Combating mosquitoes by land and air
During the offseason, you prepare to face your enemy. For Jefferson County Mosquito Control, that enemy is West Nile Virus and other mosquito – borne illnesses.
There were 1,878 human cases of West Nile in 2012, including 89 deaths, according to statistics by the Texas Department of State Health Services (DSHS). Of these cases, there were four cases of West Nile neuroinvasive disease (WNND) and six cases of West Nile fever (WN fever) confirmed in Jefferson County and two cases of WN fever were confirmed in Orange County, the department’s website states.
According to DSHS, “there are two forms of the illness — West Nile neuroinvasive disease and West Nile fever. The symptoms of severe infection from West Nile neuroinvasive disease include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. West Nile fever is the milder form of the illness, with symptoms including fever, headache, body aches, and occasionally a skin rash on the trunk of the body and swollen lymph glands.”
With the mosquito season nearly upon us, and the possibility of a West Nile outbreak looming, Kevin Sexton, director of the Jefferson County Mosquito Control District (JCMCD), said that there are many things that a mosquito control department has to do during the offseason to prepare.
“We go through all of our trucks — the chemical lines and units themselves — and see if anything needs replacing,” Sexton said.
The county has eight trucks — six are modified with dual steering for its daytime larvicide program, which targets disease-carrying mosquitoes by spraying catch basins and storm drains, attempting to kill the larvae.
In addition to their land fleet, JCMCD takes to the air to combat the bloodsuckers.
“There is required maintenance we have to do on our airplanes, and the King Air is a very complicated machine,” Sexton said. “That’s what we are mainly doing in the winter season — especially from January through March.”
JCMCD’s King Air plane, which has been in operation for five years, according to Sexton, is crucial to the operation.
“When big populations of mosquitoes come in after heavy rains and the trucks are having a hard time keeping up, the King Air (plane that covers the incorporated area) can cover a lot of ground quick,” he said. “We don’t use it near as often as the Agwagons (planes that cover the unincorporated areas), but when we need it, it’s there. The King Air uses a pyrethroid water-based chemical. We can load two loads on it and stay up in the air for an hour and a half. It has no odor. You hardly see it when it comes out. It’s a quick kill and is very effective on the West Nile breeding mosquitoes. When we have a positive pool of mosquitoes reported, we’ll put the King Air in that area.”
Jerry Hinson, chief pilot/supervisor for JCMCD, has worked for the county for 25 years training JCMCD pilots. The county currently has three pilots, Hinson said.
“The King Air is the only one that has a waiver through the FAA to fly over the public at low altitudes and disperse the (pyrethroid) chemical. EPA only allows us to spray two ounces of the chemical per acre. It’s a very safe product,” Hinson said.
The Agwagons, which spray over the suburban and rural areas of Jefferson County, use a Malathion chemical. Neither the pyrethroid chemical nor the Malathion leaves residue in the environment, Hinson said.
“We put that out at two ounces an acre, also,” he said. “That’s like a shot glass for a whole acre. It has to touch the mosquito to kill it.”
Jefferson County has about 70 spray areas that cover around 1,100 square miles and there is a tight window of opportunity to spray, Hinson said.
“We have to go out and spray early morning or late evening,” he said. “We can’t spray in the middle of the day because the heat on the ground makes the chemical rise and it won’t come down. Another thing is the winds increase as the day gets later, and it spreads those chemicals places outside our target area, which we don’t want.”
Hinson said that JCMCD doesn’t spray the marsh areas because mosquito larvae are an important food for the crab and fish populations.
April generally kicks off mosquito season, and in order to be ready, Jefferson County hires seasonal employees specifically for the mosquito control district, Sexton said.
“We try to get everybody hired by the beginning or middle of April,” he said. “All of our drivers at night are seasonal employees except our night foreman. In the daytime, we have three full-time employees and three seasonal employees that work during the day doing the larvicide (a chemical used to kill larval pests), and then my full-time guys are some of my inspectors that get counts.”
All this costs a lot of money but, according to Sexton, Jefferson County Commissioner’s Court has always been supportive of the department.
“Whatever we may need is quickly addressed,” he said.
Sexton said he doesn’t anticipate a spike in chemical or fuel prices, and he said JCMCD’s budget has flexibility as well.
“Mosquito control is in great shape as far as the budget is concerned,” he said. “I try to anticipate what kind of season we may have for the next budget year based on the current year, but it is strictly an estimate. There is no way of determining what the mosquito populations may be like for the upcoming season.”
Sexton said that the West Nile season generally starts when the weather starts warming up and stays warm.
“Right now we’re getting these cold fronts, which is very unusual,” he said. “As long as we are getting this cool weather, it is probably not going to be a big factor at this time. But as soon as it warms up and stays warm, that’s generally when West Nile will show up. Last year, the first time we got a positive pool of mosquitoes was in June. We begin collecting (for West Nile testing) in May.”
After the cold weather subsides, JCMCD will begin spraying at night before they begin spraying during the day, Sexton said. The district will begin with preventative treatment for the hatching of larvae and is asking residents to help combat the pests as well.
“The residents themselves can help out by keeping the water at a minimum,” Sexton said. “Empty out dog dishes and bird baths every three to four days. It takes about five days for a mosquito to go from egg to adult. If they keep emptying the water out, (the mosquitoes) are never going to make it to adulthood.”
And if a wave of mosquitoes makes its way in from the marshes, Sexton said that JCMCD’s planes and trucks would be ready to attack the problem.
“Our job is to give the citizens of Jefferson County the best relief possible from mosquitoes in the most cost efficient way we can,” Sexton said. “We cannot eliminate all mosquitoes, but we do try to keep them from negatively affecting the quality of life that the public expects. I believe with a dedicated staff and the tools and equipment, we have to work with, we meet that goal.”
For more information, visit www.co.jefferson.tx.us/jcmcd/summary.htm.
Kevin King can be reached at (409) 832-1400, ext. 225, or by e-mail at kevin [at] theexaminer [dot] com.