Discrimination attempt of simulids adults females (Diptera: Simuliidae) in Nuku-Hiva, Marquesas Archipelago (French Polynesia)

Simulium sechani Craig & Fossati, 1995 was recently found for the first time in a part of Nuku-Hiva Island. This species coexists with Simulim buissoni Roubaud 1906, the dominant species, and always regarded as the main biting fly on the island. The problem is that optimisation of control operations needs a good knowledge of targets. The unknown female of S, sechani is the reason of this study. This study used samples collected before the description of S. sechani to try to correlate its geographical extent with easy to use biometrical parameters, and then give a first look at the possibilities of determination of adult females. Parameters used are: the numbers of maxillar and mandibular teeth, the dimension of the third antenna article and the number of apical hairs, the width and depth of the Ventral plate space, and the number of hairs on the radial Vein of the wing. Analysis of frequency distributions in relation with sampling sites and trapping hosts did not allow us to find convenient diagnosis characters, bur contributed to new questions about isolation of insect populations in valleys and hosts usually used.