spiders I had. Nonpoisonous. There were a lot of them, though.
And question #2: Are professional killers allowed to have different chemicals than ordinary people, and if not, then where do I get these super bug-killers?
I cannot help you, but I *will *tell you that if your home is successfully supporting spiders, it’s because they’re finding enough bugs to eat. Never get rid of spiders; they are your bug eatin’ friends.
Also, a nitpick, spiders inject venom when biting. Venom injected by critters through bites and stings is called venom and has toxic effects on their usual prey and sometimes others, such as us.
Poison is toxicity that affects those that touch the poisonous part or ingest the poisonous stuff. There are froggies that if you touch or eat them will harm you.
She was talking rubbish. Pretty much any over-the-counter insecticide will kill spiders on contact.
Impossible to say. Permethrin, Cypermethin and Deltamethirn are probably the most common insecticides used for treating spiders.
That depends on your local legislation. Very few substances are restricted at a Federal level but each state and quite a few individual counties/cities have pesticide licencing requirements. However those restrictions are all for fairly nasty stuff, organophosphates at the least, and not the type of stuff you’d want to use to treat domestic spiders.
There’s nothing super about them. The most effective spider treatments are the same ingredients found in the pestcides from your local hardware store. Heck, Cypermethrin is found in a lot of aerosols.
There are a few things you need to know about controlling spiders:
Residual control is very difficult. For insects you can just spray the floors and walls and any animal crawling over the pesticide for the next six months will drop dead. Spiders walk on their toenails, they don’t groom much and they don’t move much anyway, so residual control is very difficult. You can get some residual effect if you use a dust or a wettable powder. These leave relatively large lumps of pesticide behind, rather than the thin fill left by emulsion and suspensions so they are picked up more readily. But they also leave visible dust behind so they are often unsightly.
You basically have to wet a spider directly to kill it. That make sit very hard to do an effective job because their webs are themselves water resistant and they often live in cracks, not in they webs themselves.
To get the best chance of wetting a spider that you can’t see you need to create an aerosol of some sort and let it drift around. That means either a high pressure sprayer, a commercial mister or a dust applicator.
4)The best way to control spiders is often to remove their food. Assuming you have insect screens then if you treat your house thoroughly with a residual insecticide you will remove the ants and cockroachs the spiders are feeding on.
You can get reasonable control using standard equipment by doing a thorough job. Go down to your local hardware store and buy some Deltamethrin or Permethrin insecticide, preferably a WP formulation. I have yet to see a hardware store that doesn’t sell these. Buy a pump up garden sprayer. Set the jet to a fine mist. Wet any spiders that you can see, and if you see a web spray into any cracks nearby. Then spray all the skirting boards and the frames of all doors and windows. You are trying to make it impossible for an ant or cockroach to enter our house or walk from one room to another without crossing the area that you have sprayed.
As usual read the saftey direction and use all recommended PPE.
The only other bugs I have seen besides spiders are one (1) cricket, one (1) katydid–both of these were dealt with by my cats, who seemed to enjoy the process–and one fly per day. I will be happy to swat this daily fly myself.
Of course you have now raised the possibility that in addition to visible spiders I have hidden bugs. I should have bombed the place before I moved in.
I’m not sure where this myth came from, but it’s not true. It’s been done to death
on these boards.
A poisonous creature is one which is capable of poisoning. The means of application of that poison is irrelevant. A spider is definitely poisonous.
A venomous creature is one that produces a venom. By some definitions a venom needs to be injected, but that is by no means mandatory. It is perfectly correct to refer to the toad, ugly and venomous, despite the fact that toads have neither teeth nor nails with which they could inject their venom.
Thanks, Blake, for the info. Sounds like a plan, although I am now thoroughly freaked out. Since I have seen zero evidence of roaches or ants, it makes me worried that I have a lot of unseen spiders.
I should note that poisonous, venomous, or neither, spiders creep me the hell out, and I will freak out if I see even a small one, and the ones coming in now that it’s getting cold are not small. I don’t think about the poison or venom delivery system because I’m already in a little quivering ball in another room somewhere.
Spiders are tough to kill. As mentioned above, unless you manage to spray the spider directly, the spiders will probably live through any residual insecticide.
Without calling in the pros (and in truth, even most professional pest control services don’t guarantee against spiders), about the only effective thing you can do is fogging/fumigating. Follow the directions very carefully and be thorough; you don’t want insecticide residue on any food preparation surfaces, dishes, bedding, or anything of the like. It may take more than one fogger/fumigator to treat your entire house. Prepare the house as directed (turn off fans and AC, close rooms you don’t want fumigated, cover anything you don’t want poison on, open cabinets under sinks and such that you want to fumigate, etc.), set off your fogger(s), and quickly head out. Go to the movies for a few hours or something. When you get home, open doors and windows and let the place air out for a while; most foggers recommend 30 minutes. Then, give a thorough wipe-down to anything you plan on touching or eating off of.
After that, you’ll probably find dead bugs lying around for the next few days. In my experience, a thorough fogging will keep the bugs away for two months at the maximum, usually a month, a week if you’re unlucky. But, these will be new interlopers; foggers are very thorough, and the fog should get into every nook and cranny where your non-paying tenants reside.
In general, spider control is pretty much like regular insect control. Don’t leave standing water around. Clean up food spills that may attract insects. Vacuum regularly. That sort of thing. As said above, if you drive off your other insects, the spiders won’t have anything to eat, and they’ll have to either leave or starve.
