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Our research

How our mosquito reduction method works

Female mosquitoes are responsible for transmitting viruses through blood meals (bites). Male mosquitoes don’t bite, they feed off plant nectar and spend all their energy seeking and mating with females.

Our mosquito reduction method is based on the Sterile Insect Technique (SIT) developed in the 1950s and is delivered by releasing sterile male (non-biting) mosquitoes to mate with wild females of the same species.

If the sterile Aedes aegypti male mates with a wild Aedes aegypti female the eggs she lays won’t hatch, reducing the mosquito population in the next generation. If we get our numbers right, this would mean that the Aedes aegypti mosquito population would quickly die-off.

The Wolbachia strain we are using was originally taken from the Aedes albopictus mosquito and transferred to the Aedes aegypti.

Incompatible mating – using Wolbachia to ‘sterilise’ the males

The male mosquito is ‘sterilised’ by introducing a natural bacteria called Wolbachia in the rearing process. Many different strains of Wolbachia  exist and are found in up to 60% of of all insect species; Wolbachia can not survive outside of insect cells and is not harmful to humans, animals or the environment.

When a male mosquito with Wolbachia mates with a female that doesn’t have Wolbachia, or has a different strain of Wolbachia, then the eggs she lays wont hatch.

Summer 2017/18 field studies to test the Sterile Insect Technique (SIT)

The success of our work is dependent on the sterile males we release out-competing wild Aedes aegypti males to mate with wild Aedes aegypti females.

With information we have learnt from earlier mark, release, recapture studies and technology developed by Verily our efforts are now focused on showing whether it is possible to significantly reduce the Aedes aegypti mosquito population.

– First, we will set a network of traps (including the BG trap shown here) in areas where we propose to carry out sterile male mosquito releases.

– We will release male mosquitoes over a number of weeks (up to 24 weeks) that contain a natural bacteria called Wolbachia that renders the mosquito infertile.

– We will monitor the trap network regularly before, during and after the release of sterile males to develop the ‘before’ and ‘after’ data we need to show if we are being successful in reducing mosquito numbers.

We will share the results of the studies with the community and encourage questions throughout all stages of the research.

 

We’ve been monitoring populations of mosquitoes in Innisfail since November 2015

 

We’ve been learning about the behaviour of male mosquitoes through mark, release, recapture studies in Innisfail East and Silkwood