The insect growth regulator, fenoxycarb, when applied at 0.06 kg AI/ha (0.05 lb AI/acre) as 1% sand granules was highly effective (97.5% corrected mortality) against Aedes communis, Ae. stimulans and Ae. canadensis in snowmelt pools in Massachusetts, and 100% effective against Ae. abserratus in an insectary study. No larval mortality owing to fenoxycarb treatment was observed, and most mortality occurred in the pupal stage as opposed to aborted adult emergence.