A COMPARISON OF CHORIONIC SCULPTURING OF 4 INDIAN PHLEBOTOMINE SANDFLIES (DIPTERA, PSYCHODIDAE) BY SCANNING ELECTRON-MICROSCOPY

The chorionic sculpturing of four indian sandfly species: Phlebotomus argentipes Annandale & Brunetti, P. papatasi (Scopoli), P. major major Annandale and Sergentomyia zeylanica (Annandale) was investigated wit h the help of scanning electron microscopy. it was found that P. argen tipes and P. papatasi show similar type of chorionic sculpturing i.e., parallel connected ridges and ridge column palisade consisting of sev eral small granules spaced in a double series, arranged longitudinally . However, morphology of each ridge is very different, particularly ne ar the two ends of the eaa and also where there is a formation of hexa gonal areas. The interridge area and basal layer of P. papatasi egg sh ow multiple granular elevation which look like multiple minute microvi lli like projections whereas in case of P. argentipes, there is reticu lar structure formation by fibrous material. in P. m. major and S. zey lanica, the egg surface pattern is found to be polygonal but in case o f S. zeylanica almost all the polygons are of equal sizes and each rid ge consists of flattened cells of different sizes arranged in a palisa de. On the other hand, in P. m. major, there is no uniformity on the s ize and shape of the polygons and they look like that the ridges are f ormed by the fusion of the flattened cells. These species specific cha racters will be useful in identifying different sandfly species on the basis of their chorionic sculpturing pattern and consequently ii will help to indicate the relatedness of sandfly species i.e., sandfly tax onomy.