Impact of Neem Oil on Developmental Stages of Honey Bee Apis mellifera L

Toxicity of neem oil on developmental stages of Apis mellifera L. was evaluated by applying three concentrations within the marked comb cells with micropipette as single (applied only once) and multiple exposures (at one day interval up to capping of cells) on different age groups of larvae (1-2, 3-4 and 5-6 days). Results revealed that maximum survival was observed in controls (both negative and positive) and at par with 0.05% (T1) and 0.1 % (T2) concentrations. Minimum survival of larval stage was found in 1% (T3). Same trend was also observed in emerged pupae (CD=17.9) and in mortality of adult bees (CD=15.3). Significant difference in the survival of larval (p<0.05), emerged pupae (p<0.05) and mortality of adult (p<0.05) honey bees was found within stages originating from treated larvae. Both in single or multiple doses, it was found that larvae treated at 1-2 days age group was significantly affected as compared to other stages.