NEOTROPICAL TREE SPECIES AND THEIR FAUNAS OF XYLOPHAGOUS LONGICORNS (COLEOPTERA, CERAMBYCIDAE) IN FRENCH-GUIANA

Estimates of the total number of species in existence are based, in pa rt, upon assumptions about the host specificity of tropical insects. T hese estimates are difficult to evaluate because there is so little da ta available describing the host-plant affiliations of tropical insect s. Over a three-year period, 690 trees in the Sinnamary River Basin of French Guiana were felled and investigated for their associated ceram bycid fauna. These trees (belonging to approximately 200 species repre senting 38 plant families) ultimately gave rise to 334 species of cera mbycids, One-quarter of these beetle species had not yet been describe d, and hundreds of previously unknown host-plant associations were doc umented. These data are presented in a table which also includes the r esults of additional rearing experiments in French Guiana, as well as selected literature references. Organized by host-tree family the tabl e facilitates the circumscription of beetle guilds occurring on relate d 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 rat ios of specialist:generalist species, The majority of the specialists successfully reproduced in related tree species belonging to a particu lar plant family; only a few cerambycid species appear to depend exclu sively on a single host, These data contribute to an understanding of host specificity and host fidelity in tropical insects.