Studies on Biological Control of the Greater Wax Moth,Galleria MellonellaI. Susceptibility of Wax Moth Larvae and Adult Honeybee Workers toBacillus Thuringiensis

Abstract

SummarySusceptibility of 3rd, 5th and 7th instars of Galleria mellonella to Bacillus thuringiensis was studied by feeding the larvae on artificially treated media. For the third instar, the LC50 values 48 and 168 hours after treatment started were 9 × 108 and 0·2 × 108 viable spores/g medium, respectively, and the LC90 value after 168 h was 30 × 108 spores. The corresponding figures for the 5th instar were 108 × 6·6, 1·9 and 150, and for the 7th instar 108 × 9, 0·8 and 90 respectively. Surviving larvae fed on treated media were small and gave rise to undersized adults, greatest effects being produced by the higher concentrations on the youngest instars. When larvae (3rd–4th instar) were fed on pieces of comb dipped in different concentrations of Thuricide-HP suspension for 1 min, LC50 was 108 × 32 and 0·12 viable spores/g suspension 48 h and 168 h after treatment began. When the combs were dipped for 3 min, LC50 was 108 × 3 and 0–013 after 48 and 168 h, respectively.LC50 and LC90 for adult worker honeybee...