Prey Selection by Pitcher Plant, Nepenthes khasiana in Meghalaya, India

Abstract

Nepenthes khasiana, an endangered pitcher plant endemic to Meghalaya and southern Assam, India seems to develop a pitcher for trapping small animals as their prey to supplement the nutrient deficiency which occurs in the soil. A study on the enigmatic meat-eating choice of N. khasiana is scarce. Hence, this study was conducted to find out their prey species covering all three hills of Meghalaya, India. A total of 90 pitcher samples (30 from each hill) were collected randomly and preserved in 70% alcohol which was further identified at the lower taxa level. A total of 71 species were identified up to the species level while another five were identified up to their genus level. Among this, 90.8% of species were insects (69 species) while the remaining 9.2% (7 species) were non-insect species. All these seven non-insect species belonged to single order Arachnida. The majority of them (71.1%, 54 species) were capable of flying while the remaining 28.9% (22 species) were incompetent to fly. Those species which were incompetent to fly belonged to orders Araneae, Dermaptera, Diptera, Hemiptera, Lepidoptera, and Odonata. The prey constituted the highest 23 species belonging to the order Hymenoptera followed by 11 species under Coleoptera, 9 species under Diptera, 7 species under Araneae, 6 species each under Hemiptera and Blattodea, 5 species each under Orthoptera and Lepidoptera, 2 species under Odontata and 1 species each under Mantodea and Dermaptera. The orders Hymenoptera and Diptera together contributed 83.3% of the total feeding spectrum. This further indicates the sustainable management of biodiversity securing the abundance of animal prey species for the conservation of pitcher plants in this landscape.