Browsing by Author "Perera, K.A.M."
Now showing 1 - 5 of 5
- Results Per Page
- Sort Options
Item Ants as Biological Indicators of Human Disturbance – evidence from Sinharaja forest and tea and rubber fields in Ratnapura district(University of Kelaniya, 2006) Dias, R.K.S.; Perera, K.A.M.Ants are a major group of insects in the forests as well as in agricultural fields in Sri Lanka. If the presence or absence of some ant taxa in disturbed areas differs from that of a forest reserve was investigated by sampling worker ants from tea and rubber fields in Godakawela and the primary and secondary forest regions in Sinharaja forest in September and October, 2005, respectively. Heavy rains prevailed during the sampling on both occasions. Honey baiting (25), soil sifting (10), hand collection (10) and litter sifting (10) during day time and pitfall trapping (10) at night along a 100 m transect were carried out in the forest while all of those methods except litter sifting were carried out in the tea and rubber fields. Depth of litter, soil moisture content and temperature and air temperature were also recorded. Worker ants belonging to seven subfamilies, Aneuretinae, Amblyoponinae, Cerapachyinae or Leptanillinae, Dolichoderinae, Formicinae, Myrmicinae and Ponerinae were recorded from the primary and secondary forest regions whereas five subfamilies, Dolichoderinae, Formicinae, Myrmicinae, Ponerinae and Pseudomyrmicinae were observed in both tea and rubber fields. Worker ants of subfamily Amblyoponinae were recorded from rubber fields but they were not observed in the tea fields. Thirty two morphospecies of ants from the primary forest region and twenty seven morphospecies from the secondary forest region were observed during this study. Thirty and thirty four morphospecies of ants were recorded from tea and rubber fields, respectively. Although Species Richness values did not show significant difference (p>0.05) for the four types of ecosystems, it was evident that Anoplolepis gracilipes (Jerdon), Diacamma rugosum Mayr, Meranoplus bicolor (Smith F.), Odontomachus simillimus Smith F., Oecophylla smaragdina Fabricius and Tetraponera rufonigra (Smith F.) could be considered as biological indicators of disturbance as they were restricted to tea and rubber fields. Also, Aneuretus simoni Emery, Technomyrmex bicolor Emery, Anochetus sp. and Leptogenys spp. were restricted to the two types of forest regions but further research would be carried out to confirm these observations.Item Comparative study of the diversity and the community composition of the worker ants I a forest reserve and a secondary forest in Sri Lanka(Sri Lanka Association for the Advancement of Science, 2005) Dias, R.K.S.; Perera, K.A.M.Item Diversity of Worker Ant Communities (Order: Hymenoptera; Family: Formicidae) in Non-Agricultural Lands in Ratnapura District(University of Kelaniya, 2007) Dias, R.K.S.; Perera, K.A.M.An ant survey (Jan., 2004 · Dec., 2005) conducted in the forests and some selected agricultural lands in Ratnapura district for the preparation of an inventory and to locate the habitats of the endemic ant, Aneuretus simoni Emery, was extended to nonagricultural lands in the district, from January to June in 2006. Worker ants were sampled along three transects laid in such a land in Kuruwita (January), Dumbaramanana (February), Godakawela (March), Ambilipitiya (April), Balangoda (June) and Nivithigala (June). Along each 100 m transect, twenty five honey baits were kept at four metre intervals and collected after an hour into bottles filled with 85% ethanol. In addition, ants sampled by soil sifting (20) and hand collection (1 0) at 4 m intervals were also preserved in 85% ethanol. Ants were sorted, identified to the possible taxonomic levels and enumerated in the laboratory. Air (23°- 35° C) and soil temperatures (22° - 33 °C), soil moisture content (17% - J7%) and soil organic matter (2% - 9%) of each site were also recorded. Although members of six subfamilies, Amblyoponinae, Cerapachyinae, Dolichoderinae, Formicinae, Myrmicinae and Ponerinae and, fifty six species and morphospecies of ants were recorded, Aneuretus simoni (Subfamily: Aneuretinae) was never observed during this study. Significantly different Species Richness values (chi square test; p< 0.05) were recorded for the lands in Kuruwita (18), Dumbaramanana (19), Godakawela (28), Ambilipitiya (17), Balangoda (29) and Nivithigala (26). Technomyrmex albipes (36.8%) dominated the Kuruwita ant community while Pachycondyla sp. 2, Monomorium sp." 2 and Paratrechina longicornis were observed in considerable (>5%) proportions. Pheidole sp. 2 was dominant in Dumbaramanana whereas Tapinoma melanocephalum (24.8%), Technomyrmex bicolor (12.6%), Myrmicaria brunnea (10.4%) and Technomyrmex albipes (5.9%) were also observed in considerable proportions. Tapinoma melanocephalum was the dominant species recorded from Godakawela (28.9%) and Nivithigala (27%) study sites. In addition, Pheidole sp. 2 (10.9%) and Pheidole sp. 3 (10.9%) in Godakawela and Camponotus sp. 2 (11.4%) & Paratrechina longicornis (9.3%) in Nivithigala were observed in considerable proportions. The dominant ant species observed in Ambilipitiya and Balangoda were Anoplolepis gracilipes (72.9%) and Pheidole sp. 2 (36.9%), respectively. Considerable proportions of Tetramorium bicarinatum (9%) in Ambilipitiya and Pheidole sp. 4 (12.9%) in Balangoda were also observed. Anoplolepis gracilipes and Meranoplus bicolor were the species common to six disturbed regions and this observation indicated that these species may have a value as biological indicators of disturbance. The ponerines, Anochetus spp., Cryptopone spp., Diacamma ceylonense, D. indicum, Hypoponera spp., Leptogenys spp., Odontomachus simillimus, Pachycondyla spp. and Platythyrea sp., when present, were always observed in very low proportions. Although the reasons for the presence of different ant communities in the six lands were not investigated in detail it is apparent that each ant community observed in each land could be a reflection of the environmental quality of each land. Members of Subfamily Aenictinae, which were recorded from forests in Ratnapura were not observed in these lands.Item The first record of Aneuretus simony emery (Sri Lankan Relict ant) from Sinharaja forest and its relative abundance estimated by several sampling methods(Sri Lanka Association for the Advancement of Science, 2006) Perera, K.A.M.; Dias, R.K.S.; Yamane, S.