Tylodinus canaliculatus, Champion, 1905

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 : 31-32

Tylodinus canaliculatus species group

Recognition. The species of this group are distinguished from other Tylodinus by having in combination the body robust and black and the hind and/or middle tibiae with an external tooth ( Figure 26 ).

Diagnosis. Body 1.9–2.1x longer than wide, black, clothed with dense, narrow to very narrow scales. Head and vertex with scales overlapping, similar in color, frons moderately concave; rostrum moderately convex and moderately robust, surface with large and deep (one species) or small and shallow (two species) punctures, similar in size to punctures on head, moderately carinate, apical area puncticulate; eyes moderately convex. Pronotum in lateral view moderately convex, outline with an anterior constriction, without a posterior constriction ( Figure 10 ), in dorsal view with sides slightly divergent from base to midlength, then convergent to apex, constricted beyond the middle ( Figure 14 ); weakly carinate (one species) or not carinate (two species); disc hollowed, moderately deep; punctures small and shallow, dense on the sides, becoming more spaced toward median section of disc, middle line sometimes smooth and glabrous ( Figure 15 ); clothed with light brown to yellow scales, very dense on lateral sides, flanks, and anterior area, forming a thick fringe longitudinally along middle and narrow strip that diverges from middle base to flanks, dark brown scales on middle and posterior areas of disc. Elytra black, sometimes dark red on intervals 1–2, basal margin sinuate, finely granulate, sometimes indistinct, stria 10 complete, interrupted near middle of elytra; clothed with dark brown to light brown scales; tubercle distribution as follows: I2 with a tubercle in front of the declivity, I3 with two tubercles: first tubercle subbasal and second tubercle on middle of elytral, I4 with two tubercles: first between tubercle on I3, second tubercle on base of declivity, I5 with two tubercles in same position as tubercles on I3 but smaller in size, I6 with two tubercles similar to tubercles on I4 but smaller in size, I7 with two tubercles similar to tubercles on I5, smaller in size, I9 with a subbasal swelling, tubercle on I2 longer (one species) or same size (two species) as tubercle on I4. Metasternum concave, glabrous on median section, metasternal tooth absent. Male abdomen with ventrites 3–5 not in same plane as 1–2, ventrite 1 concave, median section glabrous, ventrite 2 concave, as long (one species) or longer (two species) as 3–4 combined, with two transverse lines of scales along median section interrupted medially ( Figure 23 ), ventrite 5 longer than ventrite 1, with a median-anterior impression. Femora armed, hind femur almost reaching elytral apex, hind tibiae with an external tooth ( Figure 26 ), premucro absent. Male genitalia (not examined for T. canaliculatus ) with the median lobe in lateral view slender, weakly curved, as long as apodemes ( Figures 109–110 ); in ventral view with lateral sides straight, convergent, apex blunt; apical process in lateral view sinuate, moderately curved downward, in ventral view constricted beyond the median orifice, lateral sides subparallel. Female genitalia with tergite eight constricted, apex smooth, slightly curved and constricted, sternite eight doliform, median membranous area length as long (one species) to 2/3 (one species) as long as basal plate, spermatheca shallowly (one species) to very shallowly (one species) curved, ramus and nodulus indistinct.

Key to species of Tylodinus canaliculatus species group

1 Middle and hind tibiae with an external tooth ( Figure 26 )...................................................... 2

- Only hind tibiae with an external tooth................................................ T. canaliculatus Champion

2(1) Elytra with light brown or yellow scales on tubercles on interval 2 and in small patches along interval 3 on elytral declivity, remainder of elytral scales dark brown to black ( Figures 56– 57 )........................... T. triumforium Luna-Cozar

- Elytral scales of uniform color ( Figures 58–59 )....................................... T. sepulturaensis Luna-Cozar

Figures

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 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 100–109. Ventral and lateral habitus of median lobe: 100. Tylodinus andersoni, 101. Tylodinus cavicrus, 102. Tylodinus pseudocavicrus, 103. Tylodinus rugosus, 104. Tylodinus exiguus, 105. Tylodinus ixchel, 106. Tylodinus jonesi, 107. Tylodinus variabilis, 108). Tylodinus leoncortesi, 109. Tylodinus triumforium.

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.

FIGURES 52–59. Dorsal and lateral habitus: 52–53. Tylodinus coapillensis, 54–55. Tylodinus leoncortesi, 56–57. Tylodinus triumforium, 58–59. Tylodinus sepulturaensis.