First report of Beauveria bassiana in the in vivo control of Eriosoma lanigerum in Brazilian apple trees

Abstract

This study was conducted in a commercial apple orchard (Malus domestica) with high woolly apple aphid (Eriosoma lanigerum) incidence, which is highly harmful to apple culture and infects the trunk, branch, roots, shoot, and fruit.Although the fungus Beauveria bassiana is widely reported as a control agent, there is no evidence of its control action against this pest. This case study was conducted under natural infestation conditions to evaluate the effective action of B. bassiana in E. lanigerum nymph mortality and aimed to evaluate the control potential of E. lanigerum treated with different formulation doses based on B. bassiana strain ICBBb252. The experimental unit consisted of ten plants in four randomized blocks, where one colony per plant was previously marked in an orchard (2500 plants/ha). The treatments consisted of applying the formulate in 100, 200, and 300 mL/ha dosages at a 10 9 spore/mL concentration and one control group; 10, 20, 30, and 40 days after application, the treatments were evaluated by counting the number of colonies alive.The control of woolly apple aphids by B. bassiana strain ICBBb252 was more effective at 200 and 300 mL/ha dosages and has no phytotoxic effects on plants.