Cold spring, heavy rain helped Alamosa mosquito district


ALAMOSA — With colder temperatures right around the corner, mosquito control can now hibernate until the spring. Alamosa Mosquito Control District Operations Manager Sarah Cantu summarized the season to Alamosa County Commissioners during their Wednesday meeting.

Though the district was busy, they saw fewer mosquitoes than normal due to the weather. Using 18 light and carbon dioxide traps, a total of 92,480 mosquitoes were caught and counted by hand.

“That sounds like a high number; however, that’s one of the lowest numbers we’ve ever had in history,” Cantu said. “We were down from last year when we counted nearly 200,000 mosquitoes.”

Cantu said that the chillier spring delayed the mosquitoes from coming out until June, while the unseasonably wet August helped control the adult population.

“They’re not going to want to be active when it’s cold and wet so they’re hunkering down in the grasses,” said Cantu. “You would think we would have more standing water and longer standing water with the extra rain, but it didn’t affect our larvicide operations whatsoever.”

Those caught mosquitoes were then tested for West Nile Virus and other transmittable diseases. The district found two positive West Nile sites from 772 samples that contain up to 50 mosquitoes each, one in August and another in July. Yet, there have been no human cases of the virus in Alamosa.

The samples were also tested for Western and Eastern equine encephalitis virus but there were no positive results. Of the 13 identified species in the 121 square mile district, none are known to carry Zika or Lyme disease.

Heavy evening winds, though, did cause a problem for control operations. If winds reach 10 mph then the adulticide can’t be sprayed from the fogging trucks or airplane. Of 37 attempted flights, only 16 were completed due to wind.

However, those winds forced the mosquitoes to not bother residents.

“If the wind is blowing they won’t want to be active,” said Cantu. “They’re going to hunker back down and not seek that blood meal.”

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