Release rates for pine sawfly pheromones from two types of dispensers and phenology of Neodiprion sertifer

Comparisons of release rates, duration in the field, and catch efficiency o f polyethylene and cotton roll dispensers for the sex pheromones of sawflie s (Hymenoptera: Diprionidae) were conducted. The release rates of the neodi prion sertifer(Geoffr.) and Diprion pini (L.) sex pheromones, the acetates of pentadecanol and (2S,3S,7S)-3,7-dimethyl (2S,3R,7R)-3,7-dimethyl--tridec anol from polyethylene dispensers were measured at different temperatures i n the laboratory. The release rates for the substances depended on both the temperature and initial load in the vials. The catch from cotton rolls bai ted with 100 mug of the acetate or propionate of 3,7-dimethyl-2-pentadecano l was compared to the catch from regularly renewed cotton rolls baited with 10 mug of the same acetate. The catch was higher for the 100-mug cotton ro lls for, at most, 45 days, and there was no significant difference in catch between the acetate and the propionate. The catch in traps baited with pol yethylene or cotton roll dispensers loaded with the acetate of 3,7-dimethyl -2-pentadecanol was compared and showed that cotton roll traps mirrored the decreasing release of the substance rather than the actual Right activity. The length of the flight period of N. sertifer in Sweden, the Czech Republ ic, Italy, and Greece did not exceed 100 days in any of the countries. By a djusting the initial pheromone load of the polyethylene vials to the expect ed temperatures, it should be possible to get a constant and sufficiently h igh release rate during the entire flight period.