Agrodes Nordmann, 1837

Asiain, Julieta, Márquez, Juan & Morrone, Juan J., 2007, Phylogenetic systematics of the genera Plochionocerus Dejean and Agrodes Nordmann (Coleoptera: Staphylinidae: Xantholinini), Zootaxa 1584, pp. 1-53 : 41-46

Agrodes Nordmann, 1837 stat . rev.

Agrodes Nordmann, 1837: 161 (type species: A. elegans Nordmann, 1837 , by monotypy); Erichson, 1847: 88; Lacordaire, 1854: 66; Gemminger & Harold, 1868: 599 (synonym of Sterculia ); Sharp, 1876: 192; Bernhauer & Schubert, 1914: 314 (subgenus of Sterculia ); Blackwelder, 1952: 42 (subgenus of Plochionocerus ); Newton, 1995: 51 (request to the ICZN to place Agrodes on the Official List of Generic Names in Zoology); ICZN, 1996: 215 (Official List of Generic Names in Zoology).

Diagnosis. Body bright metallic; head conspicuously oblong (length/width: 1.54–2.00); lateral margins of the head contiguous dorsally and ventrally, lacking lateroventral furrows; ventral surface of the head with very dense, not expanded, umbilicate punctures (> 30 on each half of the head) distributed homogeneously; anterior margin of labrum with two pairs of small, lateral teeth and a pair of central, longer teeth ( Fig. 37 ); mandibles almost as long as half of the head length; apical labial palpomere elongate; upper line of the pronotal hypomeron completely developed ( A. conicicollis ) or absent ( A. elegans ), slightly directed downwards in anterior third, but clearly distinct from lower line; pronotal hypomeron with fine, scarce setae in all area or in posterior 2/3; posterior margin of the elytra lacking notch; and internal margin of the tibiae with brush of dense and light setae covering the basal half or basal 2/3 of the tibiae.

Redescription. Total length 17.5–23.8 mm. Body metallic blue, green or violet.

Head. Elongate (length/width: 1.54–2.00), narrow posteriorly, dorsally with dense, umbilicate punctures ( Fig. 3 ), ventral surface with very dense, not expanded, umbilicate punctures (> 30 in each half of head) distributed homogeneously ( Fig. 67 ); lateral margins of head without lateroventral furrows ( Fig. 10 ); antennae with basal antennomere longer than antennomeres 2+3 combined, second antennomere shorter than third, remaining antennomeres shorter than second, apical antennomere shorter than antennomeres 9+10 combined ( Figs. 22, 23 ); anterior margin of labrum with two pairs of small, lateral teeth and a pair of bigger, central teeth ( Fig. 37 ); mandibles acute, almost as long as half of head length, with two teeth on left mandible and one on right, with channel on external basal half ( Figs. 38, 39 ); first maxillary palpomere shorter than remaining articles, second longest, third almost as long as apical palpomere and slightly widened toward apex, apical palpomere elongate-conical ( Fig. 42 ); first labial palpomere shorter than palpomeres 2+3, second almost as long as apical or slightly longer and slightly widened toward apex, apical palpomere elongate ( Fig. 42 ). Neck narrow, with anterior corners obtuse ( Fig. 67 ).

Thorax. Pronotum smooth; with fine, dispersed setiferous punctures, central longitudinal area without punctures ( Fig. 3 ); lateral margins of posterior half slightly sinuate; posterior part of pronotum with slightly visible, depressed area in each half; upper line of pronotal hypomeron completely developed, except in anterior third ( A. conicicollis , Fig. 65 ) or absent ( A. elegans , Fig. 66 ), slightly directed downwards in anterior third, but clearly distinct from lower line; pronotal hypomeron with fine, scarce setae on whole area or in posterior 2/3 ( Figs. 65, 66 ). Scutellum with scarce punctures. Elytra almost as long as pronotum; with dense, setiferous punctures; posterior margin without notch ( Figs. 3 , 58 ). Prosternum slightly oblong (length/width ratio 1.04–1.20; Fig. 67 ), with fine, dispersed setae ( Fig. 67 ). Mesoventrite short and wide, surface smooth and with scarce setiferous punctures on posterior margin. Metaventrite biggest, with its surface smooth and with few setiferous punctures.

Legs. Long and slender; femora with dispersed setae on the internal and external faces; internal face of tibiae with brush of dense white setae in the basal half or 2/3 ( Fig. 61 ), with apical spines, of which the internal one is longest; first and second tarsomeres almost equal in length, longer than third and fourth, third longer than fourth, and fifth longest (almost as tarsomeres 2+3 combined).

Abdomen. Surface with smooth and setiferous punctures as dense or slightly less dense than those on elytra; fifth and sixth visible abdominal segments conspicuously narrow than previous segments; male genital sternite elongate, asymmetrical and acute toward apex, with setae in anterior part, wider than genital tergite. Aedeagus. Variable in shape ( Figs. 75, 76 ).

Comparative comments. Agrodes was established by Nordmann (1837), who distinguished it from the species then placed in Plochionocerus . Some authors ( Erichson 1839, Laporte 1840, Gemminger & Harold 1868, Blackwelder 1944), however, synonymized it with Sterculia , whereas others ( Erichson 1847, Lacordaire 1854) considered it valid, treating Sterculia and Araeocnemus as synonyms of Agrodes or as its subgenera ( Bernhauer & Schubert, 1914). Sharp (1876, 1885) was the first author to distinguish Agrodes from Sterculia (now Plochionocerus ) and Renda (named by him as Plochionocerus ) and provided characters (such as the elongate head and development of the prosternum) that have been important for our decision to consider Agrodes a distinct genus.

Figures

FIGURES 32 – 39. Labrum: 32, Homalolinus flavipennis; 33, Renda flagellicornis; 34, Plochionocerus marquezi; 35, P. simplicicollis; 36, P. puncticeps; 37, Agrodes elegans. Mandibles: 38, Agrodes conicicollis; 39, A. elegans.

FIGURES 1 – 6. Habitus, dorsal view: 1, Plochionocerus simplicicollis; 2, P. s p l e n d e n s; 3, Agrodes elegans; 4, Renda fimetaria; 5, Philonthus testaceipennis; 6, Homalolinus flavipennis. Scale bar 3 mm.

FIGURES 67 – 68. Ventral view of anterior part of body: 67, Agrodes conicicollis; 68, Plochionocerus splendens.

FIGURES 9 – 16. Lateral view of head: 9, Philonthus testaceipennis; 10, Agrodes elegans; 11, Plochionocerus discedens; 12, P. gracilis; 13, P. humeralis; 14, P. m a rq u e z i; 15, P. simplicicollis; 16, Renda flagellicornis.

FIGURES 20 – 31. Antennae: 20, Philonthus testaceipennis; 21, Renda flagellicornis; 22, Agrodes conicicollis; 23, A. elegans; 24, Plochionocerus gracilis; 25, P. humeralis; 26, P. i g n e u s; 27, P. m a rq u e z i; 28, P. puncticeps; 29, P. re t i c u - laris; 30, P. s p l e n d e n s; 31, P. transversalis.

FIGURES 40 – 47. Maxillary (a) and labial (b) palpi: 40, Philonthus testaceipennis; 41, Renda flagellicornis; 42, Agrodes elegans; 43, Plochionocerus impressipennis; 44, P. gracilis; 45, P. m a rq u e z i; 46, P. simplicicollis; 47, P. puncticeps.

FIGURES 63 – 66. Lateral view of pronotal hypomeron: 63, Plochionocerus simplicicollis; 64, Renda spp.; 65, Agrodes conicicollis; 66, A. elegans.

FIGURES 54 – 62. Pronotum: 54, Philonthus testaceipennis; 55, Renda flagellicornis; 56, Plochionocerus simplicicollis; 57, P. reticularis. Elytra: 58, Agrodes spp.; 59, Plochionocerus spp. Midleg: 60, Philonthus testaceipennis; 61, Agrodes spp.; 62, Plochionocerus spp.

FIGURES 69 – 78. Ventral (left) and lateral (right) view of aedeagus: 69, Philonthus testaceipennis; 70, Homalolinus flavipennis; 71, Thyreocephalus puncticeps; 72, Renda fimetaria; 73, R. flagellicornis; 74, R. leprieuri; 75, Agrodes conicicollis; 76, A. elegans; 77, Plochionocerus ashei; 78, P. discedens. Scale bar 1 mm.