EVALUATION OF LOSS OF (-DISPARLURE FROM GYPSY-MOTH (LEPIDOPTERA, LYMANTRIIDAE) PHEROMONE DISPENSER TAPES UNDER FIELD CONDITIONS IN FLORIDA())

The residual pheromone content of laminated plastic, pheromone-dispens ing tapes impregnated with (+)-disparlure, the sex pheromone of the gy psy moth, Lymantria diapar (L.), was assessed after exposure to field conditions in Gainesville. As determined by gas chromatography, lure t apes deployed on 26 August 1991 rapidly lost pheromone during the firs t 2 months in the field. Loss of pheromone was considerably less for t he remaining 4-month exposure period (28 October 1991 to 3 March 1992) . Lure tapes at 5 locations differed slightly in their rates of pherom one loss, and traps placed on the north side of tree trunks retained m ore pheromone than traps placed on the south side. These data indicate that a pheromone lure used for monitoring gypsy moth during spring an d early summer in north Florida may lose its effectiveness rapidly and may have to be replaced more often than is currently recommmended for other regions of the country.