Leishmaniasis in the Jordan Valley. III. Nocturnal activity of Phlebotomus papatasi (Diptera: Psychodidae) in relation to nutrition and ovarian development.

Abstract

Nocturnal activity of Phlebotomus papatasi in the Jordan Valley was monitored by trapping flies exiting and entering burrows of the sand rat Psammomys obesus. Exit-entrance traps were placed from dusk to midnight and from midnight to dawn on burrow openings. A total of 1,576 flies was caught. Most flies caught in the 1st half of the night (79.1%) were exiting, while most caught in the 2nd half of the night (77.3%) were entering burrows. Examination of the stage of ovarian development and blood-feeding status of the females indicated that these factors affected female activity patterns: 33.7% of females caught between dusk and midnight were at advanced stages of ovarian development, while only 6.4% of those caught between midnight and dawn were in a similar condition. In addition, 59.2% of the females and 39% of the males exiting burrows between dusk and midnight had fructose in the gut, while 79.2% of the females and 81.4% of the males entering burrows between midnight and dawn were positive for fructose. The implications of these results for the understanding of sand fly behavior in the field are discussed.