New findings of the Caenis ulmeriana-group (Ephemeroptera: Caenidae) in the Western Ghats, India

Caenis ulmeriana Malzacher, 2015 is recorded for the first time from the Western Ghats, India. Prior records of this species encompass Java, Sumatra, Thailand, Myanmar, and the Philippines. Notably, the Indian population of C. ulmeriana showcases variability, including slight changes in the shape of forceps in the male subimago and increased denticulation in the midclaw, a reduced number of setae in the Y-ridge of tergalius II, and differing shape of sternum IX in the larvae compared to other continental and island populations. The species number of Caenis Stephens, 1835 has now increased to twelve in India. A distributional map detailing the range of C. ulmeriana in the Oriental region is also provided herein.