Physiological and molecular characterization of Metarhizium isolates and their acaricidal activity against Tetranychus urticae Koch (Trombidiformes: Tetranychidae)

• Published in: Egyptian journal of biological pest control 2022-03, Vol.32 (1), p.1-7, Article 30
• Main Authors: Cua Basulto, Marcos, Ruiz Sánchez, Esaú, Ballina Gómez, Horacio, Reyes Ramírez, Arturo, Hernández Núñez, Emanuel, Valencia Yah, Teresita, Martín Mex, Rodolfo, Chan Cupul, Wilberth
• Format: Article
• Language: English
• Subjects: Acaricides; Bioassays; Biomedical and Life Sciences; Conidia; Entomopathogenic fungi; Entomopathogenic fungus; Germination; Growth rate; Life Sciences; Metarhizium; Microbial control; Mites; Mortality; Physiology; Tetranychidae; Tetranychus urticae; Trombidiformes; Zoology
• ISSN: 2536-9342; 1110-1768; 2536-9342
• DOI: 10.1186/s41938-022-00530-w

Background The two-spotted spider mite, Tetranychus urticae Koch (Trombidiformes: Tetranychidae), is one of the most damaging mites in agriculture. Due to the concern for the intensive use of synthetic acaricides, entomopathogenic fungi represents a feasible alternative to T. urticae management. In the present study, 7 isolates of Metarhizium were characterized physiological and molecularly (based on the ITS1-5.8s-ITS2 rDNA) and evaluated for their acaricidal activity [mortality, mean and 90 lethal concentration (LC 50 : LC 90 ) and mean and 90 lethal time (LT 50 : LT 90 )] against T. urticae under laboratory conditions. Results Sequencing of the ITS1-5.8s-ITS2 rDNA region indicated that the 7 isolates belong to M. anisopliae . The isolates Ma114 (3.7 ± 0.006 mm day −1 ), Ma109 (3.5 ± 0.009 mm day −1 ) and Ma106 (3.5 ± 0.006 mm day −1 ) had the highest radial growth rate and Ma114 (92.2 ± 0.86%) and Ma108 (94.4 ± 1.07%) had the highest germination percentage. All isolates were pathogenic to T. urticae , causing mortality that ranged from 45.3 to 85.3%. The LC 50 and LC 90 were 1.2 and 2.8, 1.1 and 2.5, and 1.2 and 2.8 × 10 8 conidia mL −1 for isolates Ma110, Ma109 and Ma106, respectively, while the LT 50 and LT 90 were 7.7 and 16.5, and 7.2 and 16.1 days for isolates M110 and Ma109, respectively. Conclusion The isolates Ma110 and Ma109 of M. anisopliae were moderately pathogenic and virulent against T. urticae .