Antennal phenotype and olfactory responses of mexican haplogroups of the Triatoma dimidiata complex, vectors of chagas disease

MAY COCHA IRVING; ROJAS JULIO; RAMSEY JANINE; GUERENSTEIN PABLO

Cuernavaca, Morelos, Mexico

Congreso; II Congreso Internacional de Vectores (Hemiptera; Reduviidae: Triatominae) y del Trypanosoma cruzi Simposio Internacional sobre la enfermedad de Chagas; 2016

Universidad Autonoma de Morelos, Facultad de Medicina, Facultad de Ciencias Biologicas, Colegio de Biologos del estado de Morelos A.C.

Triatoma dimidiata (Latreille) is a species complex that spans North, Central, and South America and which is a key vector of all known discrete typing units (DTU) of Trypanosoma cruzi, the etiologic agent of Chagas disease. Although morphological and genetic studies indicate that T. dimidiata is a species complex with three principal haplogroups (hg) in Mexico, different markers and traits are still inconclusive regarding the number of differentiated populations of this complex and their taxonomic level. In order to clarify the systematic status and infer evolutionary relationships among these vectors of Chagas disease, we analyzed whether the antennal phenotype and/or olfactory electrophysiological responses may have taxonomic value within the complex, and if there is an association between relative abundance of chemosensory sensilla and/or olfactory responses, and the phylogeny of the species group in Mexico. The abundance of each type of chemosensory sensilla (basiconic and thick and thin- walled trichoids) on the antennae, and the electrophysiological responses of chemosensory sensilla were studied in the three haplogroups and compared using Kruskal Wallis non-parametric and multivariate discriminant analyses. The three types of chemosensilla were present on the pedicel and both flagellar segments of adult insects. There were significant differences in the number of these antennal sensilla between females and males. Discriminant analyses indicate significant differences in the antennal phenotype and the electrophysiological responses between haplogroups.