Ischnopoda Stephens, 1835, 1837

PA – NIK, GRZEGORZ, 2006, Taxonomy and phylogeny of the World species of the genus Ischnopoda Stephens, 1837 (Coleoptera, Staphylinidae: Aleocharinae), Zootaxa 1179 (1), pp. 1-96 : 12-17

Genus Ischnopoda Stephens, 1835 ( Figs. 2–15)

Ischnopoda Stephens, 1835: 430 .

Type species: Staphylinus leucopus Marsham, 1802: 506 (fixed by the International Commission of Zoological Nomenclature ( ICZN 1961)).

Ischnopoda: Thomson, 1859:35 (as valid genus).

Ischnopoda: Thomson, 1861:4 (as valid genus).

Cathusya Mulsant & Rey, 1875: 383 (as subgenus of Tachyusa ) syn. n.

Type species: Tachyusa scitula Erichson, 1837: 308 (by monotypy).

Rechota Sharp, 1883: 228 , syn. n.

Type species: Rechota impressa Sharp, 1883: 229 (by monotypy).

Tachyusa (Ischnopoda) : Ganglbauer, 1895: 244 (as valid subgenus of Tachyusa ).

Amanota Casey, 1906: 189 , syn. n.

Type species: Amanota capensis Casey, 1906: 190 (by monotypy).

Ischnopoda: Reitter, 1909: 72 (as valid genus).

Calischnopoda Reitter, 1909: 73 (as subgenus of Ischnopoda ), syn. n.

Type species: Drusilla exarata Mannerheim, 1830: 85 (by monotypy).

Tachyusa (Ischnopoda) : Bernhauer & Scheerpeltz, 1926: 583 (as valid subgenus of Tachyusa ). Pischnopoda Tottenham, 1939: 226 .

Type species: Staphylinus leucopus Marsham, 1802: 506 (junior objective synonym of Ischnopoda Stephens, 1835 (fixed by the International Commission of Zoological Nomenclature ( ICZN 1961)).

Tachyusa (Ischnopoda) : Lohse, 1974: 70 (as valid subgenus of Tachyusa ).

Ischnopoda: Lucht & Klausnitzer, 1998: 176 (as valid genus).

Diagnosis. Ischnopoda can be recognized by the combination of the following characters: body parallel­sided; ligula ( Fig. 5 ) narrow and short, bifid to about middle, lobes divergent apically; pronotal hypomera fully visible in lateral view; lateral sides of elytra weakly arcuate, widest in posterior 1/3, postero­lateral angles very slightly sinuate; abdomen slightly constricted at base; tergal basal transverse impressions coarsely and densely punctuate; tarsal formula 4­5­5; metatarsus long, exceeding 4/5 length of metatibia; basal segment of metatarsus at least subequal in length to following two tarsal segments combined.

Redescription. Body. Small to medium sized, length 2.1–4.5 mm. Body parallelsided, moderately to strongly convex, dull to glossy ( Fig. 2).

Head. Circular in outline, temples parallel­sided or arcuately narrowed to hind angles; eyes protruding from lateral contours of head, genae not margined. Antennae moderately long, distinctly increased in width apically.

Mouthparts. Maxillary palpi 4­segmented ( Fig. 3 ), palpomere 1 very short, palpomere 2 elongate, slightly widened apically, palpomere 3 slightly longer than 2, palpomere 4 short, subuliform. Galea long and slender, subequal in length to lacinia ( Fig. 3 ). Labrum ( Fig. 4 ) transverse, moderately arcuately emarginate apically and with characteristic arrangement of setae. Labial palpi 3­segmented ( Fig. 5 ), palpomere 1 elongate, palpomere 2 shorter and narrower than 1, palpomere 3 narrower and much longer than 2. Ligula ( Fig. 5 ) narrow and short, bifid to about middle, lobes divergent apically. Mentum trapezoidal ( Fig. 6 ), with five long setae on each side, apical margin slightly concave, anterior angles rounded. Mandibles curved towards apex, right mandible ( Fig. 7 ) with distinct molar tooth at middle of inner margin, faintly serrate in dorsal molar region.

Thorax. Pronotum subquadrate to transverse, moderately to strongly convex, dull to glossy, widest in apical third, lateral sides narrowed in straight line or concavely to hind angles. Pubescence at midline of one of three types: directed entirely anteriorly, directed entirely posteriorly or directed posteriorly in apical half and anteriorly in basal half; pubescence at lateral parts directed arcuately laterally or arcuately inward ( Fig. 8 ). Hypomera fully visible in lateral view. Mesocoxae varie from narrowly to widely separated ( Figs. 10–15 ). Mesosternal process varies from narrowly triangular, extending to 1/2 length of mesocoxa and separated from metasternal process by short and narrow isthmus ( Fig. 10 ), throughout intermediate states ( Figs. 11–14 ) to broad and short, extending to 1/3 length of mesocoxa and separated from metasternal process by short transverse isthmus ( Fig. 15 ). Mesocoxal cavities not or margined posteriorly by fine bead.

Elytra. Slightly wider than pronotum, lateral sides weakly arcuate, widest in posterior 1/3, postero­lateral angles very slightly sinuate ( Fig. 9 ).

Legs. Tarsal formula 4­5­5. Metatarsus long, exceeding 4/5 length of metatibia; basal segment of metatarsus at least subequal in length to following two tarsal segments combined.

Abdomen. Slightly constricted at base, widest at level of tergites 5 and 6, tergites 3–5 distinctly transversely impressed at base, tergites 5 and 7 subequal in length, sternites 3–5 slightly transversely impressed at base, tergal and sternal impressions coarsely and densely punctuate.

Figures

FIGURES 3–7. Ischnopoda sp.: 3—maxilla, 4—labrum, 5—labium, 6—mentum, 7—mandible.

FIGURES 8–9. Ischnopoda sp.: 8—pronotal pubescence, 9—shape of elytron.

FIGURES 10–15. Ischnopoda sp.: variability of mesosternum and metasternum.