Equilibre actuel entre Hoplochelus marginalis (Col., melolonthinae), ravageur de la canne a sucre et son pathogene antagoniste: Beauveria brongniartii (Deuteromycotina, hyphomycetes).

摘要

The introduction in 1988 of the entomopathogenic fungus Beauveria brongniartii in Reunion caused a gradual decline in the population of the white grub Hoplochelus marginalis to below its economic injury level. However, with the occurrence of localised outbreaks of the pest, further studies were initiated by Research and Development institutions. A first island wide survey, conducted in 2001, allowed to establish the current level of equilibrium between the pest and the pathogen. Although the pest density was below economic injury levels in 15 towns, there is a need to remain vigilant since level of larval mycosis was between 20 and 30 percent in previously infested areas. A tenfold increase in the population of the pest, at low levels, was observedin St Paul compared to the population of 1996. In St Pierre and Saint Joseph, at certain altitudes grub populations higher than the economic injury levels were observed.