Parts of the Taj Mahal's pearly-white exterior are turning green, this time even in winter. According to the Archaeological Survey of India (ASI), the culprit is "Goeldichironomus", an insect species that deposits its droppings on the monument's marble surface.
First spotted in 2015, it leaves dark brown and green stains on the marble and the inlay work. It breeds in the polluted waters of the Yamuna river, an ASI official pointed out. "The ASI has been trying to get rid of the stains by washing them with distilled water and rubbing them with a cotton cloth. But the insect keeps reappearing during its breeding season (between March and April and September and October)