Lysathia sp. nov. and Lysathia flavipes: Molecular and morphological unraveling of biocontrol agents for Myriophyllum aquaticum and Ludwigia grandiflora subsp. hexapetala

FALTLHAUSER, ANA C.; CABRERA, NORA; HERNÁNDEZ, M. CRISTINA; SÁNCHEZ RESTREPO, ANDRES; ROUAUX, JULIA; SOSA, ALEJANDRO J.

Puerto Iguazú

Simposio; XVI International Symposium on Biological Control of Weeds; 2023

FuEDEI y CERZOS-CONICET

Water primrose (Ludwigia grandiflora ssp. hexapetala; Onagraceae) and parrot’s feather(Myriophyllum aquaticum; Haloragaceae) are aquatic plants native from South Americaand coexist in their natural environment growing in shallow waters of the centre and northof Argentina. Both species are aggressive weeds that have invaded several countries. Theflea beetle Lysathia flavipes (Coleoptera, Chrysomelidae) was found in the 80’s causingheavy damage to water primrose and moderate damage to parrot’s feather. In the 90’sspecimens of Lysathia sp. were imported from Rio de Janeiro province, Brazil, to SouthAfrica where it was studied and released as a biocontrol agent for parrot’s feather. Thesespecimens were identified as an undescribed species and the lack of specialists on thiscomplex Neotropical genus has hindered its description to date. On the other hand,extensive surveys on Ludwigia spp. in Argentina revealed frequent and abundant damageproduced by L. flavipes. However, preliminary morphological studies showed variations inbody coloration and female genitalia suggesting the presence of more than one species. Toclarify this complex taxonomic situation with both species and to confirm if L. flavipesutilises both hosts, morphological and molecular studies were carried out. DNA wasextracted from 48 individuals of L. flavipes (Argentina and Uruguay), L. sp. (South Africa)and L. ludoviciana (United States of America). The COI (~772-bp) region was amplifiedand sequenced in both directions from each sample with primers C1J2195 and TL2N3014.A phylogenetic tree (maximum likelihood and Bayesian methods) and haplotype networkwere obtained. Results showed that the Lysathia. sp. utilised in South Africa, clearlyseparates from the samples collected in Argentina, except for two specimens of the northeast of Argentina, representing perhaps the southernmost distribution of the Lysathia sp.The remaining specimens, L. flavipes sensu lato, showed variability but not related to thehost plants. There are three specimens collected as L. flavipes that are probablydifferent/new species. Lysathia flavipes s. lat., also separates from specimens of L.ludoviciana except for three samples that were more similar to the latter than to L. flavipes.To conclude, after morphological and molecular research, the Lysathia sp. utilised asbiocontrol agent against M. aquaticum is a species nova that will soon be published with afull description and will be named after Dr. Carina Cilliers, from South Africa. After DNAresults, specimens of L. flavipes s. lat. are also being described morphologically to redescribe the species.