Dengue mosquito’s enemy missing in action


The disappearance of around 90 percent of frogs, reckoned to be natural enemies of mosquitoes, is a vital cause behind the dengue outbreak,” revealed World Wildlife Fund (WWF) Pakistan. WWF Pakistan disclosed that frogs acted as predator against all species of mosquitoes including dengue and kept the number of mosquitoes in balance according to the ecosystem. As frogs were on a catastrophic decline, dengue-like mosquitoes were on the loose.
WWF Pakistan Senior Director Dr Ghulam Akbra told Pakistan Today that frogs were a part of the ecosystem and were abundant in ponds, which the city possessed. “Frogs have died as a result of local human activity, while the epidemic has also reached remote areas. Major causes of frog decline are habitat destruction, chemical pollution, climate change, epidemics and human activity,” he said.
Like dengue mosquitoes, frogs too lived in clean water and ate mosquito eggs and larva, checking outburst of dengue mosquitoes. However, he said that since the water table was getting polluted due to massive spay of pesticides on crops, release of toxic water by industries into land and sewerage of houses, natural habitats of frog had been so poisoned that frogs were near to extinction.
He said that flying-dragons, bats and fish were also natural killer of mosquitoes and a national policy was needed to protect such harmless mosquito-killers as a biological solution to eradicate dengue and other species of mosquitoes.
Shahid Mehmood, 70, resident of Shadman, said he used to see frogs, often in monsoon, jumping in and out of the ponds. “We used to hear them croaking in silence during the night, but it has been long since we saw a frog. It appears that they are no more in our world,” he said.
Muneez Fatima, an elderly woman at Township, said, “I did not see any frog this monsoon. They had been eating mosquitoes for million of years. Where did they disappear? Dengue mosquitoes are on a killing spree because frogs are not around,” she opined.
Punjab Environment Protection Department Deputy Director (EIA) Naseemur Rehman Shah said that frogs like species swallowed not only the eggs but also adult mosquitoes. “As long as they were present, dengue-like mosquito never threatened human life,” he added. He revealed that government in consultation with experts had started planning to protect the anti-mosquito species as a long term strategy.
During the seminar conduced by EPA at Punjabi Complex, speakers focused on the issue, he said and hoped that soon government would chalk out integrated strategy to end the epidemic.
CDGL Environment Department official said that frog was currently nationally threatened, and many of its species might have disappeared altogether.
“Over the past 50 years, scientists have recorded major declines in frog populations around the world. A few species have vanished completely,” he said.
Frogs and all amphibians are sensitive indicators of water quality because they absorb gases and chemicals directly through the skin. Vanishing frogs could be an early warning of serious water problems in the environment. He said that the issue was important enough that a worldwide group of scientists, the Declining Amphibian Populations Task Force (DAPTF), had been formed to collect data about the frog decline.