Here is another reply, this is from Patricia Denke she s from the Montana state agriculture dept.
"The biggest problem is that both of the materials that interfer with various insects growing up are actually against insects only, and have limited or no efficacy against arachnids (mites). Findng the material against insects was a luck thing - people were trying to raise insects, and the insects wouldn't grow, so they tried to track down the problem. It eventually was ruled down to "paper factor", which turned out to be a material balsam fir (used to make the paper they lined the rearing cages with) made an analogue of insect juvinile hormone. This information has been used to develop the material called methoprene. There is another material that is sometimes used, called dimilan, which prevents the insect from making a new exoskeleton.
There has been little work on developing anything like them against any arachnids. I suspect part of the reason is the apparent small market, as well as the difficulty developing something with sufficient specificity"