NATURAL CONTROL OF TENTIFORM LEAFMINER PHYLLONORYCTER BLANCARDELLA IN DUTCH APPLE ORCHARDS.

Some observations in recent years are presented to illustrate the basic pest status of the tentiform leafminer Phyllonorycter blancardella in Dutch apple orchards.
They show that the densities of this species permanently stay at an innoxious level in non-treated orchards, corroborating similar experiences in some other countries, like Hungary and Canada.

Comparison of the adult numbers captured during successive generations in suction or pheromone traps with the levels of larval parasitism suggests that parasitism is the dominatig mortality factor during the 1st larval generation, but less so during overwintering.
The parasitoid species involved hardly differ from those observed elsewhere in Europe.
Pesticide side effects should be avoided on the more abundant ones during their first flight around blossom time.

International Conference on Integrated Fruit Production

Leo H.M. Blommers, F. W.N.M. Vaal

https://doi.org/10.17660/ActaHortic.1996.422.37