Journal of Tropical Ecology

Table of Contents - 1999 - Volume 15, Issue 03  


Body size and host plant specialization: a relationship from a community of herbivorous insects on Ficus from Papua New Guinea

Vojtech  Novotny a1a3c1 and Yves  Basset a2a3
a1 Institute of Entomology, Czech Academy of Sciences and Biological Faculty, University of South Bohemia, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic
a2 Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Ancon, Panama
a3 Research Associates, Department of Natural Sciences, Bishop Museum, Honolulu, USA

Abstract

The relationships between body size and host specificity were studied in leaf-chewing and sap-sucking insect communities, including 792 species, feeding locally on 15 species of Ficus in a lowland rain forest in Papua New Guinea. A negative correlation between body size and host specificity, i.e., the tendency for large species to feed on numerous Ficus hosts and those smaller to have a more restricted host range, was found within both the sap-sucking and the leaf-chewing community. A more detailed analysis, which divided herbivorous species into three sap-sucking and four leaf-chewing guilds, revealed that the correlation between body size and host specificity was caused by differences in these traits between the guilds, while no such correlation was detected within any of the guilds. As the changes in feeding mode, defining various guilds, were unique evolutionary events, it is uncertain whether there is a functional relationship between feeding mode, body size and host specificity, or whether their correlation is only coincidental. It is suggested that, in the sap-sucking community at least, the positive body size versus host specificity correlation is a coincidental by-product of the causal relationship between the feeding mode and both the body size and host specificity. The causes of analogous patterns in a leaf-chewing community require further investigation. Methodological problems in the analysis of tropical insect communities, dominated by rare species, are discussed.

(Accepted December 20 1998)


Key Words: Auchenorrhyncha; Coleoptera; herbivorous guilds; leaf-chewers; Lepidoptera; Orthoptera; phloem-feeders; root-feeders; xylem-feeders; wood-borers.

Correspondence:
c1 Natural Sciences, Bishop Museum, 1525 Bernice Street, Honolulu, Hawaii 96817-0916, USA, E-mail: novotny@bishopmuseum.org