Blistering heatwave gives Japan respite from typical summer pest: the mosquito

Julian Ryall

Record temperatures across Japan this summer have caused dozens of deaths from heatstroke and left thousands more hospitalised.

Similarly, crops are withering, reservoirs are running dry and demand for energy to power air conditioning units has soared.

The good news, however, is that the heatwave has curtailed the activities of one of the most annoying staples of a Japanese summer: mosquitoes.

Research by scientists at the Institute of Pest Control Technology, in Chiba Prefecture, has shown that mosquitoes become far less active when temperatures rise above 35 degrees Celsius and are less inclined to seek out victims from whom to suck blood.

Conditions this year – with 927 Meteorological Agency stations across the nation reporting highs above 35 degrees on 3,127 occasions in July alone, up sharply from 812 in the same month last year – have been far from ideal for mosquitoes.

The town of Kumagaya, in Saitama Prefecture north of Tokyo, set a record high temperature for the whole of Japan in early August, reporting 41.1 degrees.

“Another significant factor will be the heat evaporating the pools of stagnant water where mosquito larvae grow,” said Kevin Short, a professor at the Tokyo University of Information Sciences.

How many more will have to die as Asia gets hotter?

Previous research by the Institute of Pest Control Technology has shown that people with blood type O are more likely to become the target of mosquitoes.

Yet Short warned that people should not let their guard against blood-sucking pests down, particularly as temperatures have dropped in recent days and there are likely to be more pools of standing water since Typhoon Jebi swept across the Japanese archipelago in the early part of the week.

“There are several species of mosquito in Japan, including a species comes out in the autumn and is relatively small – but seem to pack a more vicious bite,” he said.

“Those will be coming out soon and looking for hosts.”

This article Blistering heatwave gives Japan respite from typical summer pest: the mosquito first appeared on South China Morning Post

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