Portal de Periódicos da CAPES

Neotropical Heliconia Insect Communities

1982; University of Chicago Press; Volume: 57; Issue: 1 Linguagem: Inglês

10.1086/412573

1539-7718

Richard P. Seifert,

Plant and Fungal Species Descriptions

The insect fauna associated with Heliconia plants is one of the most extensively studied of all (non-cultivated) Neotropical insect-plant associations. Studies on Heliconia insect communities have centered on either the herbivorous insects that feed on young rolled leaves, or on those insects that live inside the water-filled floral bracts. I hypothesize that Heliconia floral morphology, in which flowers are protected in water-filled, cuplike bracts, evolved as a defense against flower-feeding and seed-eating insects. This small body of water has, however, attracted a varety of aquatic insects which are Heliconia-specific. Much of the research on Heliconia insect communities sheds light on more general hypotheses concerning the ecology and evolution of tropical insect communities. Heliconia research has pointed out the importance of plant biochemistry, plant phenology, and local plant distributions in determining the life history patterns, species diversity, and population densities of obligate insect associates. Studies on the leaf-feeding herbivores and the bract inhabitants indicate that neither intraspecific nor interspecific competition is a major structuring element in these communities. Parasitism, facilitation, and habitat age are more important than competition in structuring these insect communities. A clear succession can be followed among the insects in the Heliconia bracts. Insect species that are better adapted to water low in detritus are found in the youngest bracts, whereas insect species that use, or are tolerant of, high levels of detritus are found as the bracts age. Finally, biogeographyc patterns show that local accumulations of insect species in Heliconia inflorescences follow a power function similar to that which is used to describe the accumulation of species on islands. On a larger scale, moisture and number of Heliconia species in any location seem to be important in determining species richness among leaf-feeding insects, whereas floral morphology, bract size, and geographic location are important in determining the species composition of the insect communities in Heliconia inflorescences.