This line of clothing uses an EPA approved process called Insect Shield® Repellent. They use a pesticide called Permethrin for this. I assume that the Permethrin is micro-encapsulated to make it last longer. Permethrin is an irritant to ticks and fleas and will kill them if exposed long enough. Permethrin is used in some spot flea and tick medications you get for dogs and cats. Same principal except put on clothing. Permethrin is the active ingredient in many fly bombs and sprays you buy at the store. I have not tried it, but sounds interesting. You can now buy products with this process in shirts, pants and other apparel. This product will work on fleas as well. Permethrin used in Pest Control will effect quite a large variety of insects, so it is possible that it may help keep other insects off as well, but am not certain about this.
This link provides more facts for those interested:
Insect Shield® Repellent
http://www.insectshi...ology/faqs.aspx
Regarding tick populations, they have done studies to try and discover what increases their populations. From the studies they have found correlations between early springs where temperatures above 65 degrees activate ticks to reproduce sooner which results in higher populations in the summer. They have found droughts reduce the number of tick nymphs (babies) that survive & perhaps reduce rodent populations. Extreme winter snow/cold reduces rodent populations as well & tick populations. Rodents carry more ticks by far than all the other animals put together, simply because of their numbers, so anything that effects rodent populations will also effect tick populations. Fleas follow suit.
Rocky Mounted spotted Fever cases in the US have remained fairly stable. The Lyme tick disease reports are on the rise, perhaps doctors being able to now diagnosis this disease better, has something to do with this. Not that many years ago, doctors had no idea what it was. HTH.
Edited by HighlandHunter, 29 January 2012 - 11:56 PM.