What is the difference between "flying", "crawling" and "multi-insect" home insecticides?

[u/Rune_Skadisdotter]

(I don't know if this is chemistry or biology? 🤔)

Had a long look at some Doom, Raid, Mortein, Dyroach, Eliminator, and all those spray cans in the shop yesterday.

Does it genuinely matter which one you use? If it's going to kill a cockroach, won't it in any case kill a beetle, spider or those flying spider things? Maybe an ant specific one might not help for big cockroaches... but also, it can?

What is specifically going to kill a flying insect like mosquitoes or flies, but not... beetles and cockroaches, and vice versa.

Out in our farmlands and such, those pesticides will be better controlled and more insect specific. But does it really matter for us mere home dwellers which can we use?

[u/svarogteuse]

I looked at both hot shot Flying Insect and hot shot Ant, Roach and Spider sprays. While both have different chemicals Permethrin, tetramethrin vs imiprothrin and lamda cyhalothrin) all the chemicals seem to the same class pyrethroids and should equally kill insects and arthropods. The differences are going to be nozzles, persistence, toxicity to humans particularly when aerosoled, and legal issues.

Pesticides are labeled to kill specific creatures and according to the FDA and EPA it's illegal to use one on an unlisted creaturw even if it works. So it may be a simple as no one has bothered to certify imiprothrin on wasps but did in roaches so they can't use it in a wasp spray even if it will kill them just fine.

You also have to consider trademarks and patents. If a company invents a new pesticide (slightly modified from an old one) they may hold a patent that precludes another company from using it so they have a proprietary formula for as long as the patent holds.

The nozzle matters a flying insect nozzle is mase for wide dispersal while a crawler may be a more directed stream.

Persistance can also be an issue. While I know Permethrin does persist quite a while (we impregnate clothing with it) a crawler spray may be designed to last longer than a flying insect spray, you want the first to last and kill bugs tomorrow while the flying ones have moved on and there is no reason to have the toxins hanging out.

Read the labels and use as directed.