The effect of endophytic colonization of wheat plants by the fungus Beauveria bassiana on the development of the nymphs of the migratory and desert locusts

Abstract

The experiments were aimed at evaluation of the effect of feeding with wheat colonized by the fungus Beauveria bassiana on the development of locusts. The seeds were treated with fungal conidia and 90 days after sowing, the plant parts were fed to II instar nymphs of laboratory colonies of migratory and desert locusts within the period of 18 days. The mortality levels between experimental and control (fed with untreated wheat) groups were not significantly different though a tendency of an increase in variants with contaminated fodder was observed. Two weeks after the beginning of the bioassay, insect mortality was 20-30% and 15% in control. As many as 50% of migratory locust and 40% of desert locust cadavers were covered by a fungal mycelium. Sequencing of two diagnostic DNA loci has confirmed attribution of the reisolate to the genotype of the initial Beauveria bassiana strain BBK-1. It can be therefore concluded that the endophyte fungus is capable of causing classical pathogenesis of mycosis in locust nymphs. Moreover, the nymphal development was retarded by feeding with the fungus-colonized plants.