Over the past few days, videos of massive clusters of microscopic, mosquito-like insects that seem to form a “tornado” in some parts of Pune have raised a lot of alarm. According to experts, the phenomena itself is not rare, and the insects in question are not mosquitoes but rather members of the Chironomidae family of insects.
Retired zoology professor Dr. Hemant Ghate told the media, “This is not an unusual phenomenon,” and that the main source of the issue is untreated sewage, which is not being handled. Since their blood contains haemoglobin, their larvae appear reddish, similar to mosquito larvae. These insects are widespread in the Mula-Mutha River and are particularly common in organic matter-polluted waters.
According to Dr. Ghate, these insects’ pupae (the stage between larva and adult) develop into adults at suitable warm temperatures, which is why a high number of adults that resemble mosquitoes emerge as swarms. “A big number of adults soar over the lake, their swarms appearing like waves as they sway in a light wind. These don’t bite, but their prevalence points to rivers contaminated by sewage, the man said.
The retired professor said, “Their larvae feed on organic matter, but the adults have a short lifespan and perish soon after laying eggs in water.”
It is also possible to observe the abundance of larvae in the water near Sambhaji Bridge. The larvae consume organic waste from sewage systems. It is carried away by the monsoon. He pointed out that untreated sewage also produces phosphate and nitrogen, which encourage the growth of hyacinth. “On a still day with no wind, the swarms appear as a plume of smoke coming from trees or buildings near the river,” he added.
