A team of Researchers from Wildlife Conservation Division and Ugyen Wangchuck Institute for Environment and Conservation together with with the Butterfly Society of Japan (BSJ) and NHK Japan sighted some mating pairs of B. ludlowi at Bumdelling Wildlife Sanctuary.
The sighting also revealed considerable biological information about B. ludlowi Its hostplant is Aristolochia griffithi, which is also utilised as a hostplant by other Bhutanitis taxa. Bhutanitis ludlowi eggs are smaller than in other Bhutanitis and are laid on top of each other in a stacked pile arrangement. Video footage of live adults show that their flight is rapid with a deep wingbeat and frequent gliding. The forewings provide all propulsion, while the hindwings are unpowered during normal flight and trail behind the butterfly. Unlike many swallowtail butterflies, B. ludlowi does not continuously flutter its wings while feeding. Viburnum cylindricum flowers were the most commonly used adult food source.
Bhutanitis ludlowi was known from five specimens collected in Bhutan during 1933-1934 by the botanists Frank Ludlow and George Sheriff. Four of these specimens were referred to in the type description, which contained little information on the species’ biology other than they were collected at an altitudinal range of 2000-2200 metres in forest.