Articles
ECOLOGICAL STUDIES AND PROPSECTS FOR CLASSICAL BIOLOGICAL CONTROL OF APPLE PESTS IN EUROPE AND ELSEWHERE
IOBC/WPRS working groups were instrumental in developing protocols to test the side effects of pesticides on non-target and beneficial organisms and guidelines for integrated production of pome fruits in Europe.
Some major natural control agents such as predatory mites and anthocorids received due consideration, and some biological control agents were deliberately used to alleviate specific pest problems (e.g. Aphelinus mali against apple woolly aphid and Prospaltella perniciosi against San José scale). In spite of all past efforts, the effect of natural control and the use of classical biological control agents has been largely disregarded, a heritage from the days when a zero percent tolerance level was advocated and accepted as a standard that was prohibitive to the use of biocontrol agents.
However, problems from increasing resistance to a decreasing number of registered pesticides warrant a novel approach.
We now need to better understand and compare the ecology of natural control agents.
Key issues would be investigations on the diversity and abundance of natural enemies in different regions and in relation to orchard management, varieties etc. in order to enhance opportunities for biological control.
The likely area of origin of apple and some major pests such as codling moth is in central and eastern Asia where natural enemy complexes are known to be different from those in western Europe.
As the evolutionary centres of pests are known to have the greatest diversity of co-evolved natural enemies, these must not be ignored as potential sources of biocontrol agents to be used elsewhere.