SOME SELECTED RESEARCH WORK ON LEPIDOPTERA
Variations of Phenotypic plasticity of Mycalesis janardana (Lepidoptera: Satyrinae) along an elevation gradient on Mt Rinjani, Lombok, Indonesia
Many insect species show variations in phenotypic plasticity to cope with the varying environmental conditions. Such ability of changing phenotype according to the environmental cues can be adaptive and advantage if that increases fitness to environmental pressure applied (Stearns 1976).
One such major morphological variation is the butterfly wing morphology. Wing melanisation play a major role not only in protective resemblances (i.e. being camouflage with environment) by being crypsis (Woodhouse 1950, d’ Abrera 1998) but also in thermoregulation, since darker surfaces absorb more radiation. Markings, especially eyespots are also used for giving warning signals and for attracting sex partners.
Melanisation and eyespots variations of butterflies have been extensively studied (Rolend 2006, Wourms & Wasserman 1985). Among them melanisation and wing pattern changes of the species of sub-family Satyrinae is prominent. Most of the studies have been done with African species Bicyclus aynana belongs to sub familySatyrinae. Most of these studies have been conducted in simulated laboratory conditions.Studies on melanisation and eyespots variations of tropical Asian butterflies are scares. Present study was based on the specimens of Mycalesis janardana collected directly from the field in Lombok, a Southeast Asian tropical island. The genus Mycalesis distributed in warmer regions from central Asia to Australia and genus divers in South Asia and Wallacea.
Supervisor: Prof. Rhett D. Harrison
Relative abundance and spatial distribution of pest and non-pest Lepidoptera species (butterflies, skippers and moths) in rice agro-ecosystem
Paddy is a major cultivation in Sri Lanaka and rice is the major diet of majority Sri Lankans. Sri Lankans inherit invaluable knowledge of paddy farming descent from more than 3000 years. Many research institutes are also involve in rice researches. Resent study done at Bathalagoda (Bambaradeniya & Edirisinha, 2008) records 45 species of butterflies ( one rice pest), six skippers (two rice pest) and five moths (all are rice pest). There is another importance (other than pests) of this study; that is biodiversity; untill early 1980s conservationists did not realize the importance of the lands outside the portected area for bidiversity conservation.
Above study has limited to bund and field proper of paddy fields. Also this paddy cultivation was well managed one using systematic methodologies. But conventional paddy lands in addition comprise many sub habitats; streams or canals, associated hedge grows, small scrublands and abandoned fields.
Present study is being conducted in wet lowland paddy fields managed by traditional farmers. Findings of the study will be important for integrated pest management and biodiversity conservation.
Study of Hawk Moths (Lepidoptera: Sphingidae) and Silk Moths (Lepidoptera: Saturniidae) of Sri Lanka
Hawk moths or humming bird moths are very popular among armature entomologists as well as general nature explorers hence are well studied (i.e. distribution, life histories) throughout the world. Also Hawk moths are day flying or crepuscular (fly early morning or late afternoon)
Saturnids or Silk moths include worlds' largest and charismatic moths such as Hercules moth, Atlas moth and Luna moth. In Sri Lanka we have four species two atlas moths, Tussur moth which is used to produce yellow silk and Indian Luana moth or Moon moth. These Saturnids are popular in butterfly houses throughout the world as they are large, beautiful and breed in large number throughout the year.
So I selected these two families to popularize moths among Sri Lankans. Result is amazing and many calling on me to share their observations. If you see any moth or caterpillar as in above picture or in Sphingidea and Saturniidae please let us know. Presently I am studying biology and ecology of Sphingidae and Saturniidae of Sri Lanka.
Diversity of butterflies at different altitudes in the Knuckles region
Non nectar feeding behavior of Sri Lankan butterflies
Lepidoptera especially Papilionoidea (true butterflies) and Hesperoidea (Skipers) visit moist soil, mud, dung, urine, perspiration, saliva, ash, tree sap, aphid honeydew and carrion to drink water and dissolved nutrients, in a behavior known as puddling. Studies have shown that butterfly species have feeding preferences among pudling sources that these preferences differed among butterfly species. In puddling Sodium and sometimes protein are actively collected, which play a potentially important role in lepidopteran nutritional and mating ecology. This puddling behavior is more extensive in tropical areas. In a process of habitat conservation and restoration or rehabilitation for butterfly conservation, increasing the availability of nectar plants and host plants alone will not be sufficient.
Studies on Sri Lankan butterflies done before 1950s were mainly focused on their distribution, Life history and taxonomy relating to collection and rearing. Studies thereafter are few and limited to migration observations, notes on life history, checklists and comparative study of butterfly diversity in deferent habitats. Present study was design to observe different feeding habits of Sri Lankan butterflies.
Aluthwattha R.G.S.T. (2009), Non nectar feeding behavior of Sri Lankan butterflies: An essential study for habitat conservation and restoration, First National Symposium on Natural Resources Management (NRM 2009), Department of Natural Resources, Sabaragamuwa University of Sri Lanka (Abstract)
Impact of habitat deterioration due to alien invasive plants and agro- chemical use for butterfly composition
Loss of nectar and host plants due to invasion of Alien Invasive Plant Species (AIPS) and the effect of pesticides are two globally identified threats to butterflies, especially in tropical agricultural countries like Sri Lanka. Bundala National Park (BNP) located in the Hambantota District (6°08’ – 6°14’N, 81°08’ – 81°18’E), southeastern arid zone of Sri Lanka was identified as an ideal study area for understanding the effect of later two factors to butterfly faunal diversity since the park is under high threat of AIPS and it surrounds large agricultural schemes (Matsuno et al., 1998; Bambaradeniya, 2001).
[This study was done along with a large geochemical and ecological (wetland) study of Bundala National Park with the supervision of Dr. A. Dangolla, Dr. K. B. Ranawana and Dr. R. Chandrajith, University of Peradeniya]
Aluthwattha R.G.S.T., A. Dangolla, K.B. Ranawana, R. Chandrajith and G.A.U.P. Abeypala (2009), Impact of habitat deterioration due to alien invasive plants and agro- chemical use for butterfly composition: a case study in Bundala national park, Sri Lanka, Proceedings of the Peradeniya University Research Sessions 2009, University of Peradeniya (Abstract)
Survival rate in laboratory and field conditons and developing effective rearing methods for butterflies and moths