Aims: 

Inorganic insecticides are commonly used in pest management because of their low toxicity to nontargets beneficial insects, mammals and environment. In this paper we test the effects of sodium tetraborate on life parameters of Galleria mellonella (L.) for assessing its sublethal toxicity on insects.

Methods: 

The effects of sodium tetraborate on survival, development, adult longevity, and fecundity of greater wax moth Galleria mellonella L. were investigated by rearing the larvae on artificial diets containing 0.005, 0.1, 0.2 or 0.3 g per 100 g of diets.

Results: 

The highest concentration of sodium tetraborate (0.3 g) significantly decreased the survival rate of 7^th instars to 17.5 ± 2.9% and prolonged the time required to reach 7^th instar by 5 days. The diet containing this concentration produced 12.5% of both pupae and adult yields and also prolonged development by 5 days. When compared to adult longevity (9.0 ± 0.7 days) from control diets, adults reared with 0.2 g of sodium tetraborate survived by about 4.2 days longer (13.2 ± 1.9 days). The highest concentration of sodium tetraborate resulted in decreased adult longevity in comparison to control. Diet containing 0.005 and 0.2 g sodium tetraborate concentrations caused a significant decrease in egg production and hatchability of G. mellonella females. Oviposition of survivors in highest sodium tetraborate treatment (0.3%) was completely inhibited.

Conclusion: 

From a practical standpoint, sodium tetraborate incorporated into a bait appears to be an ideal replacement for insecticides with high toxicity to environment and nontargets. We infer that survival, development, longevity and fecundity are effective biological fitness parameters for assessing toxicity of this boron compound.