On the anomalous altitudinal distribution of west Himalayan troidini and papilionini (Papilionidae)

Abstract

The altitudinal distribution of those Papilioninae species that occur in both eastern and western parts of the Himalayan range is compared. Ten species were found to ascend with the latitude, one descends as latitude increases and fourteen are almost unaffected by latitude. The presence of a suitable larval host plant appears to be one of the decisive factors governing altitudinal distribution of these species. In four Papilioninae species, the same subspecies has exclusively colonized entirely different habitats in different parts of the Himalaya.