Wolbachia is found in up to 60% of all insect species including the Cairns birdwing butterfly.

Wolbachia (green) in the ovaries of Aedes aegypti mosquitoes

High magnification image of Aedes aegypti cells with Wolbachia (green)

Wolbachia is found in moths, butterflies, ladybirds and the blue damselfly (pictured).


Wolbachia is a natural bacterium present in up to 60% of insect species, including some mosquitoes. However, Wolbachia it is not usually found in the Aedes aegypti mosquito, the primary species responsible for transmitting human viruses such as dengue, chikungunya, and Zika.

For many years scientists have been studying Wolbachia, looking for ways to use it to potentially control the mosquitoes that spread human diseases. Our research has shown that when introduced into the Aedes aegypti mosquito, Wolbachia can stop these viruses from growing inside the mosquito and being transmitted to people. This important discovery has the potential to transform the fight against life-threatening viral diseases. 

Wolbachia is safe for humans, animals and the environment. It is a naturally occurring bacterium already found in the environment in many insect species. Two independent risk assessments have been conducted, both of which gave an overall risk rating of ‘negligible’ (the lowest possible rating) for the release of mosquitoes with Wolbachia.

Alternative uses of Wolbachia

Other researchers are experimenting with Wolbachia as a means of suppressing Aedes mosquito populations. This approach involves the release of only male mosquitoes with Wolbachia. When these mosquitoes mate with wild female mosquitoes without Wolbachia, they are unable to reproduce.
The technique requires the release of a large number of male mosquitoes to reduce the overall mosquito population. As with insecticides, this technique would need to be reapplied over time as the population of mosquitoes gradually returns. 
In contrast, the Eliminate Dengue Program's approach does not aim to reduce the overall number of mosquitoes. Our aim is to spread Wolbachia into wild mosquito populations to reduce the ability of these mosquitoes to transmit disease.
We release a smaller number of male and female mosquitoes with Wolbachia over a number of weeks. These mosquitoes then mate with the wild mosquito population, passing the bacteria from generation to generation. Over time, the percentage of mosquitoes carrying Wolbachia grows until it remains high without the need for further releases. Mosquitoes with Wolbachia are less able to transmit viruses to people, so the risk of outbreaks in those areas is reduced.
EDP's research has shown that Wolbachia can sustain itself in mosquito populations without continual reapplication, making it a cost-effective, sustainable and long-term solution. We are currently adapting our approach for use in large, urban environments and targeting a cost of US$1 per person.