A tiny insect that looms large in the spread of diseases in some climates is being culled with a new technique, thanks to Australian researchers.
A new study has discovered a sterilisation technique to suppress and eradicate populations of mosquitoes carrying dengue, yellow fever and Zika.
Scientists in northern Queensland released three million sterilised male mosquitoes at three sites to test whether it prevented wild females producing offspring of the Aedes aegypti mosquito.
Nigel Beebe, a CSIRO scientist and University of Queensland associate professor, said the technique was successful.
The trial started during summer in 2018, and researchers found it suppressed the populations by more than 80% in 2019. At one site in Mourilyan the technique even nearly wiped out the insect.
“When we surveyed the sites the following year, we were very encouraged to see the suppression still in effect,” Beebe said. “One of our most productive towns for Aedes aegypti almost [was] devoid of this mosquito, with a 97% reduction.”
A year later the population at the second trial site remained suppressed but had recovered at a third site, he said.
CSIRO chief Dr Larry Marshall said over 40% of humans suffered from mosquito-spread diseases and the trial was a chance to develop “environmentally-friendly mosquito control tools” to tackle future incursions.
“CSIRO is leveraging great Australian science to create new technologies to make this approach more cost effective and suitable for the climates of less developed countries that suffer most from mosquito-borne viruses,” Marshall said.
Now, techniques from the trial are supporting CSIRO-led mosquito suppression programs in French Polynesia and the Hunter region in New South Wales.
Scientists reared the three million male mosquitoes needed for the trial at the insectary in Cairns at James Cook University, where Professor Scott Ritchie said the project was “hugely successful”.
The CSIRO says the Aedes aegypti mosquito arrived in Australia from Africa more than a century ago and is found in Queensland but has been in New South Wales, the Northern Territory and Western Australia.
The trial also partnered with Verily Life Sciences, a research organisation owned by US-giant Alphabet.
The CSIRO created a health and security team in 2016, which has played a role during the COVID-19 pandemic and works on threats including mosquito-borne diseases.