Mosquitoes

Mosquitoes should be controlled because they are known to transmit communicable diseases that may threaten human health and life. They are also a nuisance that causes adverse impact on one’s quality of life. New Zealand and international organisations have legislation that aims to protect public health.

There are 16 species of mosquitoes settled in New Zealand although some of them originated in other countries. The Auckland region has 1500 kilometres of coastline, is home to two seaports, one major international airport, a military airport, a naval base and sugar company wharves, all of which provide portals for xenobiotic threats to health. Mosquitoes are the most important group of bloodsucking insects that lead to nuisance and spread diseases to humans and other warm-blooded animals.  They can transmit Dengue fever, Ross River virus, Yellow fever, malaria, West Nile virus, dog heartworm and Japanese Encephalitis.

The New Zealand Government and the World Health Organization (WHO) have issued a series of legislation.  Listed below are some principal laws and regulations and their sources for your information.

Some useful pamphlets for mosquito response are available online from the HealthEd webpages of the NZ Ministry of Health:

The Auckland Regional Public Health Biosecurity Team was formed to undertake routine mosquito surveillance programmes, carry out mosquito audit surveys at the mosquito main gateways such as Ports of Auckland, Auckland International Airport and Royal New Zealand Airforce at Whenuapai, on a regular basis, respond to exotic mosquito interception and/or incursion reported, and answer and process public complaints regarding mosquito issues in the Auckland region.

The Environmental Health team was involved in the incursion and delimiting work surrounding the discovery of the exotic Southern Saltmarsh mosquito Ochlerotatus camptorhynchus in the Kaipara Harbour early in 2001.  However, the surveillance of Southern Saltmarsh mosquitoes was handed over to Biosecurity New Zealand under the Ministry of Agriculture and Forestry in late 2005.

Southern Saltmarsh Mosquitoes

The Southern Saltmarsh Mosquito Ochlerotatus camptorhynchus has been under enhanced surveillance throughout New Zealand since incursions occurred in the Hawkes Bay. The first finding was in Napier, December 1998. Further findings occurred in Gisborne in October 2000 and in Porangahau and Maungawahio Lagoon several weeks later. The mosquito was discovered in the Kaipara Harbour early in 2001 by Regional Public Health staff conducting routine surveillance. As well as being a nuisance biter, the mosquito is a potential vector for Ross River Virus disease. Ochlerotatus camptorhynchus is a saltmarsh mosquito whose larvae rely on saline water for survival. Heavy rainfall and or high tides after a period of dry weather are known to activate eggs laid earlier in the year. Surveillance work is frequently conducted following rainfall or very high tides as this mosquito’s eggs can survive up to nine months.

Symptoms of Ross River Virus

There may be a transient rash and mild illness with fever, or the joints, particularly the ankles, fingers, knees and wrists may be affected with polyarthritis. 

In some people Ross River Virus disease may cause no symptoms. The symptoms of Ross River Virus disease become evident 3-21 days after infection. Mild cases may recover in less than one month but many other patients have problems that persist for many months and years.

Aedes aegypti

Aedes aegypti (commonly named Asian tiger mosquito) is one of the important exotic species to control. It can host yellow fever and Dengue fever viruses.  It has the following features when biting human beings:

  • Although it may feed at any time, the mosquito bites humans only between a few hours after dawn till an hour or so after sunset.
  • The mosquito's preferred breeding areas are in stagnant water, such as flower vases, uncovered barrels, buckets, and discarded tires, but the most dangerous areas are wet shower floors and toilet bowls, as they allow the mosquitoes to breed right in the residence.

When you have any concern or enquiry on mosquitoes, please phone our 24/7 operational number (09) 623 4600 (Environmental Health) if you are in Auckland; otherwise you may ring the toll-free Mosquito Hotline number 0800 Mossie (0800 66 99 43) from anywhere in New Zealand.