Sterile male insects are the new weapon to combat their growing numbers

If the Chennai Corporation has its way, an army of male mosquitoes will soon spell doom for their own species in Chennai.

The civic body on Monday shortlisted a technology to grow sterile male mosquitoes to support its mosquito control operations without harming the environment. The technology was shortlisted after screening 23 proposals made by private agencies.

The civic body will soon commission specially designed glass houses to grow such sterile male mosquitoes of different species in neighbourhoods.

“The glass houses are likely to have a dimension of 20 feet by 100 feet. A minimum of one lakh mosquitoes can be grown out of which 40 per cent may be male. The females will be separated by attracting them using male pheromones and then, killed. The male mosquitoes will be subjected to gamma radiation of appropriate dosage to make them sterile. The sterile male will be introduced in neighbourhoods with high mosquito density,” said B.M. Rex, entomologist, Spartan Enterprises, which is one of the consultants for the project.

The female mosquitoes that breed in such neighbourhoods will lay infertile eggs. After the female lays eggs, it dies; the infertile eggs will not to hatch. This will lead to reduction in the number of mosquitoes.

The civic body is planning to tweak this technique in such a way that its sterile male mosquitoes will be able to successfully compete with existing normal male mosquitoes. The challenges such as exorbitant cost in procurement of pheromones to separate male from female, Atomic Energy Regulatory Board clearance in commissioning equipment for emitting gamma radiation and trained manpower will be overcome by the civic body by a specially chalked out strategy. The existing fogging operations will continue to be carried out by the civic body for mosquito control.

The Chennai Corporation had, asked private companies to shoulder the responsibility of mosquito control operations in the city. The decision was taken following a rise in mosquito menace.

The companies had their first meeting with the city health officer in September based on which the technology has been shortlisted. Residents in many added areas have been reporting severe mosquito menace.

The challenges caused by breeding grounds in over 25,000 unoccupied plots of land, two lakh overhead tanks, 74,526 wells, 65,166 sumps and 1,300 km of stormwater drains are likely to be tackled through the collective effort of such private entities.