I think its to late now for them to do any serious damage ... also using pyrethrum will prolly ruin ur smoke, the best thing i can think of right now is to use some insecticide soap wash but be very carefull with it cause u may get mold in ur buds ... hopefully some more experienced growers or growers that have had the same prob that u do will stop by and give u a more clear idea of what to do ... good luck