Galleria mellonella L. larvae were reared on a standard artificial diet amended with various concentrations (0.5%, 1.0%, 1.5%, and 2.0%) of the aminocoumarin DNA gyrase inhibitor antibiotic drug novobiocin. The effects of the inhibitor on survival and development of the larvae were measured. Survival rates for 7th instars, pupae, and emerging adults were 90.0%, 86.2%, and 76.2%, respectively, in the control diet. These rates were decreased to 15.0%, 7.5%, and 6.2% for larvae fed the diet with the highest novobiocin concentration (2.0%). High concentrations of the antibiotic caused prolongation in the larval, pupal, and adult developmental periods. Our results indicate that this gyrase inhibitor can be used as dietary additive in artificial rearing of G. mellonella when its concentrations are ascertained.