The highest diversity of galling insects: Serra do Cipo,

Abstract

During the past decade many studies have been carried out on the distribution of gall- forming insects along gradients of temperature, humidity, elevation, and latitude. Over 300 localities have already been sampled around the world representing numerous vegetation types such as shrubland, desert, chaparral, cerrado, savanna, tropical rain forest, taiga, tundra, and pine forest using sound and field-tested methods. The peak of species richness has been found at low and dry elevations, in areas of sclerophyllous vegetation. Nevertheless, gallers are most species rich and abundant in dl' kbitats. Among alI habitats studied, the Brazilian cerrado has the richest fauna of galling insects. At 900 m altitude in a cerrado area at the base of the Serra do Cipo in south-east Brazil, we found the richest galling insect fauna (forty- six species in a census of forty-five trees, 100 shrubs and 1000 herbs per site). At this elevation, the soil is rocky and sandy, nutrient-poor, and the vegetation is dominated by woody, sclerophyllous plants, with few herbs. The plant most attacked was Baccharis concinna (Asteraceae) which supported fifteen galling species.