 |
 |
LANKALIBRARY FORUMLankaLibrary Forum is a meeting place for those who are interested in Sri Lanka and her people |
|
|
Page 1 of 1
|
[ 1 post ] |
|
Author |
Message |
Saman
|
Post subject: LIFE HISTORY OF THE TAMIL YEOMAN BUTTERFLY Posted: Sun Mar 28, 2010 11:21 am |
|
Joined: Fri Aug 12, 2005 12:54 pm Posts: 192
|
Life history of the Tamil Yeoman ButterflyBy Dr. Nayana Wijetilaka Department of Zoology, Faculty of Science, University of Peradeniya, Sri Lanka@ TIGERPAPER: Vol. 36: No. 2 April-June 2009The Tamil yeoman butterfly (Cirrochroa thais), first described by Fabricius in 1787, belongs to the family Nymphalidae which comprises 67 species in Sri Lanka, including seven endemics (Perera and Bambaradeniya, 2006.) This is the only member of the genus Cirrochroa recorded in Sri Lanka, and the species is restricted to Sri Lanka and India. It is not an uncommon butterfly, and occurs throughout the island up to 1,200 meters above sea level. The Tamil yeoman is a strong butterfly and can fly at considerably great speeds when threatened and disturbed; however, the species can be easily approached while feeding. This species usually flies up to tree canopy level and can also be seen on wet patches on the ground, depicting a large microhabitat selection. Tamil yeoman butterflies breed throughout the year and the known host plants of the caterpillars belong to the family Flacourtiaceae, especially Hydnocarpus wightiana (Davidson & Aitken, 1890).

In August 2007, a Tamil yeoman butterfly was observed ovipositing on the underside of a leaf of a Makulu (Hydnocarpus venenata) tree near a river bank at Doluwa in Kandy district. This is an endemic plant and grows along water courses in the wet zone of Sri Lanka. The oviposition site was the underside of a young leaf, 1.8 m above ground, and shady. The egg clutch of the species was unusual in form as the ten eggs were attached to each other in the shape of a short beaded string. The Tamil yeoman is the only known butterfly that shows this type of egg-laying pattern in the country (M. van der Poorten, pers. comm.). The eggs were originally yellowish green in color, 1.5x1.5 mm in size and cylindrical in shape and showed clear longitudinal ridges, continuing along the egg string.

The egg clutch was removed with the branch from its original location and kept in a glass container under optimum conditions. The eggs hatched four days after laying, but only three hatchlings emerged. The rest of the eggs may have been unfertilized. The caterpillars were fed on fresh shoots, young leaves and young stems of the plant. Feeding was initiated from the leaf tip and continued towards the leaf base in an irregular manner. Feeding was observed randomly during the day time. The larvae had six rows of uniformly black, branched, shiny spines, two sets dorsally and two sets each on the lateral sides. Two black characteristic spots were present on the yellow forehead and one on each lateral side of the head. Along the two sides of the body was a brown stripe edged below by a white line.
By the 8th day after hatching the larvae were 26 mm in length. They stopped feeding by the 10th day and were observed actively moving on the plant, probably searching for a suitable place to pupate. By the 11th day all three caterpillars were observed hanging on small silken pads on the underside of leaves.

By 12.20 hrs of the same day, one caterpillar had metamorphosed into a bright yellow chrysalis, and the others did the same a few minutes later. Curved spine-like projections depicted the locations where the branched spines were present on the body of the caterpillar.

Eventually the chrysalises changed colour to dark brown by the 18th day after hatching.
One week after pupation, three brilliantly colored imagoes emerged on the same day at 15.10 hrs, 15.24 hrs and 15.36 hrs respectively. They remained on the same leaves for nearly one and a half hour until they experienced their first flights. References - D’ Abrera, B. 1998. The Butterflies of Ceylon. Wildlife Heritage Trust, Sri Lanka
- Kolambaarachchi, R. 2000. Notes on the life cycle of common Mormon (Papilio polytes Linn, 1758). Sri Lanka Naturalist.
- Nanayakkara, S. 2000. Breeding the Common Grass Yellow Butterfly. Loris 22(2):52-53
-Perera, W.P.N. and C.N.B. Bambaradeniya. 2006. Species Richness, Distribution and Conservation Status of Butterflies in Sri Lanka. The fauna of Sri Lanka, IUCN-The World Conservation Union.
- Woodhouse, L.G.O. 1950. The Butterfly Fauna of Ceylon. Ceylon Government Press.Author’s address: Department of Zoology, Faculty of Science, University of Peradeniya, Sri Lanka; nayanata at gmail.com
|
|
 |
|
 |
|
|
Page 1 of 1
|
[ 1 post ] |
|
Users browsing this forum: No registered users and 1 guest |
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum
|
|
 |