Field efficacy of the entomopathogenic nematode Steinernema feltiae against the Mediterranean flat-headed rootborer Capnodis tenebrionis

The Mediterranean flat-headed rootborer, Capnodis tenebrionis (L.) (Coleoptera: Buprestidae), is an economically important pest of stone fruit and seed fruit in Mediterranean areas. The potential control of the entomopathogenic nematode Steinernema feltiae (Filipjev) (strain Bpa), isolated from a dead C. tenebrionis larva, was tested in a cherry tree orchard in Ullastrell, Barcelona (Spain). Nematode infective juveniles (IJs) were applied by drench and injection. In both the treatments, a rate of 1 million IJs was applied per tree every week during 4 or 8 weeks, with a total dose of 4 x 10(6) IJs/tree and 8 x 10(6) IJs/tree. Number, stage and localization of insects in each tree trunk were recorded. In both the experiments, S. feltiae significantly reduced the population of C. tenebrionis providing control ranging from 88.3% to 97%. No significant differences were recorded between the different treatments. Persistence of nematodes was recorded until 6 weeks after application. Results indicate that the application of S. feltiae (Bpa) provides adequate control of C. tenebrionis in cherry trees.