Tyson staff featured on local news

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Mar 29, 2019

Polar vortex did not kill of St. Louis mosquitoes, researchers say

By Jeff Bernthal

EUREKA, Mo. – Researchers at Washington University’s Tyson Research Center in Eureka say you might be disappointed if you thought this past winter’s sub-zero temperatures would minimize the number of mosquitoes in your backyard this summer.

Researchers have been monitoring buckets of rainwater placed in the center’s woods. They’ve placed leaves in the buckets to replicate a similar environment found in the St. Louis area. Researchers showed those buckets on Friday and there were day-old mosquitoes that hatched in the buckets.

“They are such a resilient group of insects that even when their numbers are just really hammered, they lay a ton of eggs and if a few of those eggs can make it through, they will make it through the next season,” said Tyson Research Center Director Kim Medley.

She said mosquito populations are susceptible to extreme cold but even if their numbers are reduced, they can make up for the reduction.

“They lay a ton of eggs and if a few of those eggs can make it through, they will make it through the next season,” she said.

Researchers have also found the eggs from the Asian Tiger mosquito, the type of mosquito common in the St. Louis area, have adapted to the cold.

“It only takes a couple of weeks under the right conditions for those hatched eggs to turn into adults,” said Medley.

The research into the effect of temperatures on mosquitos is only one part of mosquito research taking place at Tyson. Researches are also looking into other areas, including why certain types of mosquitos thrive in urban areas opposed to rural ones.

Communities will be able to use the research to determine the best possible ways to control mosquito populations.