Nepenthes infauna

Infaunal mosquito larvae in the pitcher fluid of Nepenthes rajah
Accumulation of prey, such as in this Nepenthes rafflesiana pitcher, may attract nepenthexenes.
Recently drowned insects, such as this large beetle caught by Nepenthes ovata, constitute basal species in the pitcher food web and are consumed by the infauna.
Moth caught by an upper pitcher of Nepenthes neoguineensis
No infaunal organisms have been recorded from the pitchers of Nepenthes aristolochioides. It is thought that the structure of the traps may serve to disorientate emerging adults and so infaunal species may avoid colonising them.
In 1991, a study was carried out on the pitcher infauna of Nepenthes ampullaria, a species that is partially detritivorous.

Nepenthes infauna are the organisms that inhabit the pitchers of Nepenthes plants. These include fly and midge larvae, spiders, mites, ants, and even a species of crab, Geosesarma malayanum. The most common and conspicuous predators found in pitchers are mosquito larvae, which consume large numbers of other larvae during their development. Many of these animals are so specialised that they cannot survive anywhere else, and are referred to as nepenthebionts.[1]

The complex relationships between these various organisms are not yet fully understood. The question of whether infaunal animals "steal" food from their hosts, or whether they are involved in a mutually beneficial (symbiotic) association has yet to be investigated experimentally and is the source of considerable debate. Charles Clarke suggests that mutualism is a "likely situation", whereby "the infauna receives domicile, protection and food from the plant, while in return, the infauna helps to break down the prey, increase the rate of digestion and keep bacterial numbers low".[2]

  1. ^ Beaver, R.A. 1979. Fauna and food webs of pitcher plants in West Malaysia. Malayan Nature Journal 33: 1-10.
  2. ^ Clarke, C.M. 1997. Nepenthes of Borneo. Natural History Publications (Borneo), Kota Kinabalu, p. 39.