Variation in the Susceptibility of Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) When Reared on Different Host Plants to the Fungal Pathogen, Beauveria bassiana in the Field and Laboratory!

Environ. En!om,,!. 12: 1892-1897 (1983) ABSTRACT We determined the susceptibility of the Colorado potato beetle, Leptinotarsa decem/ineata (Say) to the fungal pathogen Beauveria bassiana (Balsamo)when reared on So/anum tuberosum L., So/anum dulcamara L., So/anum carolineme L., and Lycopersicwn escu/entum Miller growing in both the field and greenhouse. With the exceptionof L. escu/entwn, the host plant speciesmost suitable for L. decem/ineata survival in the field produced L. decemlineata larvae least susceptible to B. bassiana. Larvae reared on different host plants in the greenhousealso varied in susceptibilityto measured doses of B. bassiana conidia in the laboratory.Greenhouse-grownplants, however, appearedto be less suitable for L. decemlineata growth than field-grown plants, and host plant suitability declined with host plant age. L. escu/entum declined most in suitability, and larvae reared on this host in August were more susceptible to B. ba.uiana in the laboratory than larvae reared on the same plants in June.