(123rf)

Amid a relentless heat wave sweeping across South Korea, Seoul has seen a significant surge in mosquito populations over the past two weeks, turning a seasonal nuisance into a widespread concern.

According to the Seoul Mosquito Forecast System, the average mosquito activity index in the capital city has increased to its highest level of 100, in its four-tier system, for two consecutive weeks from June 2.

The highest level, "unpleasant," means outdoor mosquito larval habitats are formed from 50 to 100 percent. It is also defined when five to 10 mosquitoes are seen penetrating indoors at night in areas where the concentration of detached housing is high or one gets more than five mosquito bites during an outdoor activity at nighttime assuming that the subject remains in one place for 10 to 15 minutes.

During the same period a year ago, the mosquito activity index averaged at 65.6.

"Unlike last year, it has been raining heavily since early spring and the temperature has remained high, which has created conditions for mosquitoes to live in puddles and other places early on," said a professor in charge of mosquito forecasting in Seoul.

"The high temperature has also allowed the larvae to grow rapidly, allowing the number of adult mosquitoes to increase," he added.