Rising menace of Culex mosquitoes, threats they bear and what Delhi MCDs are doing about it

As the mercury level started soaring in Delhi from mid-March, Culex or house mosquitoes swarmed back in large numbers causing much inconvenience to Delhiites. Resident welfare associations have expressed their concern to the municipal corporation coercing them to call for or a high-level meeting to dig deep into the matter and find out measures to control their growth. From using mosquito larvicidal oil to house-inspections, the Delhi Municipality Corporations are picking on all kinds of necessary means to curb their menace.

Here’s why culex mosquitoes draw concern and challenges faced by the MCDs to curb their growth

Culex mosquitoes and why there’s a need to worry

Culex are found mostly in the floodplains of South and East Delhi as these areas provide them with the ideal condition to breed and multiply. They can fly up to 1 to 1.5 km in distance and are notorious for being host to some serious disease-causing germs.

Most vulnerable breeding grounds for Culex in Delhi

The hotspots for the Culex species in NDMC are Kushal drain and the border areas at Bharti Nagar and Bapa Nagar. Their menace is also noticed in areas near the Yamuna flood plain, North by Najafgarh drain and South by Barapullah drain. Culex mosquitoes breed in dirty and stagnant water

Diseases caused by Culex mosquitoes and weather conditions apt for their growth

Culex are the carriers of germs causing Japanese encephalitis, a life-threatening viral disease that causes inflammation in the brain.

Medical health officer with East MCD Dr Som Shekhar told the Indian Express, Culex breeds in the depressions in the flood plain where water gets stagnant after receding during the summer season. The ideal temperature for the mosquitoes to breed is between 10 degrees Celsius to 40 degree Celsius. Hence the March-April is the ideal time to speed culling the mosquito growth drive.

How the civic bodies are responding

According to a senior official from the public health department of the EDMC, the municipality is putting mosquito larvicidal oil-coated blocks in the breeding grounds that creates a layer that the mosquitoes cannot evade. Underground Insecticide fogging is also being done to paralyse the mosquitoes, said Dr R N Singh, senior chief medical officer of NDMC. South and North Municipalities are also following the same procedure.

What are the mosquitoes still multiplying and challenges faced by MCDs?

Even with MCD officials are continuously inspecting households with open defecation and providing favourable weather conditions, the number of mosquitoes has seen a sharp rise in the past few weeks. Debanad Sharma, president of, Anti-Malaria Ekta Karamchari Union said that the workers are monitoring houses, doing tax survey and encouraging people in unauthorised colonies to register their houses. However, sources said 1,000 works have been diverted from their inspection duties and house visits gave declined from 44 lakh in 2018 to 21 lakh this year till March second week. The numbers dipped massively in 2020 due to the pandemic as workers were utilized to perform Covid-related duties.

On a usual day, near to 3,500 workers visit 60 to 70 Delhi homes to inspect coolers, tanks surrounding to find they have stagnant water or other favourable breeding ground in their surroundings.