Wind dispersal of the winter moth larvae Operophtera brumata L. (Lep., Geometridae) and its relevance to control measures

Oslo

1971

S. 103-105

2 Abb., 7 Lit. Ang.

Bandaufführung

9978S

136224

Extensive wind dispersal of young Operophtera brumata L. larvae took place during the spring 1967 in western Norway. Spider webs and sticky vertical traps were used in catching air-borne larvae. The dispersal, closely correlated to the temperature, was abundant even at very low wind velocities. Some days more than 30 larvae per qm were captured about 50 m from the infestation source. The expansion of the outbreak areas and heavy reinfestations in sprayed orchards indicated that numerous winter moth larvae were dispersed by wind for several hundred meters. This interfered strongly with the population development and the control measures in the orchards.