Triatoma mexicana ( Herrich-Schaeffer, 1848 )

Rengifo-Correa, Laura, Téllez-Rendón, Juan Luis, Esteban, Lyda, Huerta, Herón & Morrone, Juan J., 2021, The Triatoma phyllosoma species group (Hemiptera: Reduviidae: Triatominae), vectors of Chagas disease: Diagnoses and a key to the species, Zootaxa 5023 (3), pp. 335-365 : 349-350

Triatoma mexicana ( Herrich-Schaeffer, 1848)

( Fig. 5C, D, E )

Conorhinus mexicanus Herrich-Schaeffer, 1848: 71 . Meccus mexicanus ; Stål, 1859: 105. Triatoma mexicana ; Del Ponte, 1930: 886; Pinto, 1931: 71; Mazzotti, 1940: 2; Usinger, 1944: 52; Lent & Wygodzinsky, 1979:

270; Carcavallo et al., 2000: 28; Galvão et al., 2003: 11; Schofield & Galvão, 2009: 92; Salazar-Schettino et al., 2013: 68;

Monteiro et al., 2018: 284.

Diagnosis. Adult body length 25.0–26.0 mm. Postocular region slightly rounded. Pronotum black, with humeral angles acute. Discal tubercles present, elongate and conical. Lateral tubercles small, subconical. Clavus black on basal half, brownish on apical portion. Overall color of corium yellow to orange yellow, with black apex and central markings. Membrane of hemelytra dark brown. Fore femora 8.5–9.1 times as long as wide. Fore tibiae of male with very small spongy fossula. Male abdomen widened. Female abdomen strongly widened. Overall color of connexival segments yellow or orange yellow, with black markings on anterior third or half of each segment adjacent to intersegmental suture.

Specimens examined. Mexico. 1 male ( CAIM), Hidalgo, Jacala , Sto. Domingo, 18 vii 1999 , n/d. 1 male ( CAIM), Hidalgo, Metztitlan , Chimalacatla, 20 iv 2010 , V. Ángeles. 3 males ( CAIM) Hidalgo, Metztitlan , Pie de la Cuesta, 16 v 2010 , V. Ángeles. 1 female ( CAIM), Hidalgo, Zimapan , Benito Juárez, 03 vii 2009 , T. Reséndiz. 3 males ( CAIM), Guanajuato, Victoria , Cerrito Colorado, 23 iv 1999 , J. Sinecio. 1 male ( CAIM), Querétaro, Jalpan de Serra , n/d, L. Hernández . 1 male ( CAIM), Querétaro, Peñamiller , Cerrito Colorado, 12 viii 2010 , E. I. Conde Sánchez. 1 male ( CAIM), Querétaro, Peñamiller , El Carrizalito, 1 vii 2009 , S. León. 1 male ( CAIM), Querétaro, Toliman , Panales, 23 ix 2009 , N. Aparicio. 1 male ( CAIM), San Luis Potosí, Lagunillas , El Capulín, Laguna Verde, 17 vi 1995 , SSA. 1 male ( CAIM), San Luis Potosí, Lagunillas, El Mirador, 02 vi 1995 , SSA. 1 male ( CAIM), San Luis Potosí, Lagunillas, La Reforma , n/d, C. Balderas and L. Rodríguez . 1 male ( CAIM), San Luis Potosí, Lagunillas, Río Imihuan , 24 v 1997 , SSA.

Distribution. Mexico: Hidalgo, Guanajuato, Querétaro, and San Luis Potosí.

Comments. This species exhibits variability in the color pattern of the corium and connexival segments. Here we present diagnostic characters for one extreme of variation, the light phenotype ( Fig. 5E ), which is the color pattern originally described for T. mexicana ( Mazzotti 1940) . This phenotype seems common in the easternmost area of distribution of T. mexicana (for instance, specimens collected in the state of Hidalgo). The other extreme of color pattern variation, the dark phenotype ( Fig. 5C ), seems common in the westernmost area of the distribution of T. mexicana (for instance, specimens collected in the state of Guanajuato). Triatoma mexicana and T. gerstaeckeri are usually retrieved as sister species in molecular phylogenetic analyses ( Bargues et al. 2008; Espinoza et al. 2013; Rengifo-Correa et al. 2021). Besides, molecular studies reveal a close relationship of T. mexicana , plus T. gerstaeckeri , with several species of the T. phyllosoma species group ( Martínez et al. 2006; Bargues et al. 2008; Espinoza et al. 2013; De la Rúa et al. 2014; Rengifo-Correa et al. 2021). We think that the color pattern variability in T. gerstaeckeri and T. mexicana was inherited from their most recent common ancestor. No viable hybrids are retrieved from experimental crosses between T. mexicana with T. bassolsae , T. longipennis , T. mazzottii , T. pallidipennis , T. phyllosoma , and T. picturata ( Martínez-Ibarra et al. 2011b) . Experimental crosses of T. mexicana with other sympatric species, as T. dimidiata and T. gerstaeckeri , still need analysis.

Figures

FIGURE 5. Triatoma spp. A, T. longipennis; B, T. mazzottii; C, D, E. T. mexicana. F, T. pallidipennis.