I've never tried it, but I've had several emails
over the past few years on the many uses of Bounce fabric softener, one of which
is a mosquito repellant. Supposed to tuck a sheet in your back pocket to keep
the little buggers away. Might be worth a try. Wasn't there a ridecamp post
recently about someone who went to a gymkhana or rodeo with fabric softener
sheets tied on them & their horse?