Triatoma huehuetenanguensis Lima-Cordón, Monroy, Stevens, Rodas, Rodas, Dorn & Justi, 2019

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 : 345-346

Triatoma huehuetenanguensis Lima-Cordón, Monroy, Stevens, Rodas, Rodas, Dorn & Justi, 2019

( Figure 2 from Lima-Cordón et al. 2019)

Triatoma sp. aff. dimidiata group III Bargues, Klisiowicz, González-Candelas, Ramsey, Monroy, Ponce, Salazar-Schettino, Panzera, Abad-Franch, Sousa, Schofield, Dujardin, Guhl & Mas-Coma 2008: 10; Monteiro et al., 2018: 284.

Triatoma huehuetenanguensis Lima-Cordón, Monroy, Stevens, Rodas, Rodas, Dorn & Justi, 2019: 54 .

Diagnosis. Male body length 24.0– 26.4 mm. Female body length 23.9–28.5 mm. Anteocular region three times as long as postocular region. Postocular region with sides rounded, converging posteriorly. Ocelli large, lighter than tegument. First antennal segment does not attain level of apex of clypeus. Connections between each segment of the labium light-yellow colored, conspicuously contrasting with labium color.Anterior lobe rugose with distinguishable discal and lateral tubercles. Overall color of corium light yellow to yellow, with dark brown extreme apex and central spot of variable size. Membrane of hemelytra smoky brown, distinctly darker than corium. Overall color of connexival segments light yellow to yellow, with piceous or black spot-like dot on anterior third of segment. Venter light yellow. Spiracles concolorous with rest of tegument, not surrounded by dark spot. Pygophore almost squareshaped and darker than the rest of the tegument ( Fig. 7B ).

Specimens examined. None.

Distribution. Belize: Cayo; Guatemala: Huehuetenango and Petén; Honduras: Yoro; and Mexico: Campeche, Chiapas, Quintana Roo, and Yucatán. Wild hybrids of T. huehuetenanguensis and T. dimidiata are recorded in Campeche, Quintana Roo, and Yucatán ( Herrera-Aguilar et al. 2009). The type locality of this species is Huehuetenango, Guatemala ( Lima-Cordón 2019). Other localities recorded for the synonym Triatoma sp. aff. dimidiata group III came from specimens that were only identified with molecular data ( Dorn et al., 2009; Dorn et al. 2016; Monteiro et al., 2013).

Comments. Triatoma huehuetenanguensis (formerly T. sp. aff. dimidiata group III) was first detected as a cryptic species, considering its large genetic divergence and reciprocal monophyly in molecular phylogenies from T. dimidiata s.l. ( Marcilla et al. 2001; Bargues et al. 2008; Dorn et al. 2009; Monteiro et al. 2013). We could not examine specimens identified as T. huehuetenanguensis ; however, we examined several specimens of T. dimidiata from different localities of Mexico that have the diagnostic characters of T. huehuetenanguensis mentioned by Lima-Cordón et al. (2019). For instance, for T. dimidiata , the adjacent spot of abdominal spiracles ( Fig. 1E ) can be well developed to completely vanished, and the first antennomere attain level of apex of clypeus or does not. Size is neither a full discriminatory character, because we found small specimens of T. dimidiata (23 mm) in some localities of Veracruz. Considering the original description of T. huehuetenanguensis and morphological variation of examined specimens of T. dimidiata , we believe that the more distinctive characters for both species are the venter and labium coloration. All examined specimens of T. dimidiata have a venter largely piceous or black ( Fig. 2A ), in contrast with the light-yellow venter of T. huehuetenanguensis . For T. dimidiata , the coloration of the labium seems a low variable character, with most specimens exhibiting a uniform piceous or black labium. Only few specimens exhibit a light brown labium with connections slightly lighter than surrounding tegument ( Fig. 2A ). Instead, T. huehuetenanguensis has a piceous or black labium with light-yellow connections ( Fig. 1B ). We consider that the pattern of coloration of the labium and abdomen is clear enough to distinguish T. huehuetenanguensis from T. dimidiate ; however, we suggest checking the morphological and molecular evidence together for T. huehuetenanguensis identification. For details of taxonomic arrangements see comments on T. dimidiata . Spatially overlapping populations of T. huehuetenanguensis and T. dimidiata yield viable and fertile hybrids ( Herrera-Aguilar et al. 2009), but some non-overlapping populations appear to be inter-sterile ( García et al. 2013).

Figures

FIGURE 1. Morphology of Triatoma. A, Head of T. mopan, dorsal view (based on Dorn et al., 2018); B, head of T. huehuetenanguensis, ventral view (based on Lima-Cordón et al., 2019); C, pronotum and scutellum of Triatoma, dorsal view; D, abdomen of Triatoma, dorsal view; E, abdomen of T. mopan, ventral view.

FIGURE 2. Morphology of Triatoma. A, male of T. dimidiata, ventral view; B, corium of T. longipennis, dorsal view; C, corium of T. mazzottii, dorsal view; D, pronotum of T. mazzottii, lateral view; E, spongy fossulae of T. dimidiata.

FIGURE 7. Pygophore of Triatoma spp., ventral view. A, T. dimidiata; B, T. huehuetenanguensis; C, T. mopan. Credits of B, Lima-Cordón et al. 2019; C, Dorn et al. 2018.