Figure 8

Metamorphosis of G. mellonella larvae following infection with bacterial and fungal pathogens. (A) Injection of pathogenic L. monocytogenes or non-pathogenic E. coli into last-instar larvae induced opposing developmental effects. Infection with non-pathogenic E. coli induced the precocious formation of pupae whereas infection with pathogenic L. monocytogenes caused a significant delay in comparison to control larvae treated with 0.9% NaCl. The larvae were incubated at 37°C and reared on an artificial diet. (B) Application of conidia from different entomopathogenic M. anisopliae strains to the cuticle of last-instar larvae resulted in infection and induced opposing developmental effects. Infection with strains 43 and 97 delayed the formation of pupae whereas infection with strain 79 accelerated pupation. The larvae were incubated at 25°C and reared on an artificial diet. Results represent mean values of at least three independent measurements ± standard deviations from at least 20 larvae per treatment (*, p < 0.05; **, p < 0.005; ***, p < 0.0005).