Table 9 Comparison of the number of genes encoding for odorant receptors (ORs), odorant binding proteins (OBPs), chemosensory protein (CSPs), gustatory receptors (GRs), ionotropic receptors (IRs), and sensory neuron membrane proteins (SNMPs) identified in the genomes of the honeybees (Apis mellifera) and two stingless bees (Melipona quadrifasciata and Frieseomelitta varia)