Carnauba wax as virulence enhancer of entomopathogenic fungi against the blowfly Lucilia sericata La cera di carnauba come carrier dielettrico per aumentare l’efficacia di funghi entomopatogeni contro la mosca carnaria Lucilia sericata

The blowfly, Lucilia sericata (Diptera: Calliphoridae), is a problematic synanthropic insect pest cause of secondary myasis, a severe medical and veterinary parasitosis, and vector of microbial pathogens. Fungal biopesticides are considered valid tools, alternative to synthetic ones. However, to date, little is known about their bioactivity against blowflies. In this work we assessed the insecticidal activity of the three entomopathogenic fungi Beauveria bassiana, Akanthomyces muscarius, and Beauveria pseudobassiana against L. sericata. In addition, we tested powdered carnauba wax (Copernicia prunifera) as an electrically charged carrier to enhance the virulence of the fungal spores. Pathogenicity tests on adult flies by adult immersion in conidial suspension (108 conidia mL-1) indicated B. bassiana as the most virulent followed by A. muscarius, and B. pseudobassiana. In contact test with dry conidia the percentage of mortality estimated by ANCOVA model (controlled factors, time and concentration: time = 7.23 days, concentration = 3.7 X 108 conidia/g) varied from 56.4 to 13.6% for B. bassiana, and A. muscarius, respectively. Overall, the mean mortality without carnauba wax was 31.9%, while with the carnauba as a dielectric carrier wax 40.3%. Overall, our results indicated B. bassiana as the most virulent among the tested fungi and that the use of carnauba wax as carrier is able to significantly enhance the bioactivity of the entomopathogenic fungi.