Two new localities of Sri Lankan Relict Ant Aneuretus simoni Emery, 1893 (Formicidae: Aneuretinae) with the very first record in the intermediate zone

Abstract

Aneuretus simoni, an ant species endemic to Sri Lanka, is the only extant species of the subfamily Aneuretinae and is classified as critically endangered. Currently this species is known from the island few wet zone forests only. During a litter ant study in Knuckles mountain range, this rare ant was discovered from two new localities; Moraella rain forest (wet zone), and semi evergreen forests at Rambukoluwa (intermediate zone), extending the range of A. simoni within the wet zone and to the intermediate zone of Sri Lanka for the first time. Litter ant fauna of the two forests was sampled by laying three 100 m transects at each forest. On both sides along each transect, 1x1 m quadrates were installed at every 20 m interval and the ants were collected using Winkler extraction and hand picking. A total of 155 A. simoni workers were collected from Moraella rain forest (relative abundance 1%) and from semi evergreen forest (relative abundance 2.6%), with 92% of the workers being collected from Winkler extraction solely. Rainfall 2000 mm seems to be an important factor determining the distribution of A. simoni. Random collection of ants in semi evergreen forests showed that A. simoni inhabits forest edges as well, implying that this species does not require deep rain forest condition for survival. Therefore, further studies should be conducted to record the distribution of A. simoni within the country to re-eval