One line of defense against biting insects and potential disease-carrying insects is clothing treated with the insecticide permethrin. These clothes are increasingly popular with birders and anyone who spends time outdoors, including backyard naturalists and gardeners.

Consumer Reports tested insect-repellent shirts from L.L. Bean and ExOfficio. Not surprisingly, none of the shirts were foolproof in repelling insects. Actually, none were as effective as an ordinary shirt sprayed with DEET. But it’s important to note that the manufacturers emphasize using an insect repellant along with the insect repellent clothing.

See the test results here https://www.consumerreports.org/insect-repellents/permethrin-treated-clothing-mosquito-bites/