Rhodnius micki, Zhao & Galvão & Cai, 2021

Zhao, Yisheng, Galvao, Cleber & Cai, Wanzhi, 2021, Rhodnius micki, a new species of Triatominae (Hemiptera, Reduviidae) from Bolivia, ZooKeys 1012, pp. 71-93 : 71

Rhodnius micki sp. nov.

Type materials.

Bolivia: Santa Cruz, Saavedra, C.J. Pruett [leg.], 1 male holotype, 10.v.1989, 1 male paratype, 1.iii.1989 (NMHUK).

Diagnosis.

General coloration dark brown. Head relatively short, only slightly longer than the pronotum. Eyes small, width of the eye shorter than the synthlipsis. Central area of the anterior lobe of the pronotum conspicuously dark and its humeral angle of the posterior lobe relatively sharply curved. Legs brown. The median process of the pygophore long and bifid on the tip. The medial basal sclerite of the phallosoma with two straight and flat projections. One distal dorsal sclerite of the endosoma bifurcated, and its tip rounded and curved slightly inward.

Description.

Coloration. Body generally dark brown. Head with light median longitudinal stripe extending from the apex of clypeus to the posterior portion of ocelli; eyes blackish; middle of third segment and posterior half of forth segment yellow; a pair of black stripes on the dorsal surface of neck, half of lateral side and ventral side dark. Pronotum with a pair of submedian carinae and lateral margin yellow; concave areas on anterior lobe, especially the central area darkened; posterior lobe dark with scattered irregular small yellow spots. Scutellum dark with a yellow “Y” -shaped ridge; the tip of scutellar process white. Hemelytra generally brown and mottled; corium with small lightly colored spots; membrane with narrowly rimmed pale-yellow veins, area between veins with scattered light color spots. Legs mottled with yellow spots; tarsi yellowish (Fig. 7 ). Connexivum dark and mottled with yellow spots, posterior one fourth of every segment almost yellow; ventral surface of the abdomen yellowish with scattered irregular dark brown spot; sternites light brown to black, with irregular dark brown spots, center of sternite II and a pair of sublateral elliptical spots of each segment dark (Fig. 9 ); spiracles with a brown narrowly margin (Fig. 8 ).

Structure.

Head. Elongated and granulose, almost 2.5 × as long as width across eyes (1:2.6-2.59), slightly longer than length of pronotum (1:1.17-1.21); apex of maxillary plate surpassing clypeus; anteocular region ~ 3 × as long as postocular region in length (1: 2.84-3.15); eyes small, width of eye in dorsal view shorter than synthlipsis (1:0.60); in lateral view, eyes far away from upper surface of head and approaching to lower surface; ratio of antennal segments 1:5.11-6.29:4.66-5.14:3.55-4.43; first labial segment proceeding toward antenniferous tubercle and second labial segment approaching to posterior margin of head. Ratio of labial segments 1:2.78-3.13:0.61-0.83. Thorax. Anterolateral angles triangle-like. Surface of pronotum granulose, length of posterior pronotal lobe ~ 2 × as that of anterior lobe (1:1.89-1.93); posterior pronotal lobe ~ 1.5 ×as wide as anterior lobe (1:1.52-1.74); median longitudinal furrow of anterior lobe deep on the median transverse furrow; humeral angles sharply curved relatively to other species of Rhodnius (Fig. 10 ). Scutellum triangular with a yellow Y-shaped ridge; subapical portion with a cone-shaped process. Pleura of meso- and metathoraxes winkled. Legs long and slender. Hemelytra approaching tip of abdomen. Male genitalia (Figs 12 - 26 ). Pygophore (Figs 12-14 ) globular with a tubercle on the bottom of the ventral surface (Fig. 13 ); transverse bridge of pygophore (TBPy) strongly sclerotized and narrow; a pair of dorsal sclerites of genital opening (DSPr) large; median process of pygophore (MPPy) long, bifid at apical portion and tilting 45 degrees to the dorsal side in lateral view. Parameres (Figs 15 , 16 ) strongly curved at apex and with a denticle. Basal plate (BP) hexagonal in dorsal view, diameter of the arms similar to that of the transverse bridge of basal plate (TBBP) (Fig. 17 ); basal plate extension (BPE) short and approximately half shorter to arms of basal plate in length (Figs 18 , 21 ); dorsal phallothecal sclerite (DPS) flat, as a subrectangular with round angles; medial basal sclerite of phallosoma (MBSPh) bifid with two straight and flat projections (Figs 17 , 18 , 20 , 21 ), and both of them slightly swelled at base; lateral flap-like prolongation of phallosoma (LFPPh) large (Figs 17-22 ); two ventral sclerites of phallosoma (VSPh) elongated ovoid (Figs 17-22 ); the tip of non-everted phallus slightly sclerotized on the dorsal and lateral surface, and the surface of the phallosoma with indistinct stripes (Figs 17 , 18 ); distal dorsal sclerite of endosoma (DDSEn) bifurcated, tips rounded, and curved inward lightly (Figs 20 , 21 , 24 ); distal ventral sclerite of the endosoma (DVSEn) smaller than the dorsal sclerite and bifurcated with two projections set far apart (Figs 21-23 ). The membrane of endosoma on the dorsal surface wrinkled and a bit thicker than other part of membrane.

Etymology.

The species epithet is named in honor of Mr. Mick Webb (NHMUK), who had helped us in many ways in the study of Hemiptera .

Measurements.

[in mm, ♂ (n = 2)] Total length to tip of abdomen 17.20-17.33. Length of head (exclude neck) 3.21-3.55; width of head 1.40-1.43; length of anteocular 2.27-2.30; length of postocular 0.73-0.80; width of eye 0.40-0.44; length of synthlipsis 0.67-0.73. Length of antennal segments I-IV=0.35-0.45/2.20-2.30/1.80-2.10/1.55-1.60; length of visible labial segments I-III=0.80-0.90/2.50/0.60. Length of anterior lobe of pronotum 0.90-0.93; length of posterior pronotal lobe 1.70-1.93; width of anterior pronotal lobe 2.30-2.33; width of posterior pronotal lobe 4.00-4.15. Length of scutellum 1.70-1.75; width of scutellum 1.80-1.90; length of hemelytron 10.40-10.50. Width of abdomen 5.35-5.40. (all the former numbers are for holotype, except length of total, anteocular, second and fourth segment, and width of abdomen).

Additional material.

Rhodnius robustus Larrousse, 1927 (1♂, Brazil: Belém, Instituto Evandro Chagas, reared in lab, 20.II.1992) (NHMUK).

Geometric morphometrics

(Figs 27 , 28 ) On the one hand, R. pictipes and R. stali appear to be the most morphologically similar species to R. micki sp. nov. having relatively short head, only slightly longer than the pronotum, and a defined transverse sulcus on their pronotum. On the other hand, Rhodnius ecuadoriensis , R. pallescens , and R. micki sp. nov. do not have dark rings on the tibiae which is a significant diagnostic character of Rhodnius . Based on the morphometrics of the head and the particular coloration of the legs, we compared before mentioned four species to R. micki sp. nov. For head shape analysis (Fig. 27 ), the contribution of the first principal (PC1) component accounted for 81.79% of the total variation, whereas the second principal component (PC2) accounted for 6.26%. In the factorial map, five species were separated. The type specimens of R. micki sp. nov. were far away from the others. The thin plate spline visualization showed that the fifth and tenth landmarks located on the anterior margin of eye contributed most to the shape difference among these species. The size of the eye and the length of the anteocular and postocular regions might be the most significant differences among them. For wing vein analysis (Fig. 28 ), the contribution of the first principal (PC1) component accounted for 58.46% of the total variation and the second principal component (PC2) accounted for 22.21%. The points of R. micki sp. nov. were also distinct from those of the other four species, and these four species were separated from each other too. The thin plate spline visualization showed that the seventh landmark contributed most to the shape difference among these species. It implied that the position of the intersection of the Cu and An1 veins may be the most variable among them.

Figures

Figures 7 - 11. 7 - 9 holotype of Rhodnius micki sp. nov. 11 Rhodnius stali Lent, Jurberg & Galvao, 1993 7 dorsal side 8 lateral side 9 ventral side 10, 11 pronotum. Scale bars: 5.00 mm (7 - 9); 1.00 mm (10, 11)

Figures 12 - 16. Pygophore and paramere of paratype of Rhodnius micki sp. nov. 12 - 14 pygophore 12 dorsal view 13 lateral view 14 ventral view 15, 16 paramere: 15 dorsal view 16 lateral view. Scale bars: 1.00 mm. Abbreviations: DSPr dorsal sclerites of pygophore MPPy Median process of pygophore TBPy Transverse bridge of pygophore.

Figures 17 - 26. Pallus 17 - 24 Rhodnius micki sp. nov. 25, 26 Rhodnius robustus 17 - 19 non-everted phallus 20 - 26 everted phallus 17, 20 dorsal side 18, 21 lateral side 19, 22 ventral side 23, 25 distal ventral sclerite of endosoma 24, 26 distal dorsal sclerite of endosoma. Scale bars: 1.00 mm (11 - 16); 0.50 mm (17 - 20). Abbreviations: BP basal plate TBBP transverse bridge of basal plate DPS dorsal phallothecal sclerite MBSPh medial basal sclerite of phallosoma LFPPh lateral flat-like prolongation of phallosoma VSPh ventral sclerite of phallosoma BPE basal plate extension DDSEn distal dorsal sclerite of endosoma DVSEn distal ventral sclerite of the endosoma AA articulatory apparatus Ph phallosoma En endosoma.

Figures 27, 28. Morphological variations of five Rhodnius species based on Principal Component Analysis. The 90 % equal frequency ellipses containing approximately 90 % of the data points are shown. The thin-plate splines show the average shape for each species, corresponding to the deformation of the landmarks compared with the origin (the average shape of all species) 27 head 28 fore wing.