LOCAL

AgCenter launches largest mosquito survey since 1980s

Ashley Mott
The News Star

A mosquito survey underway across Louisiana will compile data regarding the population of container mosquitoes statewide.

Kristen Healy, assistant professor with the entomology department at LSU, hopes this year's project will be the start of a larger effort. 

"This year we were fortunate we were able to get the boots on the ground and volunteers in each of the 64 parishes, which was huge," Healy said. "The goal is to sample throughout the summer. ... We are letting the data take us where it leads us."

Shannon Rider, director of the Ouachita Parish Mosquito Abatement District, said a plastic cup holding water, preferably obtained from a nearby source, is left at each surveillance site — there are multiple surveillance locations in each parish — with a piece of paper in it.

The paper is labeled with the site number and partially submerged to create a surface for mosquito eggs to latch. 

Volunteers will return to the cup and retrieve the paper after several days, and the eggs and paper are shipped to the LSU AgCenter in Baton Rouge. The mosquito species are then determined by a DNA test, the most efficient method of identification. 

The information can be key for determining where certain mosquito species live, particularly those that can be vectors for diseases such as Zika, Chikungunya and yellow fever. 

Shannon Rider displays a trap that will collect mosquito eggs for a statewide survey.

"We don't have a lot of information throughout the state," Healy said. "Shannon's parish (Ouachita), they have historically done a lot of surveillance and know a lot of what their mosquito populations are like. But there really hasn't been a comprehensive statewide survey with every parish involved looking at what our container mosquito species look like, what our species distribution is and whether we have certain species." 

The traps contain water and  a paper the mosquito eggs attach to. The paper is shipped to Baton Rouge, where the LSU AgCenter hatches them to identify the mosquito types collected.

The last comprehensive mosquito survey conducted in Louisiana followed the introduction of Asian tiger mosquitoes in the mid-1980s. Increases in surveillance can follow the introduction of new species and new diseases. 

The surveillance program underway started as a proposal to the Centers for Disease Control submitted by the Department of Health on behalf of LSU AgCenter. Tulane University and the Louisiana Mosquito Control Association are also participating. 

"Because there are not a lot of mosquito control programs in a lot of the parishes, we don't have much data and you know a lot of these container . . . mosquitoes, they are potential vectors for a lot of these new and emerging threats, the Zika virus, for example," Healy said. 

Each surveillance location is recorded and tracked throughout the 15 week survey.

In Ouachita, surveillance for aedes genus mosquitoes has been underway previously, particularly for the aedes aegypti, the primary vector of the Zika virus.

In 2016, the district used mason jars painted black and filled with water to serve as a collection device. A paint stirrer was placed in the jar to create a prime environment for gravid, or pregnant, mosquitoes, to lay their eggs. 

Rider said that the new process puts the entire state on the same page, and that a list of protocols and procedures provides guidance for the surveillance process. 

The 2017 project is expected to conclude in early September, after 15 weeks of collection.

"I don’t know if we will detect anything new or different," Healy said. "It’s still early in the process, but this might lead to new areas we want to focus on and think about protecting the public more or put more money toward mosquito control programs in areas that may have greater risk factors we weren’t really aware of."