Abstract
We investigated prevalence of leafminer flies on okra cultivated in greenhouse in Ibusuki City, Kagoshima Prefecture, Japan. Liriomyza trifolii （Burgess） was the only leafminer pest found on okra. The numbers of leafminers in greenhouses where commercially produced parasitoid wasps, Neochrisocharis formosa （Westwood） were released at a density of 50 individuals/1,000m2, did not differ significantly from those in greenhouses where insecticides were sprayed. These results suggested that biological control using parasitoids could be substituted for insecticides. However, as N. formosa which seemed to be derived from indigenous populations also occurred in greenhouses with insecticide applications, we considered that the effects of biological control in this study were obtained by the complex parasitoids populations including the indigenous ones. Since the indigenous parasitoids of leafminers have been known to be effective natural enemies, we also need to investigate the probability of conservation biological control on leafminers using indigenous parasitoids’populations for more developmental control strategies.
