COMPARATIVE-STUDY OF MOUTHPARTS OF 4 SPECIES OF CULICOIDES FROM TIBET

Mouthparts of four species of Culicoides from Tibet were studied by li ght and scanning electron microscopy (SEM). Photomicrographs were made of the mandible, labrum, hypopharynx, lacinia, and the sensory pit of the third palpal segment for each of the four species. Values for eig hteen characters of five structures are presented graphically. Mean va lues for ten of the eighteen characters evaluated were significantly g reater for C.circumscriptus and C.mamaensis than for C.maculatus and C .tibetensis. Photomicrographs revealed specific differences in camber and pitch of the fifth mandibular tooth, in size and location of the s ubapical labral sensillae, in size of the teeth of the hypopharynx, an d in size and depth of the palpal sensory pit and number of sensillae per pit.