Insect innate immunity involves a number of the intracellular signaling pathways, which control expression of the immune related molecules. The Toll family of receptors are involved in the intracellular signal transduction and subsequent activation of the anti-microbial peptides. Here we report isolation and characterization of a novel gene Am18w from honeybee Apis mellifera which encodes Toll related receptor 18 Wheeler and shares striking 51.4 % to Bombyx mori 18 Wheeler, 46.6 % identity to a Drosophila Toll-7 receptor and 42.5 % to Drosophila 18 Wheeler. The protein sequence analysis revealed a conserved (TIR) intracellular signaling domain characteristic of signal transducing receptors found in Toll and mammalian interleukin 1 (IL-1) receptors. The expression profile of honeybee receptor gene Am18w was examined in all developmental stages, before and after immune challenge. We have also examined effects of the gene silencing (RNAi) on the expression level of the effector molecules. Here we demonstrate that introduction of dsRNA probe into honeybee larvae successfully disrupt endogenous mRNA of the target gene. The effect of Am18w gene silencing on the expression level of the honeybee anti-microbial peptides is discussed