Methodology
MalariaSphere: A greenhouse-enclosed simulation of a natural Anopheles gambiae (Diptera: Culicidae) ecosystem in western Kenya
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* Corresponding author: Bart GJ Knols bknols@planet.nl
1 International Centre of Insect Physiology and Ecology (ICIPE), Mbita Point Research & Training Centre, PO Box 30, Mbita Point, Kenya
2 Laboratory of Entomology, Wageningen University Research Centre, PO Box 8031, 6700 EH, Wageningen, The Netherlands
3 Department of Zoology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
4 Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University Health Sciences Centre, 1430 Tulane Avenue, New Orleans, LA 70112 Louisiana, USA
5 Department of Public Health and Epidemiology, Swiss Tropical Institute, Socinstrasse 57, CH-4002, Basel, Switzerland
Malaria Journal 2002, 1:19 doi:10.1186/1475-2875-1-19
Published: 18 December 2002Abstract
Background
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.
Methods
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.
Results
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.
Conclusion
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 prioritised. 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.