The Taj Mahal hasn't been the pristine Colgate white of postcards for the last few decades, and now the marble has spots and green marks. These are courtesy an insect attack from nearby Yamuna river. According to archaeologists, the pests are Goeldichironomus, a species that grows near polluted water bodies. The increasingly dirty Yamuna river near the Taj has served as a breeding ground for the insects. However, Head of Entomology Department at St John's College, Doctor Girish Maheshvri, said in spite of attacking the monument, the insects are not likely to inflict harm on the marble of the Taj.

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"Acting on a request by the Archaeological Society of India (ASI), we have identified the insect as Goeldichironomus. These grow in numbers when pollution levels of water bodies rise. They form a swamp and are attracted towards sand (stone). The swarming is a result of nuptial flight among the insects. They are attracted towards the Taj. The greenery on the monument's white marble is partially digested chlorophyll combined with their fecal matter. I don't think this will cause damage to the stone," Maheshvri said,

This is surprisingly not the first time these insects have attacked the Taj.

Cleaning the Taj

According to archaeologist Bhuvan Vikram Singh, cleaning the monument isn't as simple as rinsing it clean with water - there needs to be a cleaner ecosystem around the Taj.

"The deposit on the Taj is water soluble. We are trying to clean it with water. But cleaning the Taj Mahal with water will not solve the problem. We know where and how these insects grow, so if we solve the problem at the basic level, we can stop them from growing in numbers and there will be no marks on the Taj," he said.

Increasing urbanisation and industrialisation in Agra have taken pollution levels in the city to two or three times above global standards. Pollution levels in the Yamuna too have been increasing rapidly, with industrial waste being dumped into it on a regular basis.

Ash from dead bodies burnt in a nearby cremation ground that is released into the river is another factor.

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