Council ready to battle midges

Janet Profit hopes she can play outside with her grandchildren on Christmas Day without being chased inside by a plague of midges.

‘‘For 10 years I’ve not been able to do this.’’

Profit and other Aranui residents living near the Christchurch City Council’s wastewater treatment plant have kept their windows and doors closed in summer to prevent being invaded by tens of thousands of tiny midges.

The council has stepped up measures to reduce midge numbers this year following pressure from residents.

Profit said she hoped the additional measures would work so she and her neighbours could open their windows and doors and enjoy a barbecue outside this summer.

Midge numbers so far were lower than last year’s, but the warm summer weather had yet to fully hit, she said.

‘‘We don’t want them reduced, we want them gone.’’

Council water and wastewater operations manager Adam Twose said the oxidation ponds were now being dosed every two weeks with slow-release methoprene pellets that would prevent the larvae from developing into adults.

‘‘Methoprene is commonly found in flea treatments for dogs and cats and in home insect sprays. It is not very toxic, except to midges and fleas, and it won’t significantly impact on the bird or water life in the ponds .

Typically it does keep the midge numbers lower than if we weren’t dosing.’’

The council would also apply a contact insecticide on the vegetation around the ponds.

The insecticide would act in the same way as domestic long-lasting surface fly sprays.

‘‘Again it has a low toxicity and shouldn’t cause any unintended harm.’’

Both actions started in October and would continue until midMarch.

They were expected to cost the council $288,500.