Morphological characteristics of the antenna and its sensilla of three stored-product beetle species

Abstract Background Antenna is one of the essential appendages in insects for behaviour and survival in the environment. In the present study, morphological characteristics of antenna and density of sensilla in the antennal flagellomere of three major stored-product insect pests namely, Callosobruchus maculatus , Sitophilus oryzae , and Tribolium castaneum , were examined using scanning electronic microscopy. Results In C. maculatus, S. oryzae and T. castaneum adults, serrate, geniculate, and capitate type of antennae was observed , respectively. Further, estimation of sensilla density in the flagellomeres of antenna showed low density in S. oryzae (6.33/10,000 µm 2 area) while higher density in C. maculatus (88.00/10,000 µm 2 area) and T. castaneum (26.67/10,000 µm 2 area) significantly ( p < 0.0001). The study findings indicate that 13.90 and 4.21 fold of sensilla density was higher in C. maculatus and T. castaneum , respectively, compared to S. oryzae . Conclusions Various roles of antenna such as foraging food, reproduction and discriminatory behaviours are discussed in this study with respect to sensilla types and density.