THE EFFECT OF LOW-TEMPERATURES ON THE VIRULENCE OF METARHIZIUM-ANISOPLIAE (DAT F-001) TO THE SUBTERRANEAN SCARAB, ADORYPHORUS-COULONI

Metarhizium anisopliae DAT F-001 spores are able to germinate on Czape k-dox agar at all temperatures from 2 to 25 degrees C. The effect of t emperature on the virulence of in. anisopliae DAT F-001 for Adoryphoru s couloni was tested by exposing third-instar larvae to a concentratio n of 4.1 x 10(6) spores/g in sand-peat mixes at temperatures of 5, 10, 15, and a fluctuating 15/5 degrees C regime. DAT F-001 was pathogenic at all temperatures and the LT,, values ranged from 36.1 days at 15 d egrees C to 188.9 days at 5 degrees C. There was no difference in viru lence of the fungus for A. couloni at either a 10 degrees C constant o r a fluctuating 15/5 degrees temperature. (C) 1995 Academic Press, Inc .