The University of Pretoria Institute for Sustainable Malaria Control (UP ISMC) is assisting in the design and testing of an innovative solar-powered trap to monitor mosquito populations, especially in areas where malaria and arboviruses require vector control. This joint venture brings together the engineering skills of two private sector entrepreneurs, Quentin van den Bergh and Kevin Godfrey, with the UP ISMC's Prof Leo Braack and his knowledge of mosquito ecology and behaviour. The trap is compact, comprises a suction fan that draws the mosquitoes into a trap-box, has a cluster of light-emitting diodes (LEDs) that emit specific visible and invisible wavelengths of light, which combines with carbon dioxide as attractant, and power is provided by a small solar panel that doubles as a 'roof' to protect the electronic circuit board below. An added advantage is that the unit also has a power socket to power or charge a USB device such as a mobile phone, notepad or study lamp. This is some incentive for villagers assisting in large-scale mosquito surveys or assisting researchers spending time in remote areas. The battery charge is sufficient to easily last overnight, which is the usual trapping time, and the battery will last a minimum of three years. Light traps, historically, have depended either on dry-cell disposable batteries that last a few nights before having to be discarded, or rechargeable 6-volt batteries that are bulky and need to be connected to an electrical outlet for several hours of recharging. This new version is a more convenient and practical design and will retail at a comparable price to the older versions.
Such mosquito traps are used for multiple purposes. Traps are an almost invariable standard approach for entomologists to determine which mosquito species are present in an area and if disease-carrying species are present. Regular standardised trapping in a particular region will reveal seasonal population trends and also some index of population numbers of particular species of Anopheles or other potential disease-carrying mosquito species in an area. If mosquito control measures are introduced into that area, use of the traps can show the impact of such control measures on mosquito numbers. Traps can be used to catch as many vector species as possible to see what percentage of those mosquitoes are actually carrying the disease organisms, and therefore what the risk of disease transmission is in that region. Work is also being done on finding attractant substances to combine with the trap so that very large numbers of mosquitoes can be caught, which directly contributes to a reduction in disease transmission risk, provided of course that enough traps are put out to saturate the region. Most of all, however, mosquito traps are a basic and essential tool of trade for medical entomologists to monitor mosquito populations, in particular species composition, relative abundance, and pathogen presence in these mosquitoes.
For more information on the Silver Bullet Mosquito trap, contact Prof Leo Braack ([email protected]), Kevin Godfrey ([email protected]) or Quentin van den Bergh ([email protected]).