IGRs, such as Sumilarv G from Sumitomo, are an effective tool in the war on mosquitoes and fleas, targeting larvae as they moult.
Pest managers need to use a variety of tools to get on top of pest infestations. Professional flea treatments don’t just rely on an adulticide; insect growth regulators are included in the spray mix to target the other life stages. It’s the same for mosquito control.
Fogging can be an effective mosquito treatment, taking care of adult mosquitoes and treating their resting places. However, it does nothing to take care of the mosquito breeding sites, which means there is a ready supply of wrigglers waiting to develop into new adult mosquitoes (main picture, above). It is far more effective to control mosquitoes using larvicides than playing ‘catch up’ through later adulticide treatments.
To prevent mosquito problems, pest managers will always recommend that property owners eliminate areas of standing water – favoured mosquito breeding sites. However, owners are often not very co-operative in eliminating such sites, and sometimes it is not possible to eliminate all breeding sites due to access or sheer numbers. Treating these breeding sites with a suitable larvicide can have a significant impact on mosquito numbers.
For Audy Geiszler, from Audy Geiszler Pest Control in Bowen, Sumilarv G has transformed the way he has managed mosquito control at Abbot Point coal port in North Queensland.
“We’ve been managing mosquito problems at Abbot Point for a number of years,” Mr Geiszler said. The site is right in the middle of a wetland area with a lot of standing water, making it a real mosquito hotspot. Although the main problem is with saltmarsh mosquitoes, being a region that experiences Ross River fever and dengue outbreaks, the site’s environmental scientists are particular keen for us to keep on top of the mosquito problem.”
“Historically, we’ve carried out regular fogging treatments, but last year we started using the Sumilarv ‘teabags’ to target mosquito breeding sites,” Mr Geiszler explained.
Sumilarv G is a granular insecticide growth regulator, pre-dosed into 0.5g sachets (the ‘teabag’). According to Charles McClintock, Sumitomo Chemical business manager, the slow release granules kill the larvae as they moult. Even at the low doses, it provides four weeks of control.
“The pre-dosed sachets make it quick and easy to treat areas of standing water. We’re out on site once a month, so it’s good to know we are getting protection in between visits. From our observations, but also from the feedback from staff, it appears to have been quite effective in reducing the mosquito population. So much so, that it has reduced the amount of fogging we have carried out,” said Mr Geiszler.
Sumilarv G is active at levels as low as 0.1 parts per billion. This delivers two key benefits, Mr McClintock explains.
“Firstly, a single treatment can be very long lasting, with a high dose protecting a standing water source for as long as six months. Secondly, egg-laying females can transfer or auto-disseminate minute amounts of pyriproxyfen when they fly from one breeding site to another. With pyriproxyfen active at extremely low doses, this natural behaviour can move active to untreated or hard to access, adjoining breeding sites, magnifying its effect.1”
As a result of this success, Whitsunday Regional Council have started using Mr Geiszler to carry our further treatments across the council area. “It’s not possible or desirable to fog extensive areas for mosquitoes – being a mining area there is significant environmental focus on all activities. But by using Sumilarv G in standing water bodies, we can impact mosquito populations with a targeted treatment,” Mr Geiszler said.
For commercial and industrial, treating breeding sites is a key component of a successful mosquito control program, Mr McClintock advises.
“Even for residential mosquito treatments, using larvicide treatments to supplement fogging, will give superior results and that professional touch.”
1 Devine et al (2009). Using adult mosquitoes to transfer insecticides to Aedes aegypti larval habitats. Proceedings of the National Academy of Sciences 106 (28): 11530-11534