Resumo

TORIELLO, Conchita et al. Virulence and thermotolerance of monospore cultures of Metarhizium anisopliae var. anisopliae isolated from spittlebugs (Hemiptera: Cercopidae). Rev. Mex. Mic [online]. 2008, vol.28, n.spe, pp.57-66. ISSN 0187-3180.

The virulence and thermotolerance of 18 monospore cultures of Metarhizium anisopliae var. anisopliae derived from isolates of the spittlebug (Aeneolamia sp.) in sugarcane were tested. Virulence was determined by the median lethal time (LT₅₀) in Tenebrio molitor (Coleoptera: Tenebrionidae) pupae and thermotolerance by fungal growth at 25, 30, 35 and 40 °C. Thermotolerance of monospore isolates was studied by the diameter of the fungal colonies at day 14. Virulence results revealed EH-481/1, EH-469/6, EH-476/3, EH-474/6, EH-475/2 y EH-473/4, with a LT₅₀ of 5.19, 5.76, 5.97, 6.04, 6.15 and 6.53 days, respectively. The highest growth of isolates and of reference strain FI-1029, correspond ing to M. anisopliae var. anisopliae, same as the isolates from Mexico, occurred at 25 and 30 °C. Growth at 35 °C was very low, and no growth occurred at 40 °C. Results show the relevance of virulence and thermotolerance studies for strain selection to be used as biological control microbial agents.

Palavras-chave : biological control; entomopathogenic fungi; agricultural pests.