Both ends of Queensland are buzzing with an upsurge in mosquitoes as weeks of rain, high temperatures and oppressive humidity create ideal breeding conditions for the blood suckers.
The spike has medical experts warning about the potential spread of mosquito-borne diseases, particularly Ross River virus, given the ideal conditions.
Ross River is the most common mosquito-borne virus in Queensland, with 698 cases recorded last year and 837 in 2022.
In 2020, there were more than 3,000 cases diagnosed across Queensland.
No new dengue cases
Symptoms can include a fever, swollen and painful joints, and a rash. While most people recover in a few weeks, some can experience pain and fatigue for months.
The director of Tropical Public Health Services Cairns, Richard Gair, said Far North Queensland has experienced a rise in mosquito numbers in the wake of ex-Tropical Cyclone Jasper.
In the past, a spike in the mozzie population would have triggered concerns about local transmission of the potentially deadly dengue virus.
However, Dr Gair said it had been about seven years since a locally acquired case of dengue fever had been recorded in Cairns.
The end of local dengue transmission is due to a successful program to introduce the Wolbachia bacterium into the region's Aedes aegypti mosquito population – the species that transmits dengue.
Wolbachia prevents Aedes aegypti from spreading disease by reducing the ability of dengue and other viruses to replicate in the mosquito.
"We used to get the outbreaks, when it's hot — and when we had lots of mosquitoes," Dr Gair said.
"We don't really see dengue transmission up here anymore since we had the introduction of Wolbachia.
"The disease we're most likely to see an increase in is Ross River."
Medical entomologist Jonathan Darbro, based at the Metro North Public Health Unit in Brisbane, said south-east Queensland was likewise experiencing high numbers of mosquitoes following "a lot of rainfall in December and January".
"The rainfall produces a lot of habitat for mosquito larvae to develop and then, at higher temperatures, mosquitoes are more active and they develop faster," Dr Darbro said.
"All of that combines to make a really good set of conditions to get high mosquito numbers.
"With a lot of mosquitoes, obviously the risk of virus transmission is there and so we recommend everybody take precautions to avoid being bitten."
Dr Darbro said Queensland was home to about 250 mosquito species.
Watch for pooling water
He said to avoid mosquitoes breeding around homes, people should be mindful of stagnant water in containers such as pot plant saucers, bird baths and even pet water bowls.
"A good rule of thumb is to change those kind of containers every week. If you give it two weeks, that's enough time for a mosquito egg to become an adult," Dr Darbro said.
"But if you change them every week, that won't give them enough time to produce adult mosquitoes."
Dr Darbro said part of his job was coordinating mosquito-borne virus surveillance with local governments and other public health units.
Mosquitoes are collected and tested for viruses at Queensland Health's Forensic and Scientific Services facility.
Dr Darbro agrees Ross River is the mosquito-borne virus of most concern.
In 2022, scientists began testing for potentially deadly Japanese Encephalitis virus as cases emerged across Australia.
But no new cases were recorded in Queensland last year.
Dr Darbro said the best way to avoid mosquito-borne illness was to protect against being bitten.
"We recommend people trying to avoid being out at dusk or dawn if they can help it because that's when most mosquitoes are active, to wear long sleeves, long trousers, to protect that bit of skin from being bitten, to wear a topical repellent," he said.
"When you put on repellent, make sure you put it on all your exposed surfaces because if you, say, don't do the back of your neck, or don't do your legs, the mosquitoes will find the spots that are not covered."
Dr Darbro also advised home owners to screen doors and windows.