Over the weekend we found a rather large spider in the house, of a type we had never seen. Someone had the bright idea of trapping it so as to show it around; the only thing handy was a nearly empty bottle of ground black pepper. After emptying out the bottle (but not rinsing it) we coaxed said spider in. Within 10 minutes it was clearly in great difficulty, and about two hours later it was gone to that great web in the sky.
So, does anyone know if there’s something in black pepper that works as an insecticide? Or did the spider just suffocate on the fine remains of ground pepper?
The good thing about a pepper jar (from my perspective) was the tight-fitting plastic cap with large holes in it that you normally shake the pepper through… if it suffocated, it wasn’t for lack of an air source.
It occurred to me later that if the pepper wasn’t poisonous, maybe the peppery powder left in the jar clogged the little air holes (scientific term) that spiders normally breathe through.Spiders not normally being something that fascinate rather than scare the bejeesus out of me, I have no idea whether that might even be possible.
[ol]
[li]What makes pepper (black ground as well as jalapeno) peppery (spicy and/or hot) is acidic oils.[/li][li]Oil tends to stick to surfaces.[/li][li]Spiders and other arthopods get their air through tiny holes in their exoskeleton.[/li][/ol]
So, my WAG: oil vapor from the pepper condensed on the spider, clogging his breathing holes, and suffocated him.
Since we’re talking about killing spiders (which are not insects!), you should ask if pepper is an arachnicide, not if it’s an insecticide. Many chemicals that act as insecticides also act as arachnicides, of course.
Respiration in spiders: Air is passed through a small hole (called a pneumostome) on the underside of the spider into the book-lung (a/k/a lung-book) which is a membrane where gases are exchanged. The name derives from the shape of the folded membrane, which looks like the pages of a book.
In one of the Patrick O’Brian books (Wine Dark Sea, I think), Stephen Maturin is in great distress because he has run out of pepper and moths are eating some of his specimens. So yes, assuming that P O’B did his research (and that’s a very safe assumption), pepper was once used as a sort of insecticide/preservative.
Also reasoning logically, the reason that plants develop blistering substances like pepper is to keep away predators.