Isolation of Beauveria Strains and Their Potential as Control Agents for Lema bilineata Germar (Coleoptera: Chrysomelidae)

SIMPLE SUMMARY: The use of fungi as biocontrol agents against insect pests can be an environmentally friendly alternative to the use of chemical pesticides. In this study, 15 fungal strains were isolated and identified as Beauveria bassiana, which is a fungus that can harm insects. Consequently, we tested these strains, under laboratory conditions, against adults of Lema bilineata Germar (Coleoptera: Chrysomelidae), which is an emerging pest in Brazil. These insects showed a great sensitivity to three of the fungal isolates tested. Then, these three fungal strains were applied to the eggs of this insect and showed a rather high ovicidal capacity. Our findings showed that these fungal isolates, which have pathogenic potential as biocontrol agents against L. bilineata, are a promising alternative to chemical insecticides. However, these results must be expanded with experiments in open fields. ABSTRACT: Lema bilineata Germar (Coleoptera: Chrysomelidae) was recently reported to damage Physalis peruviana crops in Brazil. Given the potential for inflicting damage on other Solanaceae species and the lack of alternatives for controlling this pest, we assessed the pathogenicity of 15 Beauveria isolates against L. bilineata adults in vitro. In addition, three of these isolates were tested for their ovicidal effect against L. bilineata eggs. Fungal strains were isolated from mummified corpses of L. bilineata collected in a non-commercial field in Paraná, Brazil. The isolates were identified as Beauveria bassiana using molecular markers. Lema bilineata adults were susceptible to conidial suspensions of all these isolates at a concentration of 10(8) conidia mL(−1). Deaths caused by fungal extrusion were confirmed. Three strains were found to be more virulent against L. bilineata adults and showed ovicidal effects. This is the first study on entomopathogenic fungi isolated from dead insects collected from P. peruviana crops and tested against L. bilineata carried out in Brazil. The results obtained in the laboratory indicate the high potential of the use of three B. bassiana strains against L. bilineata as a biocontrol agent.