Although there are over 3,500 species of mosquitoes in the world, New Zealand currently only has 16 known species. Of these three are common nuisance pests to humans. These are Culex pervigilans and Culex quinquefasciatus (which are the annoying ones that buzz/whine around your head and bite you at night when you are sleeping), and Aedes notoscritpus the common black and white stripey mosquito that bites you during BBQ's or if you are doing work in shady areas. The rare native Opifex fuscus rock pool mosquito can also create a nuisance with a sturdy bite to those in coastal areas.

Luckily for us here in New Zealand mosquitoes mostly just pose an annoying nuisance with people reacting differently to their bites. Mosquitoes are not known to vector any human malaria, filarial worm, or economically significant arbo-viruses in New Zealand. However it is possible that New Zealand could experience an outbreak of one of these disabling or life threatening diseases. The human population in New Zealand is non-immune and susceptible to most arboviruses.

Potentially the most significant mosquito-borne diseases to New Zealand are the arboviral diseases Ross River Virus Disease (RRV), Dengue, Barmah Forest Virus Disease and Japanese Encephalitis. Yellow fever, malaria and filariasis warrant consideration, but are thought to present a much lower level of risk to New Zealand.

In New Zealand only Whataroa virus is associated with mosquitoes. Whataroa virus is an alphavirus and has been isolated from field samples of Culex pervigilans and Culiseta tonnoiri whereas other local species such as Opifex fuscus, Aedes notoscriptus, and Aedes australis have been shown to be competent vectors in the laboratory. Based on current scientific work undertaken by experts some of our mosquitoes can carry diseases. Let's hope the diseases do not become established here.

• Aedes notoscriptus is the primary suspected vector of Dog heartworm Dirofilaria immitis in Australia, can transmit Ross River Virus or epidemic polyarthritis (RRV) and is a vector of Murray Valley encephalitis virus.

• Aedes australis is a potential vector of RRV and also dog heartworm.

• Culex quinquefasciatus is the principal vector of Saint Louis encephalitis virus in the northern and western United States. It is also a vector of dog heartworm and vectors an occasional lung parasite in humans (Pulmonary dirofilariasis). Culex quinquefasciatus is a vector of human filariasis, Wuchereria bancrofti, both Sindbis and Kunjin viruses and also RRV has ben recorded during an outbreak in New Caledonia (during the 1979-80 Pacific outbreak). To a lesser extent Murray Valley encephalitis virus isolated from field collected specimens in northern West Australia and the species is suspected as being the principal vector for the American West Nile Virus, an important vector of fowl pox and possible vector of myxomatosis. Basically this mosquito is an important pest species world wide.

Legislation:

Section 29(q) of the Health Act 1956 states that a nuisance is deemed to be created where there is "any condition giving rise or capable of giving rise to the breeding of flies or mosquitoes...." It follows that subsequent sections of the Act apply to the extent that owners and occupiers are, in the first instance, responsible for abating such a nuisance. Exotic mosquitoes are covered under the Biosecurity Act 1993 and the International Health Regulations, and Biosecurity incursions are dealt with by the Ministry of Health and MAF Biosecurity New Zealand.

Mosquito Control - HELPFUL HINTS

• Don't leave water sitting in old containers.
• Unblock gutters.
• Bottoms of pot plants that hold water can have bleach added to make them less attractive.
• Don't have bamboo or bushes close to the house.
• Keep windows closed at night when lights are on.

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