THOUSANDS of mozzie-infested saltmarshes and swamps in Brisbane are being air-bombed amid fears of virus outbreaks.
King tides, sporadic storms and balmy weather have combined to ripen conditions for saltmarsh mosquitoes, which transmit Ross River and Barmah Forest viruses.
Brisbane City Council has launched air and ground raids on 3000 known mozzie breeding sites from Tinchi Tamba at Bald Hills to Tingalpa Creek, after recording tides as high as 2.7m this week.
“Council has been on the front foot to respond to king tides, with our mosquito management team starting an aerial treatment of 2000ha of saltmarsh breeding sites by helicopter,” Lord Mayor Graham Quirk said.
“The most effective time to manage mosquitoes is in the days after hatching, before the larvae develop into adults seven days after rainfall or high tides.”
Crews in trucks and on quad bikes also were used to treat the areas helicopters could not spray.
Already this year, dozens of people across Queensland have been struck down by vector-borne diseases.
In the first two weeks of the year, almost 100 people were diagnosed with Ross River Fever. More than 2240 cases were recorded in 2014, one of the worst years for the disease on record.
About 470 people contracted Barmah Forest virus last year. Both illnesses are spread by saltmarsh mosquitoes, or Aedes vigilax .
Ten cases of dengue fever have been confirmed in Cairns but that disease is transmitted by mosquito species not detected in Brisbane
Dr Nigel Beebe, a vector biologist from the University of Queensland and CSIRO, said aside from their tendency to infect humans, saltmarsh mosquitoes were a pain-inflicting pest.
“They’re the ones biting you during the day,” he said.
“They’re really aggressive.”
Brisbane’s council was one of the best in Australia for controlling mozzies but eradicating them completely was impossible, Dr Beebe said.
“Even if you get 90 per cent of the larvae, the 10 per cent that still hatch means there are still millions and millions of mosquitoes,” he said.
“They’re good flyers. You can find them 50-60km inland — even further — because they come in on the sea breezes.”
Brisbane City Council’s mosquito control team has completed 10 major aerial sprays of 11,500ha of tidal saltmarshes in the past six months.
“Council spends approximately $3.5 million each year on mosquito management and this amount is supplemented when necessary to respond to weather events,” Cr Quirk said.