Rainy season signals spraying

The annual aerial assault on mosquitoes is set to begin.

As a result of heavy rainfall on Monday and Tuesday, the low-flying airplanes of the Mosquito Research and Control Unit will once again take to the air.

The control campaign is targeted at the Aedes Aegypti mosquito, which can carry the dengue fever. It mostly breeds in urban areas, hence the reason the spraying will be carried out in George Town and West Bay, the two main population centres of Grand Cayman.

MRCU Assistant Director Alan Wheeler said aerial operations concentrating on George Town will commence early Friday, dependent on weather conditions.
“Flights will continue for several weeks, starting approximately at 6pm every night,” he said.

The Aedes Aegypti mosquito numbers are expected to increase with the start of the rainy season, and Mr. Wheeler explained why this mosquito is particularly troublesome from a control standpoint.

“This mosquito can be a problem to control because it has resistant eggs, which can live outside water,” he said. “In fact a lot of the mosquitoes we are now seeing are eggs that were laid at the end of the last season. They are able to stay dormant for two years in some cases.”

He explained that the mosquito is endemic to Africa and was found only there for a long time but, “because of the trade and especially used tires and things like that, they have spread all over the world.”

Dr. Wheeler added that the fact that a lot of Aedes Aegypti mosquito eggs had hatched now means that if we could impact them at this point, it would bode well for the rest of the season as well as for next year.

“Although dengue is not endemic in the Cayman Islands, the population of this mosquito needs to be minimised and there is always the possibility of travellers introducing the virus into the Islands,” he said.

The public can help the MRCU in its control efforts against Aedes Aegypti mosquitoes by keeping their yards free from any containers where rainwater can accumulate. The Aedes Aegypti mosquito is commonly found breeding in water drums, buckets, discarded care tires and any other vessel capable of holding water.

With regard to the mosquito genetic modification programme, Mr. Wheeler it was simply a research endeavour and not a part of everyday control at this juncture, though he said the method could be employed later in the season.