Self-dissemination of entomopathogenic fungus Beauveria pseudobassiana for biological control of Pine Wood Nematode vector Monochamus galloprovincialis

Pine Wood Nematode Bursaphelenchus xylophilus causes Pine Wilt Disease (PWD), resulting in widespread tree mortality. This quarantine organism is necessarily vectored by long horn Mono​chamus spp. beetles.  PWD management through control of the insect vectors has been proposed. Recently, the high potential of entomopathogenic fungus Beauveria pseudobassiana for the biological control of M. galloprovincialis, the only known vector of the disease in Europe, has been shown.

Several experiments were carried out aimed to develop a practical method to spread this biological control agent within the beetle population by self-dissemination tactics. Multiple funnel trap collection cups were provided with screened bottoms to effectively reduce by-catch of non-targeted beetles by 73%. Two self-release devices attached to the trap collection cups were field tested and resulted 100% effective in allowing escape of trapped M. galloprovincialis adults.  These devices were further developed to serve for the self-infection purpose. Two B. peudobassiana concentrations, [10⁹] and [10¹⁰] conidia/g in talc powder, were assayed in two self-infection devices in the laboratory. Complete mortality occurred after 9-10 days and 15-19 days for each dosage respectively. Survival time averaged was 6,2 days and 10,2 days for the high and low dosage respectively.  Further studies testing horizontal transmission of self-infected beetles would extend these results.