WELLINGTON, Dec. 15 -- The Asian tiger mosquito, which can carry potentially deadly diseases such as malaria and dengue fever, is spreading rapidly through the small Pacific island nation of Tonga, a New Zealand researcher said Monday.

The Asian immigrant was "outcompeting" other local mosquitoes, said University of Canterbury researcher Tom Swan, who analyzed mosquito larvae from 88 sites on Tonga's main island of Tongatapu and offshore Eua island.

Although malaria was not present throughout Tonga, dengue fever was known to cause significant illness and death each year, said Swan, who was providing the data to Tonga's Ministry of Health.

"Nine species of mosquitoes were recorded in Tonga, including the virulent Asian tiger mosquito, only the second known occurrence of this mosquito in Tonga," Swan said in a statement.

The Asian tiger mosquito was a significant carrier for dengue fever and chikungunya virus, which both caused fevers, muscle pain and severe joint inflammation, and could be particularly fatal for the elderly and young.

"Initial assessment has shown that the Asian tiger mosquito appears to be outcompeting many of the established mosquitoes. This is of growing concern for the people of Tonga and may increase the presence of such mosquito-borne diseases in Tonga in the future," said Swan.

"A recent outbreak of chikungunya virus in April 2014 infected 10,000 Tongan residents, resulting in numerous fatalities. Car tires were the most common habitat from which mosquito larvae were collected," he said.

An increase in public awareness, reduction of larval habitats, such as car tires, and the production of a pictorial identification key were major outcomes to help reduce the spread of mosquito-borne diseases, said Swan.