Entomopathogenic fungi naturally infecting the eucalypt bronze bug,Thaumastocoris peregrinus(Heteroptera: Thaumastocoridae), in Uruguay

• DOI: 10.1111/jen.12624
• Publication Date: 2019-03-26T11:41:08Z
• Authors: Belén Corallo; Sofia Simeto; Gonzalo Martínez; Demian Gómez; Eduardo Abreo; Nora Altier; Sandra Lupo
• Keywords: 0106 biological sciences; 0301 basic medicine; 03 medical and health sciences; 15. Life on land; 01 natural sciences

AbstractThaumastocoris peregrinusCarpintero & Dellapé (Heteroptera: Thaumastocoridae) is a sap‐sucking insect that feeds on leaves ofEucalyptus.In Uruguay, it was detected in 2008 causing significant economic losses inEucalyptusplantations. At present, there is no efficient control for this pest; thus, the use of biological control agents seems to be an environmentally friendly alternative to reduce the damage caused by this insect. The aims of this study were to isolate and identify the species of entomopathogenic fungi that naturally infectT. peregrinusin Uruguay and to characterize and select the most virulent isolates towards this pest.Individuals ofT. peregrinuswere collected in eightEucalyptusplantations infested by the pest. The entomopathogenic fungi were isolated and identified by observation of their micromorphological characteristics, and their identity was confirmed by molecular methods. The pathogenicity and virulence againstT. peregrinusof the isolated entomopathogenic fungi were evaluated. Isolates causing the highest insect mortality were selected to evaluate the effect of temperature and water activity on conidial viability. Entomopathogenic fungi were found in very low number with the prevalence of less than 3%. Isolates corresponded toBeauveria,Fusarium,Isaria,Lecanicillium,Paecilomyces,Pochonia,PurpureocilliumandSimplicilliumgenera. Two species,B. pseudobassianaandL. muscarium,were first recorded in Uruguay. Among all the tested species, an isolate ofB. bassiana(FI 2403) showed the highest virulence followed by an isolate ofB. pseudobassiana. The isolate ofB. bassianapresented the highest percentage of spore germination at the three temperatures and the highest viability at low water activities. Isolate FI 2403 was selected as a promissory candidate for the development of a commercial formulation againstT. peregrinus.