A SEQUENTIAL DECISION PLAN FOR MANAGEMENT OF THE ALFALFA BLOTCH LEAFMINER, AGROMYZA FRONTELLA (DIPTERA: AGROMYZIDAE)

Abstract

A sequential decision plan, based on the negative binomial distribution and providing for two infestation classes, has been derived for use in management of the alfalfa blotch leafminer, Agromyza frontella (Rond.), in southern Ontario. It utilizes counts of the eggs in leaflets of alfalfa, and in economic situations will provide growers with sufficient lead time to consider alternative action strategies. An appraisal of the plan by field scouts showed that it rated the infestation status of the leafminer correctly in 48 of 51 cases. Sampling time averaged 25 min per scout per field.