Nosema meligethiI. & R. (Microsporida) in populations ofmeligethesspp. in Europe

Abstract

Samples of rape blossom beetles, Meligethes spp., from 12 countries in Eastern and Western Europe were inspected for the occurrence of Nosema meligethi I. &R. infection. From most countries about a dozen samples and a few hundred beetles were inspected. A total of 13 910 individual beetles were checked under a compound microscope, and of these, 561 were found to be infected (4.03%). Despe careful examination, infection was not detectable in samples from the UK (1039 beetles inspected), Germany (694), Sweden (489), or Swzerland (280). One infected beetle was found among 444 beetles inspected from Austria, and one from Denmark (1/85). In contrast, the parase was found rather regularly in samples from Finland and from Eastern European countries. No obvious reason for this pattern of infection is known, but pesticide usage at or close to the sampling ses may play a role, because most samples from whichNosema was detected originated from areas where few pesticides are used. Spore size measurements were made fr...