Knols Bart G J, Njiru Basilio N, Mathenge Evan M, Mukabana Wolfgang R, Beier John C, Killeen Gerry F
International Centre of Insect Physiology and Ecology, Mbita Point Research and Training Centre, PO Box 30, Mbita Point, Kenya.
Malar J. 2002 Dec 18;1:19. doi: 10.1186/1475-2875-1-19.
The development and implementation of innovative vector control strategies for malaria control in Africa requires in-depth ecological studies in contained semi-field environments. This particularly applies to the development and release of genetically-engineered vectors that are refractory to Plasmodium infection. Here we describe a modified greenhouse, designed to simulate a natural Anopheles gambiae Giles ecosystem, and the first successful trials to complete the life-cycle of this mosquito vector therein.
We constructed a local house, planted crops and created breeding sites to simulate the natural ecosystem of this vector in a screen-walled greenhouse, exposed to ambient climate conditions, in western Kenya. Using three different starting points for release (blood-fed females, virgin females and males, or eggs), we allowed subsequent stages of the life-cycle to proceed under close observation until one cycle was completed.
Completion of the life-cycle was observed in all three trials, indicating that the major life-history behaviours (mating, sugar feeding, oviposition and host seeking) occurred successfully.
The system described can be used to study the behavioural ecology of laboratory-reared and wild mosquitoes, and lends itself to contained studies on the stability of transgenes, fitness effects and phenotypic characteristics of genetically-engineered disease vectors. The extension of this approach, to enable continuous maintenance of successive and overlapping insect generations, should be prioritized. Semi-field systems represent a promising means to significantly enhance our understanding of the behavioural and evolutionary ecology of African malaria vectors and our ability to develop and evaluate innovative control strategies. With regard to genetically-modified mosquitoes, development of such systems is an essential prerequisite to full field releases.
在非洲,开发和实施用于疟疾控制的创新病媒控制策略需要在封闭的半野外环境中进行深入的生态学研究。这尤其适用于开发和释放对疟原虫感染具有抗性的基因工程病媒。在此,我们描述了一种经过改良的温室,旨在模拟冈比亚按蚊自然生态系统,并首次成功完成了该蚊媒在其中的生命周期试验。
我们在肯尼亚西部一个暴露于环境气候条件下的带纱窗的温室中建造了一个当地房屋,种植了作物并创建了繁殖场所,以模拟该病媒的自然生态系统。我们从三个不同的起始点进行释放(饱血雌蚊、未交配雌蚊和雄蚊或蚊卵),然后在密切观察下让生命周期的后续阶段进行,直到完成一个周期。
在所有三项试验中均观察到了生命周期的完成,这表明主要的生命史行为(交配、吸食糖类、产卵和寻找宿主)均成功发生。
所描述的系统可用于研究实验室饲养和野生蚊子的行为生态学,并适用于对转基因的稳定性、适合度效应和基因工程病媒的表型特征进行封闭研究。应优先考虑扩展这种方法,以实现连续维持连续和重叠的昆虫世代。半野外系统是一种很有前景的手段,可显著增进我们对非洲疟疾病媒行为和进化生态学的理解,以及我们开发和评估创新控制策略的能力。对于转基因蚊子而言,开发此类系统是进行全面野外释放的必要前提。