Happy New Year to all ButterflyCircle members and blog readers. It is the 1st of January of the year 2011, and we start off the year with some good news with the addition of one more species to the Singapore Checklist. The checklist is now at 296 species and counting, and we hope that the year 2011 will bring more good cheer.
A clump of the host plant of at least 4 different species of skippers - all on the same plant!
A shot of the inflorescence of the host plant and a close up of the florets
A female Formosan Swift (Borbo cinnara) ovipositing on the host plant that three other species of caterpillars were found, including that of the Detached Dart
Amongst the species that were successfully bred were the Palm Dart (Telicota augias augias), Full Stop Swift (Caltoris cormasa) and a Potanthus sp. which we could not identify with certainty. Horace later obtained a few more eggs to complete the life history of this Potanthus from the same clump of host plant.
However, the early stages of the caterpillar seemed to coincide with the pictures documented in the Butterflies of Hong Kong (Bascombe, Johnston & Bascombe) for the species Lesser Band Dart (Potanthus trachala). The distinctive head capsule and anal plate of the 5th instar caterpillar matches the same species on Plate 105 of the book, showing in full colour the early stages of this species.
Upon eclosion, the male and female specimens were examined and matched against the various references and ID keys. After consulting two experts - one from Hong Kong and one from Malaysia, it was confirmed that the species thus bred from the eggs and caterpillar found at this urban park was indeed Potanthus trachala tytleri.
For consistency of the common names given to the species in the South East Asian region covering Thailand, Malaysian and Singapore, we will give preference to the name Detached Dart, taking reference from the name given in the Butterflies of Thailand book by Pisuth Ek-Amnuay.
The Detached Dart is larger than the typical Potanthus species and usually larger than the more commonly encountered Lesser Dart (Potanthus omaha omaha). It has a wingspan of about 28-30mm, compared the the Lesser Dart's 20-24mm. and the Large Dart's (Potanthus serina) 30-35mm.
In the field, it is not easy to spot the differences amongst the lookalike Potanthus species, and it was only with this chance discovery of the early stages of this species that we now re-instate the Detached Dart to the Singapore Checklist. Given this find, there is always the possibility that more of the Potanthus species occur in Singapore as well. It will only be matter of time and luck that will yield more of these lookalike species to be added to the checklist in due course. Special thanks to Horace Tan for re-discovering this species through his recording of the early stages of the Detached Dart.
- [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
- Butterflies of Thailand, Pisuth Ek-Amnuay, 1st Edition, 2006
- The Butterflies of Hong Kong, M. Bascombe, G. Johnston, F. Bascombe, Princeton University Press 1999
- National Biodiversity Centre, National Parks Board, Singapore for issuing official research permits to selected members of ButterflyCircle to collect and document early stages of butterflies on State Land under NParks' jurisdiction