Pest mosquito eliminated from Kaipara

29 August 2008

MAF Biosecurity New Zealand (MAFBNZ) has successfully eliminated the Southern salt marsh mosquito (SSM) from the Kaipara area, ending some six years of treatment and surveillance activity.

The Australian mosquito can be a carrier of Ross River virus, which causes a severe flu-like illness in humans and is also a vicious day time biter.

The insect was first detected in Napier in 1998 and has been under treatment at several locations around New Zealand since then. It has now been eliminated from most of these sites.

SSM was first detected in the Kaipara in 2002. Activities undertaken since then to locally eliminate the insect have included helicopter and ground treatment operations, trapping of adults, and sampling for juvenile life stages.

During the eradication programme, both the Northern and Southern Kaipara Harbours were treated with S-methoprene insecticide granules and Bti (Bacillus thuringiensis israelensis) spray where live larvae were found.

MAFBNZ Incursion Response Manager David Yard says the successful elimination of the mosquito in Kaipara is something to celebrate, now that two years have passed without any sign of the insect - as adults, larvae or eggs. There has been intensive surveillance undertaken during those two years for both adults and larvae.

“MAFBNZ, and in the initial stages, the Ministry of Health, have undertaken a comprehensive work programme against this aggressive mosquito and to be able to declare this success is significant considering the vast areas of ideal habitat the Kaipara provides for the pest,” Mr Yard says.

As well as the Kaipara, MAFBNZ is also declaring localised elimination of the SSM in the Grassmere area in Marlborough. The area of salt marsh habitat around the salt works and associated evaporation ponds has also been free of any sign of the mosquito for two years.

Now elimination has been declared in Kaipara and Grassmere, MAFBNZ hands these areas to the Ministry of Health which administers an active surveillance programme around the entire New Zealand coast line to provide early detection of any exotic salt marsh mosquito. It is important that a sound level of ongoing inspection is carried out in these areas.

The active eradication programme for SSM is continuing in two remaining locations nationally - Coromandel and Wairau (in Marlborough) with excellent progress being made.


For further information, contact:

Lesley Patston | Senior Communications Advisor | Ph 04 894 0163 or 029 894 0163

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