Pathogenicity bioassays of Hirsutella thompsonii fisher and H. nodulosa petch strains facing up to Tetranychus urticae Koch.
The objective of this work was to determine, trough bioassays, the most virulent strains of Hirsutella to be used as a control alternative in a pest intregrated wield program are those which are most pathogenic to CL50 just as H. nodulosa (HnC83) with 5 x 10(5) conidia/ml, and H. thompsonii (HtMOR and HtM5) with 1 x 10(6) and 1.1 x 10(6) conidia/ml respectively. The strain we recommend to attack Tetranychus urticae is H. thompsonii HtMOR. Although it did not seem to be the most aggressive to CL50, it was the strain that required the lowest concentration (0.0014%/1.5 x 10(10)) to kill 95% of the population evaluated. At the same time, the strain that we considered as having a lower virulence was HtM2 (4 x 10(6) c/ml) and the lowest virulence was detected both in HtC59 and HtC77 (1 x 10(10) c/ml).
Unidad de Estudios de Posgrado e Investigación de Acapulco, Universidad Autónoma de Guerrero, Acapulco, Gro., México.
J L
JL
Rosas-Acevedo
J
J
Valdez-Carrasco
R
R
Alatorre-Rosas
D000818:Animals; D001681:Biological Assay; D005638:Fruit / Q000382:microbiology; D005658:Fungi / Q000472:pathogenicity*; D008925:Mites / Q000382:microbiology*