Selection of native fungi strains pathogenic to Vespula germanica (Hymenoptera: Vespidae)

Abstract

The yellowjacket wasp, Vespula germanica F., is considered a serious pest of productive and recreational activities worldwide. A pathogenicity study was carried out with 29 strains of Metarhizium anisopliae and 30 of Beauveria bassiana against worker and male wasps. Wasps of the same age were fed with liquid sugar baits containing 1 × 108 conidia mL-1 suspensions of each strain. The highest mortality and sporulation were obtained with the strains QuB941 and Qu-B933 of Beauveria bassiana, reaching 79 and 95% mortality for workers and 66 and 73% for males, respectively. The strains were tested on workers of V. germanica with increasing amounts of bait from 0 to 1 x 108 conidia mL-1. The results also showed that 1 x 10 8 conidia mL-1 increased up to 90 and 97% the mortality of workers with Qu-B941 and Qu-B933 strains, respectively.