On a migration of Catopsilia pomona (F.
This short note by the Rev. R. Cardon documents a mass migration of Catopsilia pomona (F.) observed in Upper Perak in May 1927, moving from north to south.
Cardon describes encountering the migration between Lenggong and Lawin, where thousands of the butterflies flew in dense swarms along the road, with some resting so thickly on wet ground that they were at risk of being run over by vehicles. He confirmed through netting that the migration was composed almost exclusively of C. pomona, with only a few C. pyranthe, C. chryseis, and C. scylla present as non-migratory associates (p. 314). He identified two female forms among his captures: a new form bidotata with two patches on the underside of the posticae, and the common catilla form with a large discal reddish patch (pp. 314–315). The migration lasted approximately four days, from 26 to 29 May, after which only isolated individuals remained (p. 315). Cardon also briefly compares this to a 1902 migration of Delias aglaia parthenope in Singapore and to Rev. L. C. Biggs’s 1881 account of D. aegialea migrations in Java (p. 315).