SINGAPORE: Male Wolbachia-carrying mosquitoes will be released at expanded sites in Nee Soon and Tampines, under the next phase of a study to reduce the Aedes mosquito population and fight dengue.
The third phase of the National Environment Agency's (NEA) Project Wolbachia kicked off on Friday (Feb 22), with the mosquitoes released at a Nee Soon East site that is 1.6 to 2.2 times larger compared to the trial area in phase two.
Under this next phase, the mosquitoes will also be released at a larger Tampines West site.
These male mosquitoes infected with the Wolbachia bacterium do not bite or transmit diseases. If they mate with an uninfected female mosquito, the resulting eggs will not hatch.
The purpose of expanding the sites is to determine if suppression of the urban Aedes aegypti mosquito population can be sustained in larger areas, said NEA.
In the long term, this will require strategies which can reduce the number of male Wolbachia-Aedes mosquitoes being released in an area, to make the technology more sustainable.
The expansion in study sites follows the success of phase two of the study, which was conducted between April 2018 and January 2019 at smaller areas in Nee Soon East and Tampines West.
It resulted in an 80 per cent drop in the urban Aedes aegypti mosquito population at the Nee Soon East study site and a 50 per cent drop at the Tampines West study site, NEA said.
Results from the second phase also proved that a larger release site yields better results.
NEA's Environmental Health Institute (EHI) and local startup Orinno Technology have also developed a prototype of a mosquito launcher, which is designed to store male Wolbachia-Aedes mosquitoes so that they can be easily transported and later, released at high-rise residential blocks.
EHI and Orinno Technology have jointly filed five intellectual property patents for various mosquito-related solutions. This includes a larvae counter and a pupae counter.
Other devices under development include an automated feeding system, a pupae separator and an adult mosquito sex sorter.
NEA said these devices will not only help to save manpower and costs, but will also ensure the consistency and quality of the male mosquitoes produced and released.