Keiferia lycopersicella (Walsingham), has been a sporadic and occasionally a devastating pest of field tomatoes in northern California since it was detected there in 1960. It is uncertain that the pest is established in the area, and studies in 1966 strongly indicated that transplants from southern California were responsible for infestations that year. Preliminary studies indicated that under sheltered conditions the insect may have the potential to survive the winter in northern California when infested plants are left undisturbed in the field after harvest.