Tanymecini, Lacordaire, 1863

Cortés-Hernández, Kevin A. & Morrone, Juan J., 2019, A key to the Mexican genera of Tanymecini (Coleoptera: Curculionidae), Zootaxa 4615 (1), pp. 46-56 : 47-48

Key to the Mexican genera of Tanymecini

1 Metatibial apex simple ( figures 1 and 2 )................................................................... 2

1’ Metatibial apex with false or true corbels ( figures 3–6 )........................................................ 6

2 Anterior margin of abdominal ventrites 3–5 flat, not sulcate ( figure 7 ); front legs generally greatly larger than middle and hind legs................................................................................................ 3

2’ Anterior margin of abdominal ventrites 3–5 sulcate across almost entire width of abdomen or medially only (except Isodacrys minutum ) ( figure 8 ); front legs from not at all enlarged to slightly larger than middle and hind legs..................... 4

3 Mandibles on lateral and ventral surface with scales; front coxae contiguous or narrowly separated.......... Hadromeropsis

3’ Mandibles without scales; front coxae distinctly separated................................ Pandeleteius (Pandeleteius)

4 Tarsal claws connate............................................................................ Isodrusus

4’ Tarsal claws free...................................................................................... 5

5 Humeri well developed; with postocular vibrissae well developed or reduced to 1–3 hairs.................. Pandeleteinus

5’ Humeri rounded to partially developed ( figure 15 ); with or without postocular vibrissae...................... Isodacrys

6 Metatibial apex with false corbels; humeri well-developed, oblique or quadrate; tarsi 1–3 on ventral surface with pads of setiform setae........................................................................................... 7

6’ Metatibial apex with true corbels; humeri rounded; tarsi 1–3 on ventral surface with stout, spiniform setae instead of pads of setiform setae; apex of hind tibae bearing conical to lameliform bristles, shorter to subequal in length to the surrounding setae.......................................................................................... Minyomerus

7 Dorsal surface of rostrum apicad of antennal insertion elevated in a platform consisting of an apical glabrous portion followed by a squamose portion, with posterior margin ending in a transverse inter-antennal groove; front legs distinctly larger than middle and hind legs; front coxae separated; hind tibia without straight comb of setae on outer edge.................... 8

7’ Dorsal surface of rostrum apicad of antennal insertion not elevated in a platform; front legs not larger than middle and hind legs; front coxae contiguous; hind tibia with straight comb of setae on outer edge, comb at least as long as width of tibia at apex............................................................................................. Tanymecus

8 Rostrum with apical glabrous portion of platform not separated from the squamose portion by a carina ( figure 9 ); vibrissae present....................................................................................... Airosimus

8’ Rostrum with apical glabrous portion of platform separated from the squamose portion by a carina ( figure 10 ); ocular vibrissae absent........................................................................ Pandeleteius (Exmenetypus)

Figures

FIGURES 1–6. Types of metatibial apex in Tanymecini. 1. Pandeleteinus subcancer, apex simple, right tibia, without tarsi. 2. P. subcancer, left tibia, with tarsi. 3. Tanymecus confusus, apex with false corbel, right tibia, without tarsi. 4. T. confusus, left tibia, with tarsi. 5. Minyomerus laticeps, apex with true corbel, right tibia, without tarsi. 6. M. laticeps, left tibia, with tarsi.

FIGURES 7–10. Modifications in the ventrites. 7. Pandeleteius fasciatus ventrites, anterior margin of ventrites 3–5 flat, not sulcate. 8. Pandeleteinus subcancer ventrites, anterior margin of ventrites 3–5 sulcate almost by entire width of abdomen. Figures 9–10. Dorsal surface of rostrum. 9. Airosimus callifer. 10. Pandeleteius (Exmenetypus) championi.

FIGURES 11–16. Species of Mexican Tanymecini. 11. Airosimus callifer, dorsal habitus. 12. A. callifer, lateral habitus. 13. Hadromeropsis brevicoma, dorsal habitus. 14. H. brevicoma, lateral habitus. 15. Isodacrys mexicanum, dorsal habitus. 16. I. mexicanum, lateral habitus.