The Mosquito Research & Control Unit (MRCU) would like the public to expect a higher than normal population of swamp mosquitoes next week due to the recent rains and higher than normal tide levels.

MRCU Director Dr. William Petrie asked for the public patience, “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 over the last few months and are now at a level that produces flooding in the swamps. Tidal fluctuations plus a recent rainfall event have led to favorable breeding conditions for the swamp mosquito. The swamp mosquitoes (Aedes taeniorhynchus) lay eggs in the swamp mud which may survive in a dormant state for long periods of time. Rainfall and tidal increases inundate the eggs which hatch into larvae very quickly. 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 couple of days. The female mosquitoes, which do bite and become a nuisance to the public, can survive for up to 15 days. The females seek blood for egg production and will lay numerous eggs back onto the swamp mud.

MRCU has a proactive surveillance program that monitors the swamps for favorable breeding conditions and the presence of mosquito larvae. MRCU operational staff are prepared to deal with a mosquito emergence utilising a fleet of truck-mounted foggers and the customized spray plane. The Aedes taeniorhynchus mosquitoes migrate into residential areas during the evening after sunset and the early morning before sunrise. Truck-mounted fogging and aerial spraying target the Aedes taeniorhynchus mosquitoes during these high activity periods when the female mosquitoes are seeking a blood meal and biting ferociously.

MRCU will be monitoring the emergence closely and scheduling appropriate island-wide control activities during the week and into the weekend. For any questions or to report high levels of nuisance biting in your residential area contact MRCU on 949-2557.