![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
Abstract
The semi‐aquatic grasshopper Cornops aquaticum (Bruner, 1906) is native to South America, with a distribution from the Argentinian pampas to the Gulf of Mexico, and is currently being proposed as a biological control agent for the invasive water hyacinth (Eichhornia crassipes) in South Africa. This study reports results of a neutral molecular marker (microsatellites) study on C. aquaticum within its native range. The data were analysed for levels of diversity and structure within/between South American populations, and correlations between host plant, geography and environmental/climatic variables were investigated. We found no evidence to support associations between host plant use and microsatellite genotypes (hypothesis 1). High levels of gene flow and weak genetic clustering of populations indicate a lack of differentiation, therefore an interaction between climate and local genotype (hypothesis 2) seems unlikely. Our results suggest that C. aquaticum may not have “tightly” coevolved with its host Eichhornia spp. (Pontederiaceae) as originally thought, and that instar variation might be due to the effect of local climate on phenotype (hypothesis 3) or possibly a locally adaptive trait.
Acknowledgments
E.G.B. and J.A. dedicate this paper to Wolfgang J. Junk, MPI Plön, on the occasion of his 65th anniversary. This contribution forms part of the international project in Host–Insect Co‐evolution on Water Hyacinth (HICWA) at the Tropical Ecology Working Group (Max‐Planck‐Institute for Limnology, Plön, Germany), coordinated by J. Adis. Initial thanks go to A. L. Nunes (Museu Paraense Emílio Goeldi, Belém, Brazil), S. Capello, E. Drago and M. Marchese (INALI, Santo Tomé, Argentina), A. Poi de Neiff and M. C. Franceschini (CECOAL‐CONICET, Corrientes, Argentina), M. G. Lhano (La Plata, Argentina), to the late H. Oberholzer (ACU, Pretoria, South Africa), and Perry Polar and Moses Kairo (CABI, Trinidad) for collection of samples. Thanks also to Heitor Bastos (UFPA, Belém, Brazil) for help received in the Brazilian laboratory. Finally, many thanks to E. Bustorf (MPIL, Plön, Germany) for lab support. E.G.B. was supported by a Max‐Planck‐Society post‐doctoral scholarship.