What distribution models of alligator weed in its native and invaded ranges tell us about its invasion story and biological control

SÁNCHEZ?RESTREPO, ANDRÉS F.; RECHE, VANINA A.; CABRERA, NORA; PAN, XIAOYUN; PRATT, PAUL; SOSA, ALEJANDRO J.

ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA

WILEY-BLACKWELL PUBLISHING, INC

Año: 2023 vol. 171 p. 1009 - 1018

0013-8703

Ecological niche models of species occurrence have gained interest in biological controlprograms to improve efficiency, reduce risks, and to inform when and how controlagents may be released and/or surveyed. Alligator weed, Alternanthera philoxeroides(Mart.) Griseb. (Amaranthaceae), is an amphibious aquatic plant native to southernSouth America that has invaded several countries around the world. In this study, ouraim was to quantify the current and to model the future alligator weed geographicaldistributions in its native range in South America, and in its introduced range (USA, thecountry where biological control of the weed was first implemented). Additionally, wemodelled the current and potential distribution of its biocontrol agent Agasicles hygrophilaSelman & Vogt (Coleoptera: Chrysomelidae), released in the USA in 1964, andother potential biocontrol agents, including the flea beetles Disonycha argentinensisJacoby and Systena sp. In total, 19438 occurrence records of alligator weed, 253 of A.hygrophila, 48 of D. argentinesis, and 19 of Systena sp. were compiled. Niche modelspredicted expanded distributions of alligator weed, particularly in northern regions ofSouth America. However, the models of the flea beetles A. hygrophila, D. argentinensis,and Systena sp. did not predict geographic range expansion and the future scenariosare similar to current distributions. Our study predicts an increase in the suitable areasfor alligator weed in South America in future scenarios of global warming, whereasthese new areas would not be as favourable for the biocontrol agents historically used.