Trachyphloeini, Lacordaire, 1863

Borovec, Roman & Skuhrovec, Jiří, 2019, Two new genera of Trachyphloeini with a key to the genera of small terricolous South African Trachyphloeini and Embrithini (Coleoptera: Curculionidae: Entiminae), Zootaxa 4695 (5), pp. 451-476 : 464-474

Key to the genera of small terricolous species of Trachyphloeini with connate claws and Embrithini

This key includes all Trachyphloeini genera with connate claws and for completeness also genera of the Embrithini, containing species with a terricolous life style and smaller than 4.0 mm. In the key, only the genus Cosmorhinus Schoenherr, 1826 is missing, due to its unclear systematic position, which should be solved in some future paper, but three known Cosmorhinus species will clearly key to the Ellimenistes in the table below.

The reason for including genera of both tribes in one key is purely practical. The tribes are distinguishable only by the presence (Embrithini) or absence ( Trachyphloeini ) of the metatibial corbels. This character is easily observed in moderately larger specimens as in Afrophloeus or Ellimenistes species, but it is sometimes difficult to see in smaller specimens, especially if the corbel is slender and specimens are encrustated by soil.

1. Rostrum continuous with head, completely flat, without any transverse sulcus ( Figs 2B , 3B , 7B , 8B ).................... 2

- Rostrum and head separated by narrow sulcus or deep transverse furrow ( Figs 5B , 9–15B )............................ 4

2. Rostrum 1.1–1.3 × wider than long ( Figs 7B, C ). Frons glabrous and deepened ( Fig. 7B ). Epistome projecting anteriorly and laterally forming sharp teeth directed dorsally ( Fig. 7B ). Epifrons with distinctly concave sides ( Fig. 7B ). Antennal scrobes in lateral view reaching about the half distance from antennal insertion to eyes ( Fig. 7A ). Elytra behind base constricted ( Fig. 7A ). Protibiae 5.5–6.4 × as long as wide at widest point ( Fig. 7D ). Apex of plate of female sternite VIII with the Y-shaped process ( Fig. 7F ). Spermatheca without differentiated nodulus and ramus. Size 1.6–2.6 mm ....... Epistomius Borovec & Skuhrovec

- Rostrum 1.5–1.9 × wider than long ( Figs 2B, C , 8B, C ). Frons densely squamose, flat ( Figs 2B , 3B , 8B ). Epistome not projecting anteriad ( Figs 2B , 3B , 8B ). Epifrons with straight sides ( Figs 2B , 3B , 8B ). Antennal scrobes in lateral view reaching eyes ( Figs 2A , 3A , 8A ). Elytra not constricted behind base ( Figs 2A , 3A , 8A ). Protibiae 3.2–4.2 × as long as wide at widest point ( Figs 2E , 3E , 8D ). Plate of female sternite VIII without apical process ( Fig. 8F ). Spermatheca with differentiated nodulus and ramus ( Fig. 1F )....................................................................................... 3

3. Protibiae with distinct, sparse, laterally prominent spines reaching midlength of lateral edge ( Figs 2E , 3E ). Anterior border of pronotum in lateral part dentiform ( Figs 2A , 3A ). All tibiae mucronated. Suture between abdominal ventrites 1 and 2 arched ( Fig. 1E ). Ventrite 1 in middle about as long as ventrites 2–4 combined ( Fig. 1E ). All ventrites densely squamose ( Fig. 1E ). Tegmen with slender ring lacking parameres. Size 1.2–1.7 mm ............ Barclayanthus Borovec & Skuhrovec , gen. nov.

- Protibiae with fringe of dense slender bristles only at apical portion ( Fig. 8D ). Anterior border of pronotum straight ( Fig. 8A ). All tibiae amucronated. Suture between abdominal ventrites 1 and 2 sinuate ( Fig. 8G ). Ventrite 1 in middle slightly shorter than ventrite 2 ( Fig. 8G ). All ventrites glabrous, sparsely covered with semiappressed spatulate scales ( Fig. 8G ). Tegmen with ring expanded to the tegminal plate ( Fig. 8E ). Size 1.5–2.1 mm ......................... Afromuelleria Borovec & Skuhrovec

4. Tarsi with a single claw, or exceptionally with one claw elongate and with trace of second rudimentary claw ( Fig. 9A ). Size 1.6–2.8 mm ............................................................................ Heisonyx Marshall

- Tarsi with two, equally long claws........................................................................ 5

5. Epifrons between antennal insertion very slender, 0.2–0.3× as wide as rostrum in the same place ( Fig. 10B ). Scapes very long and slender, reaching clearly behind midlength of pronotum when folded, 11–12× as long as at apex wide ( Fig. 10A ). Funicle segment 2 long and slender, 3.5–6.5× longer than wide and usually twice or more longer than segment 1 ( Fig. 10A ). Metatibiae with wide squamose metatibial corbels. Female sternite VIII with long and slender apodeme, 3.5–4× as long as small, subtriangular plate, with slender but developed anterior as well as posterior margins ( Fig. 10F ). Size 2.4–7.8 mm ................................................................................................... Ellimenistes Boheman

- Epifrons between antennal insertion wide, at least 0.5× as wide as rostrum in the same place ( Figs 5B , 11–15B ). Scapes moderately long or short and robust, at most 8× as long as at apex wide ( Figs 5A , 11–15A ). Funicle segment 2 short to moderately long, at most 3.0× longer than wide and usually equally long as segment 1 or shorter ( Figs 5A , 11–15A ). Metatibiae with or without corbels. Female sternite VIII with short apodeme, at most twice as long as umbrella-shaped plate, with posterior margin membraneous (with exception of Lalagetes , having similar sternite VIII as Ellimenistes ) ( Figs 4G , 11–15F )............. 6

6. Rostrum separated from head by a wide transverse sulcus with ill-defined borders ( Fig. 11B ). Eyes small and flat, hardly visible in dorsal view ( Fig. 11C ). Scapes short, wide and robust, at most 4.0× longer than wide at widest place ( Fig. 11A ). Funicles robust, all segments distinctly wider than long ( Fig. 11A ). Clubs barely wider than last funicle segment and approximated to it ( Fig. 11A ). Protibiae armed with 7 sparse spines of different length and shape ( Fig. 11D ). Size 2.3–3.3 mm ...................................................................................... Afrophloeus Borovec & Oberprieler

- Rostrum separated from head by narrow, sharply edged transverse sulcus ( Figs 5B , 12–15B ). Eyes small or large, convex, clearly visible in dorsal view ( Figs 5C , 12–15C ). Scapes long and slender, at least 3.9× longer than wide at widest place, only in some Pentatrachyphloeus species short and robust ( Figs 5A , 12–15A ). Funicles slender, at least first five segments longer than wide, only in some Pentatrachyphloeus all segments wider than long ( Figs 5A , 12–15A ). Clubs distinctly wider than and distinctly separated from last funicle segment ( Figs 5A , 12–15A ). Protibiae fringed by fine setae or short, dense, inconspicuous spines ( Figs 5E , 12–15D )............................................................................... 7

7. Rostrum and head separated by wide and deep transverse furrow ( Fig. 5B ). Protibiae with mucro and 2 mesally curved premucros at apex ( Fig. 5E ), meso- and metatibiae with 2 mesally curved equally long spines. Metaventral process distinctly wider than transverse diameter of metacoxa. Gena glabrous ( Figs 5B, C ). Size 1.9–2.4 mm ................................................................................................... Janakius Borovec & Skuhrovec , gen. nov.

- Rostrum and head separated by slender and shallow, V-shaped sulcus ( Figs 12–15B ). Pro-, meso- and metatibiae with 1 mesally curved mucro ( Figs 12–15D ). Metaventral process narrower than transverse diameter of metacoxa. Gena densely squamose ( Figs 12–15B, C )...................................................................................... 8

8. Epifrons at base as wide as space between eyes ( Figs 12B , 13B ). Frons very short, densely squamose ( Figs 12B , 13B ). Epistome small, dorsally hardly visible ( Figs 12B , 13B ). Protibiae short and robust, 3.6–5.2 × as long as wide ( Figs 12D , 13D ). Apical surface of metatibiae at least partly squamose. Female sternite VIII with umbrella-shaped plate lacking pointed tip or arms, with ill-defined posterior border ( Figs 12F , 13F )................................................................. 9

- Epifrons at base narrower than space between eyes ( Figs 14B , 15B ). Frons short, glabrous ( Figs 14B , 15B ). Epistome large and distinct, well visible dorsally ( Figs 14B , 15B ). Protibiae long and slender, 5.5–6.7 × as long as wide ( Figs 14D , 15D ). Apical surface of metatibiae glabrous. Female sternite VIII with narrow plate either with clearly developed posterior border or lacking it, then with sharply pointed tip and longitudinal arms ( Figs 14F , 15F )........................................... 10

9. Metatibiae lacking corbels. Ventrite 2 longer than ventrite 3 or 4 ( Fig. 12G ). Suture between ventrite 1 and 2 straight ( Fig. 12G ). Elytra lacking laterally prominent subhumeral calli ( Fig. 12A ). Rostrum in males identical to those in females. Size 1.4–2.6 mm .............................................................................. Pentatrachyphloeus Voss

- Metatibiae with wide or narrow corbels. Ventrite 2 as long as ventrite 3 or 4 ( Fig. 13G ). Suture between ventrite 1 and 2 distinctly arched ( Fig. 13G ). Elytra with subhumeral calli visible either dorsally or in dorsolateral view ( Fig. 13A ). Rostrum in males in some species in apical part abruptly enlarged. Size 2.7–5.4 mm ....................... Glyptosomus Schoenherr

10. Epifrons at base distinctly narrower than space between eyes, between scrobes 0.40–0.55 × as wide as rostral width at the same place ( Fig. 14A ). Metatibiae with long and slender mucro. Ventrites glabrous to sparsely squamose, integument predominant ( Fig. 14G ). Ventrite 2 shorter than ventrites 3 and 4 combined, suture between ventrite 1 and 2 straight ( Fig. 14G ). Sternite VIII in females with large, umbrella-shaped plate, reaching almost half of its length, with longitudinal sclerites and prominent sclerotised tip and with apodeme short and robust ( Fig. 14F ). Size 2.0– 3.3 mm ............... Phaylomerinthus Schoenherr

- Epifrons at base slightly narrower than space between eyes, between scrobes 0.70–0.80 × as wide as rostral width at the same place ( Fig. 15A ). Metatibiae amucronate. Ventrites densely squamose, integument completely covered by scales ( Fig. 15G ). Ventrite 2 longer than ventrites 3 and 4 combined, suture between ventrite 1 and 2 sinuose ( Fig. 15G ). Sternite VIII in females with small, subtriangular plate, reaching fifth to sixth of its length, without sclerites and prominent sclerotised tip and with apodeme long and slender ( Fig. 15F ). Size 1.8–2.5 mm ........................................ Lalagetes Schoenherr

Figures

FIGURE 1. Barclayanthus micros sp. nov. A—habitus, ventral view, male; B—rostrum without scales, dorsal view, male; C—rostrum without scales, lateral view, male; D—head, ventral view, male; E—ventrites, male; F—spermatheca. Scale bar: 0.25 mm (F).

FIGURE 2. Barclayanthus micros sp. nov. A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—aedeagus; E—protibia, male. Scale bars: 1 mm (A), 0.5 mm (D).

FIGURE 3. Barclayanthus cooteri sp. nov. A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—aedeagus; E—protibia, male. Scale bars: 1 mm (A), 0.5 mm (D).

FIGURE 4. Janakius sylvaticus sp. nov. A—habitus, ventral view, male; B—rostrum without scales, dorsal view, male; C— rostrum without scales, lateral view, male; D—head, ventral view, male; E—ventrites, female; F—tegmen, male; G—sternite VIII, female; H—gonocoxites; I—spermatheca. Scale bars: 0.5 mm (F, G), 0.25 mm (H, I).

FIGURE 5. Janakius sylvaticus sp. nov. A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—aedeagus; E—protibia, male. Scale bars: 1 mm (A), 0.5 mm (D).

FIGURE 7. Epistomius colonnellii Borovec & Skuhrovec, 2017. A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—protibia, male; E—tegmen, male; F—sternite VIII, female; G—ventrites, male. Scale bars: 1 mm (A), 0.5 mm (E, F).

FIGURE 8. Afromuelleria awelani Borovec & Skuhrovec, 2018. A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—protibia, male; E—tegmen, male; F—sternite VIII, female; G—ventrites, male. Scale bars: 1 mm (A), 0.5 mm (E, F).

FIGURE 9. Heisonyx sp. (undescribed species).A—habitus, dorsal view, female; B—rostrum, dorsal view, female; C—rostrum, lateral view, female; D—protibia, female; E—tegmen, male; F—sternite VIII, female; G—ventrites, female. Scale bars: 1 mm (A), 0.5 mm (E, F).

FIGURE 10. Ellimenistes albidus Fåhraeus, 1871. A—habitus, dorsal view, female; B—rostrum, dorsal view, female; C— rostrum, lateral view, female; D—protibia, female; E—tegmen, male; F—sternite VIII, female; G—ventrites, female. Scale bars: 1 mm (A), 0.5 mm (E, F).

FIGURE 11. Afrophloeus spathulatus (Boheman, 1842) (A–D, F), A. squamifer (Boheman, 1842) (E, G). A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—protibia, male; E—tegmen, male; F—sternite VIII, female; G—ventrites, male. Scale bars: 1 mm (A), 0.5 mm (E, F).

FIGURE 12. Pentatrachyphleous andersoni Borovec & Skuhrovec, 2019 (A–D, F), P. patruelis Voss, 1974 (G). A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—protibia, male; E—tegmen, male; F—sternite VIII, female; G—ventrites, male. Scale bars: 1 mm (A), 0.5 mm (E, F).

FIGURE 13. Glyptosomus costipennis Schoenherr, 1847. A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C— rostrum, lateral view, male; D—protibia, male; E—tegmen, male; F—sternite VIII, female; G—ventrites, male. Scale bars: 1 mm (A), 0.5 mm (E, F).

FIGURE 14. Phaylomerinthus cinereus Boheman, 1842 (A–D, F), P. convergens (Voss, 1962) (G). A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—protibia, male; E—tegmen, male; F—sternite VIII, female; G—ventrites, male. Scale bars: 1 mm (A), 0.5 mm (E, F).

FIGURE 15. Lalagetes subfasciatus (Boheman, 1842) (A–D, F, G), L. zitae Borovec & Skuhrovec, 2018 (E). A—habitus, dorsal view, male; B—rostrum, dorsal view, male; C—rostrum, lateral view, male; D—protibia, male; E—tegmen, male; F—sternite VIII, female; G—ventrites, male. Scale bars: 1 mm (A), 0.5 mm (E, F).