Electron microscope scanning of diamondback moth, Plutella xylostella L.

Larvae head of diamondback moth, Plutella xylostella was investigated by electron microscope scanning. The result was as follows: the antenna on the head had 3 segments and there were some sensilla on the last and 2nd segments, which were mainly styloconic or basiconic; the dominant sensilla on the galea were also styloconic sensillum and basiconic sensillum; maxillary palpus had 2 segments which bad two placoid sensilla and 8 styloconic sensilla; there were a group of basiconic sensilla around the area where galea, maxillary palpus and labium were located; maxillary palpus had basiconic sensilla and styloconic sensilla; a pair of basiconic sensilla was located on the front of fusulus. Contact-chemosensory basis of host-plant selection behavior of caterpillars was also discussed.