Associated insect guilds with the invasive Ludwigia peploides and L. grandiflora (Oligospermum section) in their native range

MARÍA CRISTINA HERNÁNDEZ; ANA C. FALTLHAUSER; GUILLERMO CABRERA WALSH

Simposio; 4th International Symposium on Weeds and Invasive Plants; 2014

The South American water primroses Ludwigia grandiflora (Michx.) Greuter & Burdet, Ludwigia grandiflora subsp. hexapetala (Hook. & Arn.) G.L. Nesom & Kartesz, Ludwigia peploides (Kunth) P.H. Raven, and Ludwigia peploides subsp. montevidensis (Spreng.) P.H. Raven (Onagraceae, Section Oligospermum), have become invasive in several watersheds of Europe, Asia and the U.S.A. Surveys were carried out in central and northern Argentina to find organisms that might serve as biological control agents. More than 20 insect species were found to feed on L. g. subsp. hexapetala, distributed in a variety of guilds, including 6 species with stem-borer larvae, 1 species with fruit-feeding larvae, 4 species with defoliating larvae, 2 species with defoliating larvae on young leaves and axil meristems, 1 species of cell content-feeder, and 3 species of sap-feeders. Nine of these species also have defoliating adults.The cell-content feeder Liothrips ludwigi (Thysanoptera), and a number of stemboring weevils are promising candidates as biocontrol agents for the countries where this plant is an aggressive invader.