Last of the mosquitoes, and thanks to the community

By Kathryn Dryden

At the end of May, the last non-biting sterile male Aedes aegypti mosquitoes were set free in Debug Innisfail’s study sites, to find their wild female match.

The Debug Innisfail project in the Northern Cassowary Coast has now wrapped up with the release of over three million non-biting sterile male Aedes aegypti in order to test technology to reduce the risk of disease spread by suppressing the population of the invasive mosquito.

A mad mozzie season

The Aedes aegypti is one of nearly 30 mosquito species found locally, and they are responsible for transmitting diseases such as dengue and Zika.

“This year’s summer has been a shocker with biting mosquitoes, particularly due to all the rain as they love to breed in water. I’ve noticed smaller black mosquitoes around as well, which hover around but don’t bite. I know that they are the males that the Debug Innisfail van releases outside of my house,” said Goondi Bend resident Alf Joyce.

Our boys at work

The Debug Innisfail van worked its way around the neighbourhoods of South Johnstone, Mourilyan and Goondi Bend, releasing male mozzies three times a week since the end of 2017.

As male mosquitoes only live for 3-4 days, regular releases were necessary to keep the pressure on the wild female population. They have had to outcompete the wild males and essentially get to the females first. Over time, the project team could see the population of the invasive mosquito decline in the treatment sites in comparison to the control sites of Belvedere, South Innisfail and Wangan.

Thanks to the community

“Whilst residents and businesses in the study sites may have noticed higher than normal numbers of non-biting male Aedes aegypti mozzies in their homes and yards, the van driving around three times a week, and visits from our field staff, they have adapted to and even embraced our research,” said the project’s lead scientist Dr Nigel Beebe.

“We warmly thank these individuals, families and business people for their valuable support,” he said.

Engagement important

Establishing and maintaining community support for the project was essential to its success. The project team worked hard to keep the community informed about the goals and progress of the study, and what was happening on the ground. Particular emphasis was placed on those living in the study sites.

“It’s been great to see the scientists travel to Innisfail on a regular basis to talk with us,” said Mr Joyce.

Mr Joyce was on the community advisory group for the project. “I have found Dr Beebe’s monthly presentations to the Project Advisory Group very interesting, and I think it’s terrific that the local team offered science lessons to schools and presentations to community groups to help get the word out,” he said.

“As a resident in Goondi Bend, I got flyers in the mailbox every now and then, giving me updates on what’s going on.”

Celebrating the results

A celebration to thank the community for their support was held at Warrina Lakes in Innisfail on Wednesday 15 July 2018, where Dr Beebe, CSIRO’s Debug Innisfail project lead, and some of the Debug Innisfail team shared the excitement of what was achieved in the community as a result of the project.

Over forty interested community members attended from around the Northern Cassowary Coast.

Mr Joyce opened the formalities with a Welcome to Country on behalf of the Mamu Rainforest Aboriginal People, and expressed his gratitude of the level of engagement undertaken by the project team.

Crs Jeff Baines and Ben Heath spoke on behalf of the Cassowary Coast Regional Council. Both Councillors have been involved in the project from a very early stage, assisting in informing the Mayor, Council and sharing information across relevant government bodies. Cr Baines said Council had been excited to be involved in a cutting edge project.

Dr Nigel Beebe then shared the results with attendees, emphasising the community’s important role in supporting the study. He said that the team achieved over 80% suppression of the local Aedes aegypti populations in the study sites.

Take a look at this media release for more on the results.

What’s next?

This phase of Debug Innisfail has now wrapped up, and the team hope to continue monitoring the population of Aedes aegypti mosquitoes in the study sites over the coming mosquito season. Join the project’s Facebook group (CSIRO Innisfail Sterile Male Mozzie Research Project) to stay in the loop for any future work, or visit the website.