The impact of flower head endophages on seed set of a native population of Chromolaena odorata (L.) King & Robinson (Asteraceae)

Abstract

Chromolaena odorata (L.) King & Robinson, also known as siam weed, has negatively affected the ecology of several tropical and subtropical regions of the world and has caused them economic losses. The biocontrol of C. odorata is a challenge for many countries; however, several phytophagous insects are natural enemies of C. odorata. Here we present the main flower head feeding insects associated with a native population of C. odorata. The aims of this study were: (1) to evaluate both individual and aggregated impacts of endophagous insects on C. odorata seed production, and (2) to provide information on host specificity of each endophagous species at local and regional scales. The study was conducted in the cerrado area of the Reserva Biológica de Mogi-Guaçu, São Paulo, Brazil. We found 17 endophagous species from seven genera. We estimated that the endophages damaged at least 22% of all of the seeds C. odorata produced. Tephritid species were only found on the plant species from the tribe Eupatorieae, whereas lepidopteran and agromyzid species were found on the plant species from two or more Asteraceae tribes.