Mosquito mayhem keeps abatement crews buzzing
Unless you’ve managed to stay indoors these last few weeks, chances are you’ve felt the sting of mosquito mania on Daniel Island. The mad dash from the house to the mailbox and back to avoid prolonged exposure, the swarm of tiny black clouds around players and families on athletic fields, and leisurely walks that turn into sprints after multiple bites by the pesky predators. The local mosquito abatement militia is aware of our pain - and they have been working diligently to do something about it. But, as history often reminds us, Mother Nature can be a powerful foe. “Sometimes Mother Nature creates a perfect recipe for mosquito hatch-offs,” said Jeff Cary, Director of Berkeley County Mosquito Abatement. “And that’s what we have right now.” Many residents have taken to Facebook to express that this feels like “the worst year” in more than a decade for mosquitos on the island. There may be some truth to that, but according to Cary, every year stands alone. The season’s recent extreme high tides combined with plentiful rain and a vast dredge spoil area on the island’s southern tip have created ideal mosquito breeding conditions. “Spoil sites are the primary problem,” Cary said. “They generate tremendously more numbers than your salt marsh sites, but with the high tides and rain, we’re getting hatch offs from both the salt marsh and the spoil sites.” And those hatch-offs have been so frequent that Cary and his crews have had a hard time keeping up. Another hatch-off late in the week prompted a second aerial spray on Sunday. Berkeley County conducts abatement services for the residential areas of Daniel Island, Thomas Island and Clements Ferry Road, while Charleston County handles aerial spraying on the dredge spoil sites. The main components of Berkeley County’s “integrated pest management program” are inspection and surveillance; mosquito larvicide, which involves finding out where breeding sites are and treating the water; and adulticide, a truck application of an ultra low volume spray consisting of micron-sized droplets designed to kill the bugs on contact. The chemical Berkeley County uses for ground spraying by truck to combat mosquitoes is pyrethroid, a synthetic version of the pyrethrin found naturally in the chrysanthemum plant. The low toxicity product does not pose a risk to humans, said Cary. For aerial spraying (which is not conducted over residential areas), a chemical known as “naled,” an active ingredient in Dibrom Concentrate and Trumpet EC, is typically used. This product, administered at a low rate, is “highly effective and poses minimal exposure risks to people, animals and the environment,” according to information provided to The Daniel Island News by Charleston County Mosquito Control. A low-flying spray plane was observed by several families last Thursday night as they gathered on an athletic field behind the Daniel Island School, as well as on fields utilized by the Daniel Island Soccer Academy. A resident sent an email to The Daniel Island News expressing concerns about the “manner and timing of how the airplane was flying.” According to Berkeley County Councilman Josh Whitley, the plane did not belong to Berkeley County. “We go to great lengths to do it at a time that is least impactful,” he said. “Which is weekends at daybreak. We were supposed to fly last Saturday and we pushed it back to Sunday because of the (9/11 Heroes Run) race. We are very cognizant of that.” Charleston County Mosquito Control Manager Frank Carson did not witness the incident in question, but said that aerial spraying conducted on that particular evening was done over the dredge disposal sites by a contractor they have used many times over the years with experienced pilots. He stated that he did hear from one resident who voiced a complaint about a spray plane flying over island soccer fields. Her concerns were relayed to the contractor, he added, and will be evaluated to see if any changes need to be made in the future. “This summer has been unusual,” Carson said. “We’ve had to do aerial spraying for adult mosquitoes four times this year in the Charleston Harbor area, which is more than double the norm. When they fly, they have to go in patterns so they get coverage…and they have to go low enough so we don’t get overspray into areas that are not intended.” When it comes to residential and commercial areas on Daniel Island and the Cainhoy Peninsula, Cary and his team remain focused on attacking the mosquito problem as best they can. When he recently came out to do “landing count rates” in the community, his results varied widely. “Landing rate counts on Daniel Island were ranging between lows of zero in certain areas…to over 10 per minute with some substantially higher,” he said. “In some areas we had over 25 a minute…That’s why we decided to elevate from controlling with a spray truck to putting up an aircraft, because aircraft can reach outside of just the roads.” After a recent Saturday spraying, he decided to grab his bike and drive down to the island so he could ride around to do his own assessments. Victory, he discovered, can be short lived. “I spent four hours on the island,” he said. “I carried my bike down there and just rode the trails. I stopped 16 times and did landing rates and was very pleased with the results…But then I came in Tuesday and found out we had another (hatch-off) explosion. It’s very upsetting from our standpoint because we think we’re doing everything we can and you turn around and they’re back in full force.” And if you really want to understand the scope and magnitude of the problem - just do the math. Dredge sites can produce about 40 million mosquitoes per acre, said Cary, per significant rainfall. “When you look at the tip of Daniel Island, that’s about 1000 acres of dredge spoil disposal, and Clouter Creek (off Thomas Island) has about 1800 acres….Dredge sites will dry out after they flood and will form these giant fissures, or cracks, and they lay eggs in the cracks. In another rainfall the cracks are filled, and that’s why they literally come out by the billions.” Cary is hopeful that between his department’s efforts and more favorable weather conditions, the problem can be kept from getting worse. “If we can keep the rainfall down…as temperatures drop it will take longer between life cycles and they are less likely to hatch off as things get colder…I’m praying for a freeze.” For additional information on the BCMAP, as well as spray schedules and zones, visit their website at www.berkeleycountysc.gov/drupal/mosquito.