INVESTIGATIONS ON DEMAND FOR BIOLOGICAL-CONTROL OF OTIORHYNCHUS SPP AND COST-STRUCTURE OF PRODUCTION METHODS FOR ENTOMOPATHOGENIC NEMATODES (HETERORHABDITIS)

A survey of eighty tree-nurseries in the Federal States of Schleswig-Holstein and Lower-Saxony, which was carried out during summer 1992, delivered basic data about the demand for entomopathogenic nematodes for biological control of Otiorhynchus spp.. These data serve as basic for the estimation of the production costs and the cost structure of the production methods for entomopathogenic nematodes of the genus Heterorhabditis. The results confirm that Otiorhynchus spp. cause dominating plant disease problems in tree-nurseries. Chemical control methods do not lead to sufficient results. Biological control methods, which are more effectively, have not often been used by the farmers at the time of the survey. As main reasons could be detected: an insufficient availability of entomopathogenic nematodes with high quality-standards, comparatively high costs per unit of nematodes and the low standard of information about the application methods for nematodes in the nurseries. In contrast to the traditional production method for heterorhabditide nematodes, lower production costs and prices, and higher quality-standards are expected by a new, innovative technology for producing nematodes, developed by the Institute for Phytopathology of the University of Kiel. The economic particularities of this innovative technology are discussed.