http://straightdope.com/mailbag/mrepellent.html
While the ever popular Frontline/Frontline Plus lines do not repel mosquitoes, other brands actually do. K9 Advantix and Biospot, for example, use permethrin as a mosquito repellent.
Welcome to the Straight Dope Message Boards, thisrobin, glad to have you with us. And thanks for providing a link to the Staff Report.
Doug, who wrote the Staff Report, is a professional entomologist, and he knows whereof he speaks. I will ask him to stop by to comment.
I’m certain Doug knows far more about insects than I do, and given his profession, I’ll bet he likes them more than I do too. No disrespect was intended. But the products I listed and others make this claim:
“Repels mosquitoes, carriers of West Nile Virus, and ticks that may carry Lyme Disease.”
I’m just not certain Doug wasn’t generalizing his answer to the more prevalent brand in dog flea/tick protection (Frontline). If he wasn’t, and no brand of flea/tick protection can legitimately make that claim… well, I imagine the lawsuit line will start queuing up soon enough.
Nice name choice, btw… “Philadelphia Story” is a great movie.
It’s always been very annoying to me that they used my name in that movie.
I would just point out that while Biospot uses permethrin, that is all it uses. Permethrin in a spot-on applicator is an attempt (in my educated opinion) to fool the consumer. Permethrin is best applied as a spray or shampoo. When Frontline(fipronil) and Advantage(imidacloprid) were introduced there efficacy and safety were amazing. Other companies (hello Hartz) quickly came out with applicators that looked similar to the ones used by Advantage/Frontline.
Sorry about that. In my hurry to jump onto my soapbox, I didn’t proofread. 
Also, let me mention that Advantix uses the permethrin that is added to the imidacloprid to make the product have some efficacy against ticks.
There is NOTHING I’m aware of that actually repels mosquitoes. There are some chemicals (DEET, nepetalactone, etc.) that interfere with the females’ ability to detect prey, but that is not the same as repelling them. Permethrin KILLS mosquitoes, as it does other arthropods. Claiming that it repels them is playing fast and loose with the definition of the word “repel”. It’s the exact same sort of trick of phrasing used in advertising household “deodorants” - they do not actually remove existing odors, but act by blocking your ability to SMELL the other odors. Calling that sort of chemical a “deodorizer” is the same as calling DEET a “repellent”. Yes, a person or animal that has permethrin on them will not be bitten by mosquitoes as often as one that has nothing; and, as far as product liability and advertising laws, that’s all it takes for a product to be able to claim that it’s a “repellent” - but there is nothing in that product labeling that tells you WHY one is not being bitten as often (in that case, it’s because the skeeters are dropping dead).
Peace,
Great answer, Doug. It is my understanding that the reason product labeling is lacking in situations like this is because the EPA regulates topical pesticides, not the FDA.
But Doug (nice name, by the way! 
), isn’t the real point of the OP that your claim in the article was that mosquitos aren’t dealt with by the products in question, and in fact, several of them do deal with mosquitos? If I’m concerned about mosquitos and my pet, it certainly would be important to know that some products readily available at least attempt to interfere with that relationship, much as Off! does as regards my own, mosquito-tasty body?
Perhaps a slight amendment to the article could be made, clarifying?
You’re saying that the reason I’m not getting bitten is that the mosquitos are in fact dropping dead in the putative 0.25 second interval between landing and proboscing? And that mosquitos can in no way smell a fatal concentration of toxic compound that is easily detected by the human nose? This just seems really, really unlikely; I’d like to see a reputable source that backs up your claims, or the original claims explained in a way that makes them a bit easier to swallow. Like are we in fact emanating a cloud’o’death that kills mosquitos before they even touch us?
How do you think Lydia the tattooed lady feels?
Please excuse my ignorance. I didn’t realize you predated the screenplay. I had not guessed you were 67+ years old.
Actually, methoprene IGR is also an active ingredient in their “spot on” flea and tick control.
Right. And methoprene can be applied in a variety of ways (shampoo, dip, spray) and over time can lead to a decrease in the flea population by affecting reproduction of the parasites. Methoprene in no way repels or kills fleas, so in a flea free dog it will not affect the number of flea bites the animal receives when entering an environment with fleas (like your backyard). 
ETA: also, see the OP title. Methoprene is definitely not a repellent.