Contribution of wet zone coconut plantations and non-agricultural lands to the conservation of ant communities (Hymenoptera: Formicidae) in Sri Lanka

Abstract

Agricultural practices are blamed for the reduction of ant diversity on earth. Contribution of four coconut plantations (CP) and four non-agricultural lands (NL) for sustaining diversity and relative abundance of ground-dwelling and ground-foraging ants was investigated by surveying them from May to October, 2018, in a CP and a NL in Minuwangoda, Mirigama, Katana and Veyangoda in Gampaha District that lies in the wet zone, Sri Lanka. Worker ants were surveyed by honey baiting and soil sifting along two transects at three, 50 m2 plots in each type of land. Workers were identified using standard methods and frequency of each ant species observed by each method was recorded. Percentage frequency of occurrence observed by each method, mean percentage frequency of occurrence of each ant species and proportional abundance of each species in each ant community were calculated. Species richness recorded by both methods at each CP was 14–19 whereas that recorded at each NL was 17–23. Shannon-Wiener Diversity Index values (Hʹ, CP: 2.06–2.36; NL: 2.11–2.56) and ShannonWiener Equitability Index values (Jʹ, CP: 0.73–0.87; NL: 0.7–0.88) showed a considerable diversity and evenness of ant communities at both types of lands. Four coconut plantations had 29 species in 23 genera of 5 subfamilies, Dolichoderinae, Dorylinae, Formicinae, Myrmicinae and Ponerinae. Four NLs consisted of 36 species in 26 genera of 7 subfamilies including additional Leptanillinae and Pseudomyrmecinae. Several species were restricted to coconut or non-agricultural lands while many species were common to both types of land

Keywords

• impact of agricultural practices
• non-agricultural lands
• coconut plantation
• ant diversity