Tylodinus mutabilis, Luna-Cozar & Anderson & Jones & León-Cortés, 2014

Luna-Cozar, Jesús, Anderson, Robert S., Jones, Robert W. & León-Cortés, Jorge L., 2014, A taxonomic monograph of the genus Tylodinus Champion (Coleoptera: Curculionidae: Cryptorhynchinae: Tylodina) of Chiapas, Mexico, Zootaxa 3788 (1), pp. 1-63 : 36

Tylodinus mutabilis species group

Recognition. The species of this group are distinguished from other Tylodinus by having in combination the pronotum in dorsal view weakly to feebly convex; elytra black, with dark red coloration at the base, along interval 2 and elytral declivity from interval 1 to interval 5, tubercles similar in size, scales yellow, dense on tubercles on intervals 1–5 at declivity base, and intervals 1–3 at middle of declivity ( Figures 64–65 ); metasternal tooth present ( Figure 19 ); hind tibiae with an external tooth ( Figure 26 ).

Diagnosis. Body 1.9–2.3x longer than wide. Head with punctures similar to punctures on rostrum, clothed with dark brown or light brown to yellow scales; vertex with whitish or yellow scales, or similar in coloration and tonality to head scales, uniformly distributed along vertex or in patch on middle of vertex, overlapping or dense to contiguous; frons moderately concave; rostrum moderately robust, moderately carinate, apical area puncticulate; eyes moderately convex, scales between eyes similar to scales on head or with a patch of yellow scales. Pronotum in dorsal view weakly to feebly convex ( Figures 65–67 ), outline with anterior constriction and without posterior constriction ( Figure 10 ) or with anterior and posterior constriction ( Figure 11 ); in dorsal view lateral sides slightly divergent from base to midlength, then convergent to apex, constricted beyond middle ( Figure 14 ), disc hollowed or somewhat hollowed, punctures dense to contiguous at base and progressively more widely spaced, smaller and shallower to apex, clothed with yellow scales, very dense on lateral sides and flanks, anterior area forming thick longitudinal fringe along middle and narrow strip that diverges from middle base to flanks, and with dark brown scales on middle and posterior areas of disc, occasionally with whitish scales intermixed. Elytra black, with dark red coloration at base, along interval 2 and elytral declivity from interval 1 to interval 5 ( Figures 64–65 ); tubercle distribution as follows: I2 with tubercle on base of declivity, I3 with two tubercles: first tubercle subbasal, second tubercle on middle of elytra, I4 with two tubercles: first tubercle small, positioned between tubercles on I3, second tubercle on base of declivity, similar in size or longer than tubercle on I2, I5 with two tubercles in same position as tubercles on I3, I7 with very small subbasal tubercle, tubercles weak, more or less homogenous in size; elytra with patch of yellow scales, dense on tubercles on intervals 1–5 at declivity base, and intervals 1–3 along declivity. Metasternum concave or flat, glabrous in median section, metasternal tooth present. Male abdomen concave or feebly concave, glabrous in median section; ventrite 2 feebly concave, as long as 3–4 combined, glabrous in median section or with a transverse line of scales along median line; ventrite 5 flat, longer than ventrite 1, with median-anterior impression. Femora armed, hind femur length reaching elytral apex, hind tibiae with external tooth ( Figure 26 ), premucro present or absent. Male genitalia ( Figures 113–114 ) with median lobe in lateral view weakly curved, stout or moderately stout, in ventral view as long as half length of apodemes, swollen at sides beyond 0.27 from base, subparallel, apex acute; apical process in lateral view large (0.35–0.42 as long as median lobe) or moderately large (0.26–0.34 as long as median lobe), slightly curved or sinuate, abruptly or moderately curved downward, in ventral view constricted beyond median orifice or not, lateral sides convergent to apex, in one species sharply widened subapically and immediately converging to the apex (triangle shaped).

Key to species of Tylodinus mutabilis species group

1 Base of the elytral declivity with tubercle on interval 2 smaller than tubercle on interval 4; ventrite 2 with median section glabrous ( Figures 66–67 )................................................................. T. parvus Luna-Cozar

- Base of the elytral declivity with tubercle on interval 2 similar in size to tubercle on interval 4, ventrite 2 with a transverse line of scales along median section ( Figures 64–65 )............................................ T. mutabilis Luna-Cozar

Figures

FIGURES 60–67. Dorsal and lateral habitus: 60–61. Tylodinus lum, 62–63. Tylodinus spiniventris, 64–65. Tylodinus mutabilis, 66–67. Tylodinus parvus.

FIGURES 12–19. 12. Tylodinus pusillus head a) male, b) female. 13–14. Dorsal habitus of pronotum showing the lateral side of pronotum 13. Tylodinus andersoni, 14. Tylodinus porvenirensis. 15–17. Dorsal habitus: 15. Tylodinus rugosus, 16. Tylodinus exiguus, 17. Tylodinus jonesi. 18. Tylodinus coapillensis note tubercle on elytra declivity base, 19. Tylodinus elongatus showing metasternal tooth.

FIGURES 20–27. 20–21. Tylodinus spiniventris: 20. meso- and metathorax (male) 21. ventrite 5 (female), 22. Tylodinus elongatus ventrite 5 (female), 23. Tylodinus triumforium, ventrite 2 (male). 24. Tylodinus complicatus, ventrite 2 (female). 25. Tylodinus complicatus, ventrite 2 (male), 26. Hind tibia of Tylodinus triumforium, 27. Front tibia of Tylodinus rugosus.

FIGURES 1–11. 1–5. Dorsal outline: 1. Generalized Tylodinus, indicating terminology used in this study. Key: letters indicate areas of pronotum. A, anterior area; B, median area; C, posterior area; a, anterior of lateral area; b, median section of lateral area; c, median section of dorsal area; d, anterior section of dorsal area; e, posterior section of lateral area; f, posterior section of dorsal area. 2. Tylodinus variabilis, note elytra basal margin straight. 3. Tylodinus ixchel, note elytra basal margin slightly sinuate. 4. Tylodinus immundus, note elytral basal margin sinuate. 5. Tylodinus elongatus, note elytra basal margin very sinuate. 6–11. Lateral outline: 6. Tylodinus complicatus, male, note ventrites 3–5 in same plane as ventrites 1–2. 7. Tylodinus variabilis, male, note ventrites 3–5 not in same plane as ventrites 1–2. 8. Tylodinus coapillensis, female, note ventrites 1–2 strongly convex, ventrites 3–5 not in same plane as ventrites 1–2. 9. Tylodinus zilchi (schematic). 10. Tylodinus sepulturaensis (schematic) 11. Tylodinus rugosus (schematic).

FIGURES 110–119. Ventral and lateral habitus of median lobe: 110. Tylodinus sepulturaensis, 111. Tylodinus lum, 112. Tylodinus spiniventris, 113. Tylodinus mutabilis, 114. Tylodinus parvus, 115. Tylodinus pusillus, 116. Tylodinus porvenirensis, 117. Tylodinus elongatus, 118. Tylodinus complicatus, 119. Tylodinus rufus.