Structure and dynamics in Nepenthes madagascariensis pitcher plant micro-communities

The pitchers of Nepenthes madagascariensis are visited by a wide variety of insects attracted to the bright color of the pitcher, the nectar secreted around its opening and the odor of the fluid. The insect visitors appear to become disoriented over time and with increasing likelihood fall into the pitcher and drown. The pitchers form a temporary habitat functional for about three months. Several specialized arthropods including mosquito larvae (Uranotaenia bosseri, U. belkini), mites (Creutzeria sp.), and frit fly larvae (Chloropidae) complete their life cycle in the pitcher and depend directly or indirectly on the drowned insects falling into the pitcher. Colonization by these arthropods varies spatially and temporally between the two forms of pitchers (juvenile, rosette form and adult form). Mites (Creutzeria sp.) show a phoretic relationship in colonizing new pitchers by clinging to adult frit flies that emerge from the pitcher's fluid. Food web interactions in the Nepenthes madagascariensis pitcher are more complex than those reported by Beaver (1985).