Nature has more on a Tahitian lab’s plan to use Wolbachia bacteria to wipe out mosquitoes:
The mosquito problem could be solved in the Society Islands — a part of French Polynesia that includes Tahiti, Moorea, Bora Bora, Huahine and Raiatea — within ten years, says Hervé Bossin, an entomologist at the mosquito lab of the Louis Malardé Institute in Paea, Tahiti, and the project’s lead scientist.
He and his team plan to do this using a technique that infects mosquitoes with a specific strain of a bacterium called Wolbachia. About 65% of insects around the world carry Wolbachia, but the strains vary. If mosquitoes with different strains mate, the resulting eggs develop incorrectly and don’t hatch. If there are enough of these doomed pairings, an area’s mosquito population usually dies out.
But first, scientists must sort the males from the females. In a small, tidy lab on Tahiti’s east coast, nestled among coconut palms and fragrant white tiare blossoms, senior technician Michel Cheong Sang pours water between two glass plates set at an angle, washing several dozen larvae of Aedes polynesiensis mosquitoes down between them. The larger females get stuck about halfway down. The smaller males descend a bit farther, forming a dark, wriggling band behind the glass. The low-tech method sorts more than 99% of the larvae correctly, says Bossin.
All the larvae are infected with a particular strain of Wolbachia — taken from a related mosquito species, Aedes reversi — that is not naturally present in French Polynesia. Only the males will be released in target areas to mate with wild female mosquitoes.
Researchers have run similar trials in Brazil and in the United States, where three states saw populations of wild A. albopictus reduce by 70% over three years.
The Wolbachia approach is based on a naturally occurring bacterium, and has drawn less opposition than experimental methods that use genetically modified mosquitoes.
Bossin and his team started their first large-scale study in 2015, on a tiny island in the atoll of Tetiaroa. The atoll, once owned by film star Marlon Brando, is a 20-minute flight from Tahiti. The researchers’ monitoring efforts currently find about one female per trap per week. Last year, earlier in the project, they found one per trap per day.