Department of Molecular Genetics and Microbiology, The Institute for Medical Research Israel-Canada, The Kuvin Centre for the Study of Infectious and Tropical Diseases, The Hebrew University - Hadassah Medical School, The Hebrew University of Jerusalem 91120, Israel.
Acta Trop. 2011 Oct-Nov;120(1-2):110-4. doi: 10.1016/j.actatropica.2011.06.015. Epub 2011 Jul 2.
Phlebotomine sand flies transmit Leishmania parasites that cause leishmaniasis in humans. We report experimental results that improve our understanding of how foraging sand flies proceed over flat or sloping ground and how they negotiate vertical obstacles. Three rows of traps were suspended at different heights on a wire fence. Those just above ground level captured 87% of all flies, traps set at one meter captured 11% while only 2% of the flies were captured in traps set two meters above ground. When traps were deployed on a vertical support wall, the mean catch per trap was much higher than for traps suspended on the fence. Traps suspended just above ground level captured 57% of all flies, traps set at one meter above ground captured 27% of the flies and even traps set at two meters captured 16% of the flies. Although, most flies were still captured close to the ground, a higher percentage reached the second and third rows of traps. Sticky traps on a vertical wall produced similar results with significantly more flies alighting on the lower sections of the trap closest to the ground. On a vertical sand fly-proof net the overall dispersal of the flies was more like on a wall than in open space. Traps suspended just above ground level captured 49%, traps set at one meter above ground captured 36% and traps set at two meters captured 15% of the flies. Following spraying of the net with deltamethrin (1%), fewer sand flies were captured but the reduction was not statistically significant. Our conclusions are that being small and frail, sand flies tend to fly close to the ground probably in order to avoid being swept away by gusts of wind. When they encounter a vertical obstacle, they proceed upwards close to the obstacle with intermittent stops. Therefore, insecticide-sprayed walls or vertical nets should be effective for controlling sand flies approaching human habitation.
白蛉传播引起人类利什曼病的利什曼原虫寄生虫。我们报告了一些实验结果，这些结果增进了我们对觅食沙蝇在平地或斜坡上的行进方式以及如何越过垂直障碍物的理解。三排诱捕器悬挂在铁丝网围栏的不同高度。离地高度仅为一米的诱捕器捕获了 87%的所有苍蝇，一米高的诱捕器捕获了 11%，而两米高的诱捕器仅捕获了 2%的苍蝇。当诱捕器部署在垂直支撑墙上时，每个诱捕器的平均捕获量要远高于悬挂在围栏上的诱捕器。离地高度仅为一米的诱捕器捕获了 57%的所有苍蝇，一米高的诱捕器捕获了 27%的苍蝇，即使两米高的诱捕器也捕获了 16%的苍蝇。尽管大多数苍蝇仍靠近地面，但仍有较高比例的苍蝇到达第二和第三排诱捕器。垂直墙壁上的粘性诱捕器产生了类似的结果，更靠近地面的诱捕器下部有更多的苍蝇降落。在垂直的沙蝇防虫网中，苍蝇的整体扩散更像在墙壁上而不是在空旷空间中。离地高度仅为一米的诱捕器捕获了 49%的苍蝇，一米高的诱捕器捕获了 36%的苍蝇，两米高的诱捕器捕获了 15%的苍蝇。在防虫网喷洒了溴氰菊酯（1%）后，捕获的沙蝇数量减少，但减少量没有统计学意义。我们的结论是，由于体型小且脆弱，沙蝇往往会在靠近地面的地方飞行，可能是为了避免被阵风卷走。当它们遇到垂直障碍物时，它们会靠近障碍物向上飞行，并间歇性地停下来。因此，喷洒杀虫剂的墙壁或垂直网对于控制接近人类栖息地的沙蝇应该是有效的。
