Central Projections of Antennal Sensory Neurons in the Aphid Myzus persicae

The aphid <i>Myzus persicae</i> is an important agricultural pest relying on olfactory cues to find food and escape from predators. The considerable difficulty of anatomical manipulation and other related technical challenges may underlie the absence of studies systematically mapping the central projections of antennal sensory neurons in its central nervous system. We used mass stain, immunohistochemistry, laser scanning confocal microscope and three-dimensional reconstruction techniques to trace the central projections of sensory neurons from the antennae. The ipsilateral antennal nerve targets mainly the antennal lobe, the antennal mechanosensory and motor center, and most neuromeres of the ventral nerve cord. There are also several axons that project to other regions, like the contralateral antennal lobe, the contralateral antennal nerve, the ipsilateral calyx and some region of the protocerebrum. The numerous neuropils innervated by axons from the antenna indicate the multiple roles that this sensory organ serves in insect behavior, and the results which provide information about the basic anatomical arrangement of the olfactory nervous system in aphid <i>M. persicae</i> may provide some basic knowledge for the further investigations of the aphid.