Ohta Shunji, Kaga Takumi
Department of Human Behavior and Environment Sciences, Faculty of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan,
Int J Biometeorol. 2014 Apr;58(3):349-59. doi: 10.1007/s00484-012-0630-y. Epub 2013 Jan 22.
Previous research models have used climate data to explain habitat conditions of Anopheles mosquitoes transmitting malaria parasites. Although they can estimate mosquito populations with sufficient accuracy in many areas, observational data show that there is a tendency to underestimate the active growth and reproduction period of mosquitoes in semi-arid agricultural regions. In this study, a new, modified model that includes irrigation as a factor was developed to predict the active growing period of mosquitoes more precisely than the base model for ecophysiological and climatological distribution of mosquito generations (ECD-mg). Five sites with complete sets of observational data were selected in semi-arid regions of India for the comparison. The active growing period of mosquitoes determined from the modified ECD-mg model that incorporated the irrigation factor was in agreement with the observational data, whereas the active growing period was underestimated by the previous ECD-mg model that did not incorporate irrigation. This suggests that anthropogenic changes in the water supply due to extensive irrigation can encourage the growth of Anopheles mosquitoes through the alteration of the natural water balance in their habitat. In addition, it was found that the irrigation systems not only enable the active growth of mosquitoes in dry seasons but also play an important role in stabilizing the growth in rainy seasons. Consequently, the irrigation systems could lengthen the annual growing period of Anopheles mosquitoes and increase the maximum generation number of mosquitoes in semi-arid subtropical regions.
以往的研究模型利用气候数据来解释传播疟原虫的按蚊的栖息地条件。尽管它们在许多地区能够足够准确地估计蚊虫数量，但观测数据表明，在半干旱农业地区存在低估蚊虫活跃生长和繁殖期的趋势。在本研究中，开发了一种新的、改进的模型，该模型将灌溉作为一个因素，以便比用于蚊虫世代生态生理学和气候学分布的基础模型（ECD-mg）更精确地预测蚊虫的活跃生长期。在印度半干旱地区选择了五个拥有完整观测数据集的地点进行比较。纳入灌溉因素的改进后的ECD-mg模型确定的蚊虫活跃生长期与观测数据一致，而未纳入灌溉的先前ECD-mg模型则低估了活跃生长期。这表明，由于广泛灌溉导致的人为供水变化可通过改变其栖息地的自然水平衡来促进按蚊的生长。此外，研究发现灌溉系统不仅能使蚊虫在旱季活跃生长，而且在稳定雨季生长方面也发挥着重要作用。因此，灌溉系统可能会延长半干旱亚热带地区按蚊的年生长期，并增加蚊虫的最大世代数。
