Nectar sugar composition and flower visitors for the naturalized exotic Lantana camara (Verbenaceae) at Central Argentina

Abstract

The aim of this work is to describe and quantify the flower visitors of the invasive Lantana camara L. (Verbenaceae) at the Chaco forest, and to analyze possible relations between nectar sugar composition and the main pollinators for this species. Volumes of nectar and sugar concentration were measured in six different populations of the naturalized exotic L. camara in Central Argentina. Quantitative nectar sugar composition was determined and compared between populations. In general, nectar sugar concentration ranged between 25-28% and volume per flower was very low (<1μL). Nectar sugars are glucose, fructose and sucrose for all populations, but hexoses clearly predominate over sucrose. Different insects were registered visiting the inflorescences. The more frequent pollinators were many species of diurnal butterflies, honeybees and bumblebees. A diverse insect assemblage visiting flowers of L. camara guarantees a high fruit production which can be related to the invasion process of this species in the Chaco region from Central Argentina.