Phenotypic variability in the wing dimorphic species Triatoma guasayana in traits related to flight dispersion

GIGENA GV; RODRIGUEZ CS; FIAD FG; HERNÁNDEZ, ML; CARBAJAL DE LA FUENTE AL; PICCINALI RV; SANCHEZ-CASACCIA P; ROJAS DE ARIAS, A.; LOBBIA PA; ABRAHAN, L; BUSTAMANTE GOMEZ M ; ESPIMOZA, J; CANO, F; NATTERO, J

Congreso; II Congress of the Latin American Society for Vector Ecology; 2022

Triatoma guasayana is considered an emerging Chagas disease vector in the SouthernCone of South America. The presence of a population with brachypterous individuals, inwhich both wings are reduced, has recently been reported for this species. We aimed tounderstand if flight-related traits varied across populations, if these traits could explain thelack of flight dispersal in the brachypterous population, and if flight-related traits areassociated with geographic and/or climatic variation. The study involved 66 males from 10populations. We used digital images of wing, head and pronotum to estimate linear andgeometric morphometric variables. We analysed variation in size and shape using one-wayANOVA and canonical variate analysis (CVA), respectively. We used Mantel tests to studythe relationship between morphometric and geographic distances and the associationbetween size measurements using Pearson’s correlation. We explored covariation betweensize and shape variables using partial least square analyses (PLS). We tested theassociation of geographic and climatic variables with size measurements using linearregression analyses. We performed PLS analyses for shape measurements. Wing sizediffered significantly across populations. The CVA showed that wing shape of thebrachypterous population is well discriminated from wing shape of the other populations.There was a positive and significant association between wing shape and geographicdistances. The brachypterous population exhibited significantly larger heads than the otherpopulations. As for wing shape, the head shape of the brachypterous population was welldiscriminated from the rest of the populations. Pronotum width did not show significantdifferences across populations. Geographic and climatic factors were associated with sizeand shape of both wing and head, but not with pronotum width. Most traits related to flightdispersal varied across populations. Wing and head shape were the best markers of thecondition of lack of flight dispersal of the brachypterous population. Head measurements alsovaried in accordance with this condition. Geographic and climatic variables were associatedwith most of the flight-related traits.