Tylodinus 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 : 6-12

Tylodinus Champion 1905

Tylodinus Champion, 1905:464 ; Fiedler 1940: 299–300; Blackwelder 1947:860 (checklist); Kuschel 1956: 323 (new species); O'Brien and Wibmer 1982:139 (checklist); Alonso-Zarazaga & Lyal 1999:134 (catalog).

Type species. Acalles nodulosus Boheman 1837:330 , by original designation. Gender masculine.

Diagnosis. Distinguishable among Tylodina by the metepisternum distinctly visible; the elytra clothed with elongate scales, moderately dense to sparse, more dense on the middle of disc and on the base, becoming more scattered toward the flanks; intervals weakly convex, less convex to flat toward the flanks; striae shallow, tubercles round or laminate; internal sac of male genitalia with diminutive round and acute sclerites.

Description. Length 2.0– 11.5 mm. Width 0.9–7.0 mm. Body oblong-ovate, 1.8–2.7x longer than wide, clothed with elongate scales, short or long. Head with red, dark red or black integument; scales on vertex dense to contiguous or overlapping, same color as head scales, yellow, light brown or whitish; frons concave to moderately concave; rostrum moderately robust or narrow, surface moderately carinate to rugose, punctures small or large, deep or shallow, longer or as long as head punctures, with an apical area glabrous (male with apical 1/2, female with apical 2/3 ( Figure 12 )), puncticulate (very fine and widely spaced punctures), punctate (fine impressed punctures) or smooth; antennal scape in resting position not reaching anterior margin of eye, funicle with articles 1 and 2 subequal in length, articles 3–4 slightly longer than wide, articles 5–7 submoniliform; eyes separated by about the width of an eye, moderately convex or flush with outline of head. Pronotum with red or black integument; in lateral view with one of three patterns: 1) outline with anterior constriction and without posterior constriction ( Figure 10 ), 2) outline with anterior and posterior constrictions ( Figure 11 ), and 3) outline slanting downward from highest point to the apex and the base ( Figure 9 ), feebly, moderately or strongly convex; in dorsal view widest at about midlength; with one of two patterns: 1) sides slightly divergent from base to midlength, then convergent to apex, constricted beyond the middle on the sides ( Figure 14 ), or 2) similar to previous pattern but not constricted beyond the middle ( Figure 13 ); apical margin in lateral view extended over hind portion of head; disc with one of four patterns: 1) deeply excavate ( Figures 28, 30, 32 ), 2) distinctly hollowed ( Figures 34 , 38 , 76 ), 3) somewhat hollowed ( Figures 64, 66 , 78 ), or 4) lacking impressions ( Figures 44, 48 ); surface smooth, weakly carinate to rugose, without granules or granulate, with large ( Figure 16 ), medium ( Figure 14 ) or small punctures ( Figure 17 ), deep or shallow, with one of two patterns: 1) contiguous at the base and progressively more widely spaced, smaller and shallower to the apex ( Figures 14, 16 and 17 ), or 2) dense to contiguous on lateral sides, progressively more widely spaced and less conspicuous in the median, anterior and posterior sections ( Figure 15 ); scales sparse, moderately dense to dense, distributed in one of three patterns: 1) light scales (generally yellow, light brown or white) very dense on lateral sides and flanks, anterior area and forming a thick longitudinal fringe along the middle and a narrow strip that diverges from the middle base to the flanks, and with dark scales on the middle and posterior areas of the disc (dark brown or black) ( Figures 14, 17 ), occasionally the pattern is not well defined ( Figure 48 , 56 , 78 ), 2) similar to last pattern but without dark brown scales ( Figure 76 ), and 3) when excavation is present, scales dense on edge of pronotal excavation, more widely separated towards lateral and median areas of disc ( Figures 28, 30, 32 ); scales dense ( Figure 78 ), moderately dense ( Figure 64 ) to scattered ( Figure 76 ). Elytra with the basal margin straight to very sinuate ( Figures 2–5 ); widest just posterior to basal margin then convergent to apex; apex narrowly truncate, clothed with sparse to moderately dense scales, more dense on middle of disc and on base, becoming more scattered toward the flanks; elytral declivity with scales denser on interval 1–2 ( Figures 56–57, 58–59 , 72–73 , 76–77 ) or with dense patch on intervals 1–3 ( Figures 46–47 , 74–75 ) and on intervals 1–5 ( Figures 48–49 , 78–79 ) at base of declivity, base with scales similar those of disc or with light brown or white scales on tubercles or only on first tubercle; integument color with one of three patterns: 1) black ( Figures 52–63 ), 2) black with red coloration at the base and along intervals 1–2 and on declivity of intervals 1–5 ( Figures 74–77 ), and 3) black with red coloration at the base and along middle line, elytral declivity and flanks ( Figures 44–51 , 64–65 ). Intervals weakly convex, less convex to flat toward flanks, intervals 2, 3, 7, 8 and 9 convex on declivity near apex; striae shallow; stria 10 complete, incomplete or absent; tubercles on elytra disc variously developed, laminate ( Figures 29, 31, 33 ) or round; declivity with tubercle on interval 4 laminate ( Figures 29,31, 33 and 97 ), acute ( Figure 18 ) or round; tubercle on interval 2 absent, longer, smaller or same size as tubercle in same position at interval 4; surface with or without granules. Scutellar shield absent. Wings absent. Metasternum concave, moderately concave or flat, glabrous on median section or squamous; metepimeron visible; metasternal tooth present ( Figure 19 ) or absent. Abdomen with scales narrow and elongate ( Figure 20–25 ), scales wider, longer and dense at sides; male with ventrites 3–5 in same plane as ventrites 1–2 or not ( Figures 6–7 ); female with ventrites 3–5 not in same plane as 1–2 ( Figure 8 ); ventrite 1 concave, moderately concave, feebly concave or weakly convex, glabrous on median section, squamous or with scattered scales or with an anterior fringe of scales; ventrite 2 feebly concave, concave or weakly convex, longer than or as long as ventrites 3–4 combined, glabrous ( Figure 25 ), or with two transverse lines of scales interrupted medially ( Figure 23 ) or not interrupted, female of some species with transverse line of scales interrupted medially ( Figure 24 ); female with ventrites 1–2 strongly convex; ventrites 3–4 squamous; ventrite 5 convex along median line or convex at anterior 1/2 and flat on posterior 1/2 or flat, as long or longer than ventrite 1, with one of three patterns: 1) with an apical impression, 2) with apical and lateral impression or 3) without impression, in some species, female with acute projections ( Figures 21–22 ). Legs narrowly elongate (3.6–5 x longer than wide); with feeble punctures or densely, deeply punctuate throughout, punctures elongate-oval and linearly arranged giving legs (especially femora) a striated appearance, with fine granules between punctures; hind femur with length variable, from not reaching elytral apex to reaching beyond the elytra apex; femora armed with a small, distally inclined tooth ventrally or unarmed; middle and hind tibiae with outer margin subparallel or an external tooth ( Figure 26 ); front tibia straight to sinuate or very deeply excavate apically ( Figure 27 ); premucro present or absent. Genitalia greatly varied, male with median lobe in lateral view with curvature and width varied, from weakly to strongly curved, very slender to stout, apex straight to abruptly curved downward; width of apical process very slender to robust; apical process form almost linear, slightly curved, sinuate or curved upward; occasionally with a longitudinal notch on lateral base. Median lobe length in ventral view from longer than to ½ as long as the length of the apodemes, sides straight or convex near the base (less than of 0.25 of length from the base) to near the middle (>0.27 to 0.5 of length from the base), convergent (base of median lobe wider than subbasal portion of apex), divergent (subbasal portion of apex wider than base of median lobe) or subparallel (base of median lobe as wide as subbasal portion of apex), apex of median lobe acute ( Figure 98d–e ), truncate ( Figure 98c ) or blunt ( Figure 98a ); apical process constricted beyond the median orifice ( Figure 98a,c,d–e ) or not, sides sub-parallel, convergent and sometimes rhomboid-shaped subapically ( Figure 98e ). Female with tergite eight trapezoidal or constricted, apex invaginate, obtuse or slightly curved; sternite eight oblong, doliform, or trapezoidal, with the length of median membranous area from 1/3 as long as basal plate to subequal in length, spermatheca very broad to very shallowly curved, corpus convex to slightly convex, ramus and nodulus distinct or indistinct.

Comments. Members of this genus can be confused with other genera of the subtribe Tylodina that also have tuberculate elytra, such as Tylodes , Xenosomus , or Phymatophosus . Species of Tylodinus are most commonly confused with Acalles , because so many species were erroneously originally placed in this genus (Champion 1904, O´Brien and Wibmer 1982); however, the metepisternum of these genera is not externally visible, and this character separates these genera from Tylodinus . Fiedler (1940) placed Tylodinus near Canistes and Pseudoacalles because these genera have the metepisternum distinctly visible, but other characters given in the diagnosis will separate Tylodinus from Canistes and Pseudoacalles . In a forthcoming paper on the phylogenetic relationships of Tylodinus , a number of new genera, closely related to Tylodinus , will be described.

Derivation of generic name. C hampion (1905) did not indicate the derivation of the name Tylodinus but it appears to be derived from the combination of two words: Tylodes = derived from Greek “ tylodes ” = tubercle, probably referring to the tubercles on the body of the genus Tylodes and from the Latin suffix inus = like; Tylodinus = like a Tylodes . The name refers apparently to possible confusion between Tylodinus and Tylodes .

Natural history. Very few details are available on the natural history of any species of Tylodinus . Adults have been collected almost exclusively in Berlese or Winkler extractions of sifted leaf litter and other ground substrate debris. Some specimens have been collected beating dead vegetation and numbers of larger-sized species have been hand collected on dead wood, apparently in association with Xylariaceae fungi, especially those with the crustose fruiting bodies, which the black, tuberculate body form of the weevil greatly resembles. Immature stages are unknown. Given what is known of the habits of related taxa, it is likely that the larvae mine in dead, decaying wood or other plant debris on the forest floor. Nearly all species are associated with a variety of montane wet forest habitats.

Distribution. Tylodinus occur throughout the Sierra Madre Oriental from Tamaulipas south to Panama with many species undescribed. At present, 20 species have been described with an additional 32 species described herein, and numerous other new species from other geographic areas are known. Thus, at present there 52 species known to date, 40 are known to occur in México and of these, 38 species have only been recorded from México and two extend from México south into Central America. As discussed, Tylodinus species in Chiapas are well sampled and were collected at elevations from 1080 to 2970 m in 20 municipalities; the species numbers in these municipalities are detailed in Table 1 .

Checklist of included species

Figures

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 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 28–35. Dorsal and lateral habitus: 28–29. Tylodinus nodulosus, 30–31. Tylodinus zilchi, 32–33. Tylodinus andersoni, 34–35. Tylodinus cavicrus.

FIGURES 36–43. Dorsal and lateral habitus: 36–37. Tylodinus pseudocavicrus, 38–39. Tylodinus rugosus. 40–41. Tylodinus buchanani. 42–43. Tylodinus exiguus.

FIGURES 76–83. Dorsal and lateral habitus: 76–77. Tylodinus rufus, 78–79. Tylodinus dominicus, 80–81. Tylodinus noctis, 82–83. Tylodinus kuscheli.

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

FIGURES 44–51. Dorsal and lateral habitus: 44–45. Tylodinus ixchel, 46–47. Tylodinus jonesi, 48–49. Tylodinus wibmeri, 50–51. Tylodinus variabilis.

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

FIGURES 68–75. Dorsal and lateral habitus: 68–69. Tylodinus pusillus, 70–71. Tylodinus porvenirensis, 72–73. Tylodinus elongatus, 74–75. Tylodinus complicatus.

FIGURES 92–99. 92–99. Dorsal and lateral habitus: 92–93. Tylodinus gibbosus, 94–95. Tylodinus kissingeri, 96–97. Tylodinus pinguis. 98. Median lobe apex of: a) Tylodinus elongatus, b) Tylodinus exiguus, c) Tylodinus pseudocavicrus, d) Tylodinus rufus, e) Tylodinus rufus (squashed), 99. Tylodinus zilchi, ventral and lateral habitus of median lobe.

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.