Abstract Experimental plots measuring 25 ft X 25 ft were established in a 2-yrold field of alfalfa ‘Pioneer 5333’ alfalfa in the vegetative state located in Ithaca, N.Y. Soils were silt loam. Five treatments and one untreated check were replicated 4 times in a RCB design. Treatments were applied on 1 Jun with a CO2 pressurized ATV-mounted, eight nozzle spray boom which spanned 12 ft. The sprayer delivered 32 gal/acre at 60 psi and an ATV speed of 3.5 mi/hr. AW density was evaluated 1 d pretreatment and 7 and 14 DAT by collecting 10 stems per plot and counting the total number of larvae collected per plot. Damage incidence for each 10 stem sample was recorded. On 4 DAT, AW density was evaluated only in the check plots. Data for all plot samplings were expressed as mean AW/stem.