Q: A recent letter to the Gabber and other recent comments have brought up the noticeably bad mosquito problem this year. Long-term residents have pointed out that there was once a mosquito-control program involving weekly spraying. When was this program discontinued, and why? Was it because of budgetary constraints or health and environmental issues regarding the pesticides that were used? What pesticides were used, and what were the possible side effects on humans and beneficial insects? Would the city consider reinstating the program?
A: The county did not discontinue the program.
"Unfortunately, the work we're doing, we're in and out, no one hears it, so they think nothing is being done," Cort Milne, who works with Pinellas County Mosquito Control says. "Just because they don't see a fogging truck or hear it in the early morning doesn't mean we're not doing anything to control the mosquitoes."
Pinellas County, not the city, handles mosquito control. They have 12 techs who travel to every part of the county, including Gulfport, and they use a variety of treatment methods – including the fogger trucks – to control mosquitoes. According to the county's Mosquito Control, spraying amounts to roughly 25% of how the county fights mosquitoes and remains one of the least effective methods. They also use liquids, tablets, and granular materials, as well as Gambusia, or mosquito fish, that eat larvae.
Mosquito Control also puts out mosquito traps. Every area has an average amount of mosquitoes trapped, from zero to 100, and when the county sees an increase of more than 25 mosquitoes in a trap (over a few days), they will send in fogging trucks. However, they prefer to kill the larvae before they hatch.
"Most of our efforts are trying to find them in the water before they become adults," Jason Stuck, Acting District Operations Manager for Pinellas County Mosquito Control, says. "If we can find them before they become adults, then the disease transmission will be lower. We try to get them while they're in the water, as larvae, before they hatch into adults."
The fog trucks use either Duet or Biomist, although Stuck stresses that the county bases their program on "trying to find them before they become adults. Most people, that's what they don't understand – they just know the fogging trucks because of the loud noise and the stuff squirting out the back," he said.
Biomist contains permethrin, which falls below the EPA's "level of concern" for humans when used outdoors but is "highly toxic" to anything living in the water, be it fresh or salt water, according to the EPA.
Duet contains pyrethroid, a synthetic form of chemicals produced in chrysanthemums. The EPA says they do not pose any risks to children or adults but will kill fish and honeybees. In addition, the EPA prohibits directly applying pyrethroid to open water or within 100 feet of lakes, streams, rivers or bays. It also limits spraying to early in the day or late in the evening "to reduce the potential for exposure to animals, such as bees, that are active during the day."
Stuck also says that the larvicides and in-water efforts to exterminate mosquito larvae prove far more effective than fogging trucks. Despite limited effectiveness and the environmental compromises of using Duet and Biomist, in certain cases, the county will use these methods.
As of right now, he says, there's nothing scheduled to be fogged in Pinellas County. This results from the lack of virus activity in sentinel chickens and trap counts not high enough to generate a need for fogging. Sentinel chickens – eight coops of seven chickens each – have not shown any signs of mosquito-borne viruses. Mosquito control keeps these coops throughout the county; the sentinel chicken closest to Gulfport lives at Boyd Hill Nature Park.
The spray from the fogging trucks, he says, only attracts adult mosquitoes and only works until sunrise, which is why Stuck says his department concentrates on finding standing water.