Neotropical tree species and their faunas of xylophagous longicorns (Coleoptera: Cerambycidae) in French Guiana

Abstract

Estimates of the total number of species in existence are based, in part, upon assumptions about the host specificity of tropical insects. These estimates are difficult to evaluate because there is so little data available describing the host-plant affiliations of tropical insects. Over a three-year period, 690 trees in the Sinnamary River Basin of French Guiana were felled and investigated for their associated cerambycid fauna. These trees (belonging to approximately 200 species representing 38 plant families) ultimately gave rise to 334 species of cerambycids. One-quarter of these beetle species had not yet been described, and hundreds of previously unknown host-plant associations were documented. These data are presented in a table which also includes the results of additional rearing experiments in French Guiana, as well as selected literature references. Organized by host-tree family, the table facilitates the circumscription of beetle guilds occurring on related hosts. Abundantly represented plant families typically gave rise to faunas including numerous taxonomically unrelated beetles. The beetle guilds associated with different plant families had very different ratios of specialist:generalist species. The majority of the specialists successfully reproduced in related tree species belonging to a particular plant family; only a few cerambycid species appear to depend exclusively on a single host. These data contribute to an understanding of host specificity and host fidelity in tropical insects.