Diseases of insects of medical importance in Europe.

The biological control of insects carrying human diseases was first attempted many years ago, but the results were disappointing owing to the insufficiency of information on the ecology and pathology of such insects at the time. In recent years, however, increased knowledge of insect pathology and ecology and the development of insecticide-resistance have led to a revival of interest in this method of vector control. Most of the recent published work on this subject relates to findings in North America; comparatively little information has hitherto been available in respect of Europe. This paper, which is based on a survey of the literature and on the author's own experience, presents the results of research on diseases of insects of medical importance in Europe. Infection with viruses, rickettsiae, bacteria, fungi, protozoa and nematodes are discussed and suggested lines for future European research on biological control are put forward.