Genyocerus species

Beaver, R. A. & L. - Y, 2007, A review of the genus Genyocerus Motschulsky (Coleoptera: Curculionidae: Platypodinae), with new synonyms and keys to species, Zootaxa 1576 (1), pp. 25-56 : 31-32

Key Genyocerus species , females

[The key is designed to be used for females that still retain the brushes of hairs on the frons. Measurements of body length exclude the hair brushes and the part of the abdomen extending beyond the elytra.]

1 Antennae inserted in mid-part of frons between level of lower margin and middle of eyes ( Figs 7 , 25 ). Upper part of frons without conspicuous brushes of hairs. Pronotum usually with 6 or fewer mycangial pores on each side of midline.......................................................................................................................2

– Antennae inserted on upper part of frons above middle of eyes, usually near upper margin ( Fig. 18 ). Conspicuous brushes of hairs on upper part of frons. Pronotum usually with 8 or more mycangial pores on each side of midline......................................................................................................................................8

2 Pronotum with 2 large pores on each side of midline and a patch of small pores lateral to these. Lower part of frons with two narrow, forwardly directed, diverging pencils of hairs ( Fig. 7 ) .................................. ................................................................................................................................. G. borneensis (Browne)

– Pronotum without lateral patches of small pores beyond any larger pores. Frons without divergent pencils of hairs on lower part....................................................................................................................................3

3 Lower part of frons with a single, median brush of long hairs, downcurved at the tips. Pronotum with 3– 4 mycangial pores on each side of midline. 3.1–3.2 mm long ................................... G. plumatus (Schedl)

– Lower part of frons with 2–4 brushes of hairs. Number of mycangial pores and body length variable.....4

4 Frons with two brushes of hairs on epistomal margin, but none between or just below the antennal insertions ( Figs 24 , 31). Fifth abdominal ventrite sparsely hairy........................................................................5

– Frons with additional brushes of hairs arising in the middle of the frons between or just below the antennal insertions (Figs 29, 39). Fifth abdominal ventrite densely hairy.................................................................7

5 Antennae inserted very close to eyes. Frons with a median tubercle at its upper margin. Hair brushes extending from the midline along the epistomal margin and along the lateral margins of the frons to the level of the antennal insertions, the hairs forwardly, then upwardly directed ( Figs 24, 25 ); an impunctate triangular area on the frons above the hair brushes extending to the level of the antennal insertions. Pronotum with 0–9 mycangial pores on each side of midline ............................................ G. puer (Schedl)

– Antennae inserted about halfway between eye and midline. Frons without a median tubercle at the upper margin. Hair brushes not extending to level of antennal insertions. Pronotum with 0–3 mycangial pores on each side of midline.................................................................................................................................6

6 Epistomal hair brushes arising from a roughly oval convexity on each side, forming two dense tufts separated by a short median gap. Hairs in upper part of brush downcurved towards tips, those in lower part of brush with tips curved towards midline. Pronotum with 0–3 mycangial pores on each side of midline ...... ................................................................................................................................. G. pendleburyi (Schedl)

− Epistomal hair brushes arise from a narrower, more elongate area on each side, the brushes less dense and continuing to the midline without a median gap (Fig. 31). Hairs of epistomal brushes all inwardly curved towards the midline. Pronotum with a single mycangial pore on each side of midline ................................ ........................................................................................................................... G. quadrispinosus (Schedl)

7 Larger species, 2.7–3.4 mm long. Pronotum with 4–6 mycangial pores on each side of midline. Fifth ventrite with a median longitudinal groove. Epistomal hair brushes long, with upwardly and inwardly curved hairs crossing in the midline a little below the middle of the frons. Upper frontal hair brushes with the hairs forwardly directed and divergent, but curved ventrally and towards the midline in the apical third over the apical part of the epistomal brushes ( Figs 28 , 29). Lower third of frons exposed between the hair brushes .................................................................................................................... G. quadriporus (Schedl)

– Smaller species, 2.2–2.4 mm long. Pronotum with 2–3 mycangial pores on each side of midline. Fifth ventrite without a median longitudinal groove. Epistomal hair brushes much shorter, not reaching middle of frons. Upper brushes with the hairs forwardly directed and divergent, but curved ventrally and towards the midline in the apical third over the apical part of the epistomal brushes, relatively larger, and extending lower on the frons, the hairs almost concealing the lower third ( Figs 38, 39 ) ........ G. tenellus (Schedl)

8 Pronotum usually with 2 large pores on each side of midline (occasionally absent) and a patch of smaller pores laterally to these. Upper brush of frontal hairs divided into two tufts, the insertions of the inner one extending across the frons to the midline, both tufts directed forward, the tips of the longer hairs incurved towards the middle of the frons ( Fig. 10 ). Small species 2.1–2.2 mm long ..................... G. exilis (Schedl)

− Pronotum without a patch of smaller pores in addition to large pores. Mostly larger species, at least 2.6 mm long. Upper hair brushes usually separated by a broad gap, not extending to midline (the gap narrow in G. frontalis , which is 3.8–4.0 mm long)...................................................................................................9

9 Pronotum with from 30 to more than 60 small mycangial pores on each side of midline. Larger species, at least 4.5 mm long........................................................................................................................................10

− Pronotum with no more than 30 mycangial pores on each side of midline. Smaller species, not more than 4.0 mm long................................................................................................................................................11

10 Mycangial pores on pronotum larger and fewer, with about 50 pores on each side of midline (Fig. 20). Papua New Guinea....................................................................................................... G. papuanus Roberts

− Mycangial pores on pronotum smaller and more numerous, with 60 or more on each side of midline ( Fig. 16 ). Southeast Asia, Philippines.............................................................................. G. multiporus (Schedl)

11 Smaller species, 2.6–3.2 mm long..............................................................................................................12

– Larger species, 3.6–4.0 mm long................................................................................................................13

12 Pronotum with 4–10 mycangial pores on each side of midline. Upper hair brushes arising from an approximately oval area on upper part of frons just below antennal insertions, each brush divided into two groups of hairs, the larger inner group shorter and directed forward, the smaller, outer group longer, curved ventrally and crossing the midline .................. G. albipennis Motschulsky or G. diaphanus (Schedl) [females of these two species are not distinguishable]

– Pronotum with 20–28 mycangial pores on each side. Insertions of upper hair brushes arising from a narrow band extending from antennal insertions towards epistoma, the longer hairs directed ventrad, not incurved towards midline, the lower hairs much shorter, directed forward ( Figs 33, 34 ).............................. ....................................................................................................................................... G. serratus (Schedl)

13 Insertions of hair brushes on upper part of frons extending dorsally well above antennal insertions and nearly meeting medially just below vertex, the majority of hairs directed forward, downcurved at tips, a few of the lowest hairs longer and incurved towards midline (Figs 13, 14). Epistomal brushes divided into two parts on each side, the long hairs upcurved below those of the upper brushes, almost reaching vertex. Pronotum with 9–12 mycangial pores on each side. Last ventrite with a median tubercle in apical half.... ............................................................................................................................... G. frontalis (Strohmeyer)

– Insertions of upper hair brushes not extending well above antennal insertions, widely separated medially. Epistomal brushes subdivided or not. Pronotum with 10–22 mycangial pores on each side. Last ventrite without a median tubercle...........................................................................................................................14

14 Epistomal brushes clearly divided into two adjacent parts on each side, the long hairs of each part slightly diverging in the midpart, usually extending to the vertex, partly covering the upper part of the frons, the insertions very narrowly separated medially; upper brushes parallel or weakly convergent (Figs 35, 36). Pronotum with 10–13 mycangial pores on either side of midline. 3.6–3.8 mm long .. G. talurae (Stebbing)

– Epistomal brushes broad, not divided into two parts on each side, the hairs not divergent, curved upwards to reach a little beyond the middle of the frons, leaving the upper part uncovered, the insertions more widely separated medially, the gap with a sparse line of forwardly directed hairs on the lower part of the frons; upper brushes divergent ( Figs 2–4 ). Pronotum with 14–22 mycangial pores on each side of midline. 3.8–4.0 mm long ................................................................................................... G. biporus (Schedl)

Figures

PLATE 1. FIGURE 1. Genyocerus biporus (Schedl) dorsal view of male. FIGURE 2. Genyocerus biporus (Schedl) dorsal view of female. FIGURE 3. Genyocerus biporus (Schedl) frontal view of female head. FIGURE 4. Genyocerus biporus (Schedl) lateral view of male head.

PLATE 2. FIGURE 5. Genyocerus borneensis (Browne) dorsal view of male. FIGURE 6. Genyocerus borneensis (Browne) lateral view of male elytra. FIGURE 7. Genyocerus borneensis (Browne) fronto–dorsal view of female head.

PLATE 3. FIGURE 8. Genyocerus diaphanus (Schedl) dorsal view of male. FIGURE 9. Genyocerus exilis (Schedl) lateral view of male elytra. FIGURE 10. Genyocerus exilis (Schedl) lateral view of female head.

PLATE 5. FIGURE 15. Genyocerus multiporus (Schedl) dorsal view of male. FIGURE 16. Genyocerus multiporus (Schedl) dorsal view of head and pronotum of female. FIGURE 17. Genyocerus multiporus (Schedl) lateral view of female head. FIGURE 18. Genyocerus multiporus (Schedl) frontal view of female head.

PLATE 7. FIGURE 23. Genyocerus puer (Schedl) dorsal view of male. FIGURE 24. Genyocerus puer (Schedl) dorsal view of female. FIGURE 25. Genyocerus puer (Schedl) lateral view of head of female.

PLATE 8. FIGURE 26. Genyocerus quadriporus (Schedl) dorsal view of male elytra. FIGURE 27. Genyocerus quadriporus (Schedl) lateral view of male elytra. FIGURE 28. Genyocerus quadriporus (Schedl) dorsal view of female.

PLATE 10. FIGURE 32. Genyocerus serratus (Schedl) dorsal view of male. FIGURE 33. Genyocerus serratus (Schedl) dorsal view of head and pronotum of female. FIGURE 34. Genyocerus serratus (Schedl) lateral view of head of female.

PLATE 12. FIGURE 37. Genyocerus tenellus (Schedl) dorsal view of male. FIGURE 38. Genyocerus tenellus (Schedl) dorsal view of female. FIGURE 39. Genyocerus tenellus (Schedl) lateral view of female head.