Vertical distribution of phlebotomine sandflies in two habitats in marigat leishmaniases endemic focus, baringo district, Kenya

Abstract

Studies on the vertical distribution of phlebotomine sandflies were carried out at Marigat (Kenya) at determined heights above ground level in both wooded and open fields. Traps set up at different heights from 0–11 m (in wooded area) and 0–9 m (in open field), showed a clear vertical zonation of sandflies as large numbers were collected between 0–7 m in the first site and 0–4 m in the second ones. Among the nine sandfly species collected, Sergentomyia bedfordi Newstead and S. antennatus Newstead were the only species recorded at a height of 11 m above the ground and the commonest sandflies at all studied heights. Overall, more sandflies were collected from the wooded area than the open field. The relationships between the sandfly relative abundance and their heights of flight above the ground showed significant negative correlation coefficients. Des etudes sur la distribution verticale des phlebotomes ont ete menees dans deux zones differentes dans la Localite de Marigat (Kenya). Dans la region boisee, les pieges “collant” places du sol jusqu’a onze metres ont defini la zone de vol comme etant comprise entre le niveau du sol (O metre) et sept metres au-dessus du sol. Tandis que dans la region deboisee (endroit ouvert), les pieges installes de zero jusqu’a neuf metres ont determine la zone de vol comme etant situee entre zero et quatre metres au-dessus du sol. Parmi les neuf especes de phlebotomes rencontrees dans la Localite de Marigat, seules Sergentomyia bedfordi et S. antennatus ont ete collectees jusqu’a onze metres au-dessus du sol. Les deux especes etant aussi les plus communes a toutes les hauteurs examinees. Dans l’ensemble, la zone boisee renfermait plus de phlebotomes par rapport a l’endroit ouvert. Le rapport entre l’abondance relative des phlebotomes et leur distance de vol au-dessus du sol a presente un coefficient de correlation negatif hautement significatif.