The adult vial test (AVT) developed for use with Heliothis spp. (Plapp et al., 1987) was successfully adapted to adult lygus bugs. The susceptibility of different populations of lygus to a given pyrethroid varied considerably depending on location. Two pyrethroids (bifenthrin and cypermethrin) were tested and the technique was suitable for both of them. The procedure can be done in "field" locations; treated vials, CO₂, and a few minimal tools are required. Results are read three hours after the insects are placed in the vials.