ARC, Onderstepoort Veterinary Institute, Pretoria, South Africa.
Acta Trop. 2011 Mar;117(3):171-82. doi: 10.1016/j.actatropica.2010.11.003. Epub 2010 Nov 16.
The hypothetical impact of aerial spraying on tsetse fly populations is investigated. Spray cycles are scheduled at intervals two days short of the first interlarval period and halted once the last of the female flies that originated from pre-spray-deposited pupae have been sprayed twice. The effect of temperature on the aerial spraying of tsetse, through its reproductive cycle and general population dynamics, is of particular interest, given that cooler weather is preferred for the settling of insecticidal droplets. Spray efficacy is found to come at a price due to the greater number of cycles necessitated by cooler weather. The extra cost is argued to be worth while. Pupae, still in the ground at the end of spraying, are identified as the main threat to a successful operation. They are slightly more vulnerable at the low temperature extreme of tsetse habitat (16°C), when the cumulative, natural pupal mortality is high. One can otherwise base one's expectations on the closeness with which the time to the third last spray approaches one puparial duration. A disparity of anything close to the length of a spray cycle advocates caution, whereas one which comes close to vanishing should be interpreted as being auspicious. Three such key temperatures, just below which one can anticipate an improved outcome and just above which caution should be exercised, are 17.146°C, 19.278°C and 23.645°C. A refinement of the existing formulae for the puparial duration and the first interlarval period might be prudent in the South African context of a sympatric Glossina brevipalpis-Glossina austeni, tsetse population. The resulting aerial spraying strategy would then be formulated using a G. brevipalpis puparial duration and a G. austeni first interlarval period.
研究了空中喷雾对采采蝇种群的假设影响。喷雾周期安排在第一次幼虫期前两天的间隔内，如果最后一批来自预喷沉积蛹的雌蝇已经被喷了两次，就会停止。鉴于凉爽的天气有利于杀虫液滴的沉降，温度对采采蝇的空中喷雾的影响，通过其生殖周期和一般种群动态，特别令人感兴趣。由于天气较凉爽需要更多的周期，喷雾效果会付出代价。有人认为，额外的成本是值得的。在喷洒结束时仍在地下的蛹被认为是成功作业的主要威胁。当采采蝇栖息地的温度（16°C）处于低温极端时，即累积的自然蛹死亡率较高时，它们的脆弱性略有增加。否则，人们可以根据接近第三次最后一次喷雾的时间与一次蛹期持续时间的接近程度来预测结果。接近或接近喷雾周期长度的差距表明需要谨慎，而接近消失的差距则表示是有利的。在接近 17.146°C、19.278°C 和 23.645°C 这三个关键温度下，人们可以预期结果会得到改善，而在略高于这些温度时则应保持谨慎，这三个温度略低于预期会改善结果的温度，略高于需要谨慎的温度。在南非 Glossina brevipalpis-Glossina austeni 采采蝇种群共生的情况下，对蛹期和第一次幼虫期的现有公式进行细化可能是明智的。然后，使用 G. brevipalpis 蛹期和 G. austeni 第一次幼虫期来制定空中喷雾策略。
