Nagar Bhaban sources said they need 200 litres of adulticides each day for the anti-mosquito drive while they have only 3,200 litres in stock.

"We will be able to continue the mosquito control drive for next two weeks. I don't know what will happen after that," said an official at the DCC health department.

Due to the lack of adequate adulticides, the DCC is conducting the drive only in the VIP areas, sources said.

Mosquito menace has increased to such an extent that the insects bite not only at night but also at daytime, city residents alleged. HSC examinees are the worst victims.

DCC this year increased the allocation for mosquito control, surveillance and monitoring by Tk 3 crore from last year's Tk12 crore. But the process of purchasing insecticides was hampered as the tender was cancelled for three times.

DCC floated the tender for purchasing 50,000 litres of adulticides in the middle of last year but cancelled the bids for some lapses found in the bid documents.

"It will take a month to give work order to the selected bidder and two months more to import the insecticides," the DCC official said.

DCC uses both larvaecides and adulticides to control mosquito. Larvaecide is used to stop breeding of mosquito while adulticides for killing flying mosquitoes.

"We have enough larvicides to fight the mosquito breeding. In fact, adulticide is not effective to reduce the breeding," said Dr Nasim-Us-seraj, official of entomology department of the DCC.

DCC has taken larvaecide as their main strategy to control mosquito and it has employed four spray-men for each of the 90 wards. The spray-men are supposed to spray in their particular areas for four times a day.

But city dwellers allege that the spray-men do not perform their duty regularly. "If the areas were sprayed regularly, mosquito could not have increased to much," alleged Habibullah, a resident of Elephant road.

Meanwhile, drains, ponds, and canals in the city that covers over 2,000 acres of low-laying area have become ideal breeding grounds for mosquitoes.

It is alleged that DCC has failed to keep clean the city waterbodies including derelict ponds, polluted canals, and stagnant drains.

"We are hopeful to control the situation as we are planing to take special drive to control mosquito breeding as well to launch cleanliness drive," Dr Nasim said.