Officials in Grand Cayman are forecasting higher than normal levels of swamp mosquitos as recent rains and higher tides will likely offer a temporary boost to the population of blood suckers.
The Mosquito Research & Control Unit has issued a public advisory for local residents to expect elevated numbers of swamp mosquitos for the next few weeks due to excess levels of moisture and water leading to more favourable breeding conditions.
Dr. William Petrie, director of the mosquito research and control programme in the Cayman Islands, said, “Staff are prepared to deal with the issue, but at the same time we want to advise residents on Grand Cayman to expect a higher presence of mosquitoes for the next week or so.”
Tides in Grand Cayman have been rising during the last few months and are at a level that produces flooding in the swamps. Tidal fluctuations plus recent rainfall have led to favourable breeding conditions for the swamp mosquito. The swamp mosquitoes lay eggs in the swamp mud, which may survive in a dormant state for long periods.
Rainfall and tidal increases inundate the eggs, which quickly hatch into larvae. Larvae will feed and grow, and within 7 to 10 days pupate and emerge as adult mosquitoes. The male mosquitoes do not bite and only survive for a few days. The female mosquitoes, which do bite and become a nuisance to the public, can survive for as long as two weeks. The females seek blood for egg production and will lay eggs in the swamp mud.
The mosquito control programme has a proactive surveillance initiative that monitors the swamps for favourable breeding conditions and the presence of mosquito larvae. Operational staff deal with a mosquito emergence by utilising a fleet of truck-mounted foggers and a customised spray airplane.
The mosquitoes migrate into residential areas after sunset and during the early morning before sunrise. Truck-mounted fogging and aerial spraying target the mosquitoes during these high activity periods.
Officials will be monitoring the emergence closely and scheduling appropriate control activities throughout Grand Cayman during the week and into the weekend.