A Beauveria bassiana strain naturally parasitizing the bee predator Vespa velutina in France

Abstract

Vespa velutina is a hornet predator of bees that was accidentally introduced in Europe from China in 2004. Since its arrival, it expanded through Europe, impacting both biodiversity and beekeeping. As there are currently no biological alternatives to chemical treatment of V. velutina nests, we need more studies on the development of potential biological control methods. We present here a further description of an indigenous strain of entomopathogenic fungi, Beauveria bassiana that was discovered naturally parasitizing a foundresses of V. velutina in France. The genus was identified by its macro and micro morphological characteristics and the specie by molecular techniques. It growing preferences were described according temperature conditions, and the potential in using such entomopathogens as a biological control agent against V. velutina was also discussed here, first at least to replace currently occurring direct chemical treatments, and then potentially to be integrated in future Trojan horse strategies.

Entomopathogenic Fungi for Pests and Predators Control in Beekeeping

“…An impulse to continue on this path was given by the discovery in Europe of the Asian hornet, V. velutina [130]. In 2006, Merino et al [131] studied the pathogenicity of 29 isolates of M. anisopliae and 30 of B. bassiana, on workers and males of Vespula germanica. Evaluation was performed by administering doses of 1 × 10 8 conidia/mL of each isolate, in sugary liquid bait.…”

“…Evaluation was performed by administering doses of 1 × 10 8 conidia/mL of each isolate, in sugary liquid bait. Mortality and sporulation of the isolates of B. bassiana Qu-B941 and Qu-B933 were significantly higher, reaching percentages of 90% and 97%, respectively, for Qu-B941 and Qu-B933, with the highest concentration of inoculum [131]. Three years later, Brownbridge et al [132] examined the fungi M. anisopliae and B. bassiana, mixed into non-toxic protein bait.…”

Current Knowledge About Microorganisms Used in Biological Control of Pests and Their Relation to Bees: A Review

“…However, it could be a useful helper together with other actions. Poidatz et al (2019) discovered Beauveria bassiana as naturally parasitizing fungi in hornet Vespa velutina Buysson c , a predator of bees that was accidentally introduced in Europe from China in 2004 and suggested to consider its use in biocontrol. In Russia, wax moth larvae became more susceptible to fungal infections after envenomation by the ectoparasitoid Habrobracon hebetor Say c − a wasp (Polenogova et al, 2019).…”