Paederidus ruficollis

Staniec, Bernard, Pietrykowska-Tudruj, Ewa & Sałapa, Dorota, 2011, Description of the egg and larva of Paederidus Mulsant & Rey, 1878 (Coleoptera, Staphylinidae, Paederinae) based on the two European species, Zootaxa 2888, pp. 39-56 : 41-51

P. ruficollis

Egg ( Figs 1, 1 A). Length: 0.70–0.75 (0.72), width: 0.63–0.66 (0.61). Macroscopic ( Fig. 1 ): color dark beige, shape somewhat oval, surface slightly rough and matt. Microscopic ( Fig. 1 A): microsculpture consisting of dense, evenly distributed pits.

Mature larva (L2). Body length: 5.17–7.32 (6.10); head width: 0.74–0.83 (0.78); head length: 0.68–0.82 (0.74); prothorax width: 0.86–1.00 (0.90). Colouration, dorsal side: head, antennae and mouth part orange yellow, pronotum black brown, mesonotum almost colorless, metanotum brown, leg light ivory, abdominal tergites–I–VII brown, VIII and IX black brown, X light ivory, urogomphi–base dark brown, remaining part light ivory, macro- and microsetae black; ventral side: pronotum brown, mesonotum colourless, metanotum and abdominal sternites I– VII ochre yellow, abdominal sternites VIII and IX brown.

Body elongate, central part of head with large, oval, brown spot, width of spot distinctly larger than distance between spot and base of head, prothorax distinctly wider than head, almost twice as longe as and slightly narrower than mesothorax, meso- and metathorax almost equal in width and length, legs relatively long and slender, abdomen slightly and gradually widened to segment IV and then narrowed to the terminal segment of the body ( Fig. 2 ). All macro- and microsetae simple ( Figs 4–6 ).

Head almost as long as wide, side margins slightly rounded, narrowing from the stemata area to the base; dorsal ecdysial suture bifurcate almost at half the head length (Fig. 7, Des). Epicranial part (E) (Fig. 7): with 11 pairs of setae (Ed1–3, El1–5, Em1–3), 3 pairs of pores (Ep1–3) and pair of hair-like trichobothria (Trb, Fig. 8B); posterior part (Fig. 7, P) with 5 pairs of microsetae (P1–5); microstructure clearly visible only on brown spot area ( Figs 2 , 7A). Nasale (Na) (Figs 7, 15): with 10 pairs of setae, 2 pairs of frontal campaniform sensilla (Fc1–2) and pair of glandular pits (Gp) posterolaterally; anterior margin with 4 teeth 2(Pmt, Lt) and four pairs of peg setae (Ps1–4), medial region (Mr) slightly convex, paramedian tooth about 1.4 times as long as lateral tooth (Lt) (without peg seta), each paramedian tooth with large olfactory organ ventrally (Og) (Figs 16, 20). Each side of head with six oval or circular, subequal stemmata in clusters (Figs 8, 8A); lateral parts (Fig. 8) with 13 pairs of setae (Ps1–4, T1– 6, L1–3) and 2 pairs pores (Lp, Tpr). Ventral side of head with 4 pairs of setae (V1, Vl1–3) and 4 pairs of ventral pores (Vp1–4). Apotome (Ap) (Figs 9, 9A) partially formed, ventral ecdysial suture ending in vicinity of tentorial pit (Tp). Mandibles (Fig. 10): long and moderately broad; inner margin uniformly serrate for over half of its length; with 1 long seta (L2) at outer margin, 1 large sensillum dorsally (Dsm) and 1 large sensillum dorsolaterally (Lsm); 3 sensilla located near apex (Fig. 10A); base with group of numerous microtrichia (Bm) dorsobasally (Figs 10, 10B). Antenna (Figs 13, 14) 4-segmented, length ratio of segments I–IV 1.0:2.7:3.3:2.0. segment I 1.3 x as wide at the base as long; segment II 2.9 x as long as wide, with 1 seta dorsoapically and 4 pores (2 dorsoapically, 1 laterally, 1 ventrobasally); segment III 3.6 x as long as wide in the widest place, with 3 macrosetae (1 dorsolateral, 1 lateroapical, 1 lateral), 3 solenidia (So) (2 long, 1 short) and 1 finger-shaped sensory appendage (Sa) 4.8 x as long as wide; segment IV club-shaped, gradually widened apically, about 3.3 x as long as maximum width, about 2.1 x as long as sensory appendage of segment III, with 3 long setae and 4 solenidia (So) apically (2 short, equal in length; 2 long, equal in length). Epipharynx (Fig. 20): with 2 transverse rows of cuticular processes: the first one (Acp) with about one hundred, long cuticular processes along anterior margin of buccal cavity (Bc), row incomplete with a tuft of cuticular processes setae centrally, the second one (Pcp) with about a hundred short cuticular processes along posterior margin of buccal cavity; pharynx with 20–30 pharyngeal pores (Pp) and a pair of sensilla (Sm). Maxilla (Figs 22, 23): length ratio of cardo (Cd) and stipes (St) 1:1.7; cardo quadrangular as long as wide with 1 seta ventrally; stipes narrowed anteriorly, 1.4 x as long as maximum width, with 7 setae (1 dorsal, 3 anterodorsal, 1 ventral, 2 short ventrolateral), 1 ventrobasal trichobothrium (Trb), longitudinal series of 25–30 microtrichia dorsally (Fig. 22A) and 1 pore ventrally; mala (Ma) relatively tiny, finger-shaped (Figs 22, 23), about 3 x as long as wide, with 4 setae apically (1 long, 3 short) and 1 pore ventrobasally, long apical seta distinctly longer than mala, segment I of maxillary palp 2.2 x as long as mala. Palpifer (Pf) (Fig. 23) crescent-shaped with 1 long seta and 1 pore. Maxillary palp (Mp) (Fig. 22): 3-segmented, length ratio of segments I–III: 1.0:1.6:2.4 respectively; segment I 1.6 x as long as wide, clearly widened apically with two pores ventroapically; segment II 2 x as long as wide with 2 setae [code 1, 2 (1–lateroapically, 2–laterobasally)] and 1 pore apicodorsally; segment III gradually narrowed to apex, 4.1 x as long as maximum width, with sensory appendage (Sa) laterobasally and ring of wrinkled cuticula (Rw) at two thirds of segment length from the base (Fig. 22), width of Rw to length of segment III ratio: 1:6–8, segment III 3.7 x as long as sensory appendage (Sa). Hypopharynx (Fig. 25): dorsal side of labium membranous and densely pubescent with the exception of posterior and lateral parts; at the base with row of cuticular processes, long laterally and short medially. Labium (Fig. 28): ventral side of prementum (Pmnt) sclerotized, trapeziform with 4 setae (2 short, 2 long) and two pores apically; ligula (Lg) conical, 1.8 x as long as wide at the base, about as long and twice as wide basally as segment I of labial palp, with numerous ventral microtrichia (Vmt), ligula and prementum separated by sclerotized strip (Ss). Labial palps (Lp) 2-segmented (Figs 25, 28); segment I 1.3 x as long as II; segment I about 3 x as long as wide with 1 pore ventrally; segment II about 5 x as long as wide basally with 1 pore mediolaterally and ring of wrinkled cuticula (Rw) at about half length of segment II, width of Rw to length of segment II ratio: 1:3.0–3.3.

Thorax: pro-, meso-, and metanotum with mid-longitudinal ecdysial line. Pronotum (Fig. 29): 1.2–1.3 x as wide as long, moderately rounded on sides, widest at half of its length, with 23 pairs of setae (A1–3, Da1–2, Db1– 3, L1–11, P1–4), pair of pores Ap1 and a pair of tergal glands (Tg). Mesonotum almost equal in width and one and a half as long as metanotum, with similar chaetotaxy. Mesonotum (Fig. 29): almost twice as wide as long, distinctly rounded on sides, widest at one third of its length from the base, with transverse carina anteriorly and 16 pairs of setae (A1–4, Da2, Db2, L4–L7, L10, L11, P1–4). Microstructure of discal region of pro-, meso- and metanotum as in Fig. 29B. Prosternal region (Fig. 32): presternum (Pr) strip shaped and moderately curved, uniform (not divided), but trace of medial fusion clearly visible (Fig. 32); with 5 pairs of setae (2 long, 3 short); sternum divided, sternites widely separated, each with 6 short setae, membrane between sternites without setae. Mesosternal region (Fig. 32) with 2 pairs of short setae, each growing from a weakly sclerotized, small plate. Metasternal region (Fig. 32) with a pair of short setae. Fore leg (Fig. 33): coxa (Cx) moderately elongate about 2.8 x as long as maximum width, with 23 setae (Ad1–3, Al1–7, Av1–2, D1–3, Pl1–3, Pd1–3, V1–2), dorsal region of coxa with numerous spine-shaped cuticular processes (Cp) (Fig. 33A); trochanter ( Tr) divided, with 8 setae (Ad1, Al1, Av1–2, Pl1, Pv1, V1–2) and a few pores; femur (Fe) elongated and slender, 5.4 x as long as wide in the widest place, with 27 setae (Ad1–4, Al1–3, Av1–3, D1–5, Pd1, Pl1–4, Pv1–5, V1–2) and 2 pores (Plp, Alp), microstructure as in Fig. 33B; tibia (Tb) elongated and extremely slender, 8.5 x as long as maximum width, with 15 setae (Ad1–3, Al1–3, Av1–2, D1, Pd1–2, Pl1, Pv1–3) and 4 pores; tarsungulus (Ts) moderately curved (Fig. 34), about 4.4 x as long as basal width, with 2 spine-shaped setae (Al1, Pl1), about 2.1 x as long as seta Al1. Length ratio of coxa, trochanter, femur, tibia and tarsungulus: 5.5:2.0:5.4:4.4:1 respectively. The region between pro- and mesothorax with a large, elliptical spiracles (Fig. 29A); 1 seta dorsal to spiracle.

Abdomen: tergites and sternites of abdominal segments I–VII divided by weakly sclerotized, longitudinal membranes ( Figs 2 , 38, 41). Segment I: tergite with transverse carina and 12 setae (A2–3, Da2, Db2, L1–2, L4–5, P1–4) (Fig. 38); well developed paratergite (Pt) and rudimentary parasternite (Ps) on each side, with 4 setae (3 short) and 1 short seta respectively (Fig. 39); sternite rudimentary, with 4 short setae (Fig. 40). Segments II–VIII: tergite (Fig. 38) with 11 pairs of setae (A2–3, Da2, Db2, L2, 4–5, P1–4); well developed oval or elongate (segment VIII) paratergite (Pt) and parasternite (Ps) on each side, with 5 and 4 setae respectively (Figs 39, 43); sternite well developed, with 9 pairs of setae on sternite II (A3, Da2, Db2, L5, P1–3 + 2 short setae not coded), 10 pairs of setae on sternites III–VII (A3, Da2, Db2, L5, P1–3 + 3 short setae not coded), 9 pairs of setae on sternite VIII (A3, Db2, L5, P1–3 + 3 short setae not coded). Abdominal segments I–VIII, each with a pair of circular spiracles (Sp) located between tergites and paratergites (Figs 39, 43). Segment IX (Figs 42, 44, 45): without paratergite and parasternite (Fig. 45), tergite with 5 pairs of setae (2 long and 3 short) and a pair of pores (Figs 44, 45), sternite with 4 pairs of setae (2 long, 2 short) (Fig. 42). Urogomphus (Ug): 2-segmented, elongate, relatively very long; segment I moderately slender, about 7 x as long as wide at the base, with 9 long setae (D1, L1–2, Ld2–3, M1, V1–3) and a short seta (Ld1), partly strongly sclerotized, dark brown cuticule with reticulate microstructure forming 4 rings separated by regions of light and weakly sclerotized cuticule (Figs 44–44B); segment II very slender, about 15 x as long as wide, distinctly narrower than segment I, with 1 long apical seta and 1 moderately long subapical seta (Figs 44, 45); length ratio of segments I: II: apical seta of urogomphus: 2.4:1:1.4; 6.7–7.1 x as long (without apical seta) as pygopod (segment X). Segment X: about half as long and less than half as wide as segment IX, with 6 pair of setae (4 moderately long, 2 short) and 3 pairs of pores (Figs 44, 45).

First larval instar (L1). Body length: 3.24–4.84 (4.02); head width: 0.57–0.62 (0.60); head length: 0.43–0.67 (0.60); prothorax width: 0.43–0.75 (0.60). Colouration, dorsal side: head, antennae and mouth part yellow, pronotum black brown, mesonotum almost colorless, metanotum and abdominal tergites I–VIII light brown, abdominal tergite IX dark brown, leg and abdominal tergite X yellow, urogomphi–base dark brown, remaining part yellow, macro and microsetae almost colourless; ventral side: pronotum, mesonotum, metanotum and abdominal sternites I–IV colourless, abdominal sternites V–VIII yellowish brown, IX brown.

Head. Mandibles: base with bunch of a few microtrichia (Bm) dorsolaterally (Fig. 10C). Antenna (Figs 11, 12) shorter and stouter than in L 2: length ratio of segments I–IV: 1.0:2.0:3.4:2.6 respectively; segment I 1.8 x as wide at the base as long; segment II 1.6 x as long as wide, with 1 seta dorsoapically; segment III 2.7 x as long as wide in the widest place, sensory appendages (Sa) 5.7 x as long as wide; segment IV about 3.0 x as long as wide at the widest place, about 1.8 x as long as sensory appendage of segment III. Anterior margin of nasale (Fig. 17): medial region (Mr) triangularly emarginate. Maxillary palp (Fig. 21): segments I (moderately widened apically) and II less slen- der than in L2: 1.3 x and 1.7 x as long as wide respectively; segment III more slender than in L2, 4.6 x as long as wide in the widest place and 2.6 x as long as sensory appendage (Sa).

Thorax. Pronotum (Fig. 31): with 22 pairs of setae (lacking a pair of setae) (A1–3, Da1–2, Db1–4, L1, L3–L5, L7–L11, P1–4), 5 pairs of pores (Ap1–5). Fore leg (Fig. 35): tibia (Tb, Fig. 35) with 17 setae (Ad1–4, Al1–2, Av1– 2, D1, Pd1–3, Pl1, Pv1–4) and a pore.

Abdomen. Urogomphus (Fig. 47): segment I gradually narrowed to apex, about 6 x as long as wide at the base, with 9 (same as L2) setae (D1–2, L1–3, Lv1, M1, V1–2) and a short seta (Ld1), dark brown cuticule with reticulate microstructure forming one ring basally; length ratio of segments I, II: 1.7:1.

FIGURES 7–10. Paederidus ruficollis (7–10A–C) and P. rubrothoracicus carpathicola (10D, E), larva. (7) Head of L2, dorsal; (7A) microstructure; (8) head of L2, left lateral; (8A) stemmata; (8B) trichobothrium near cluster of stemmata; (9) head of L2, ventral; (9A) apotome and tentorial pits; (10) right mandible of L2, dorsal; (10A) apical part of mandible; (10B, D) bunch of cuticular processes at the base of mandible of L2; (10C, E) bunch of cuticular processes at the base of mandible of L1. Abbreviations: Ap—apotome, Bm—group of microtrichia, Des—dorsal ecdysial suture, Dsm—dorsal sensillum, E—epicranial part, Ed—epicranialodorsal seta, El—epicranialolateral seta, Em—epicranialomarginal seta, Ep—epicranial pores, L—lateral seta, Lp—lateral pore, Lsm—lateral sensillum, Na—nasale, P—posterior part/posterior seta, Ps—preocular seta, Sm—sensillum, T—temporal seta, Tp—tentorial pit, Tpr—temporal pore, Trb—trichobothrium, V—ventral seta, Ves—ventral ecdysial suture, Vl—ventralolateral seta, Vp—ventral pore.

FIGURES 11–19. Paederidus ruficollis (11–17) and P. rubrothoracicus carpathicola (18, 19), larva. (11) Right antenna of L1, dorsal; (12) right antennal apex of L1, dorsal; (13) right antenna of L2, dorsal; (14) right antennal apex of L2, dorsal; (15) nasale of L2; (16) nasale of L2, right side of anterior part; (17) nasale of L1, right side of anterior part; (18) nasale of L2, right side of apex; (19) nasale of L1, right side of apex. Abbreviations: I–IV—antennal segments, Fc—frontal campaniform sensilla, Fdfrontal dorsal setae, Fl—frontal lateral seta, Fm—frontal marginal seta, Gp—glandular pit, Lt—lateral tooth, Mr—median region, Og—olfactory organ, Pmt—paramedian tooth, Ps—peg seta, Sa—sensory appendages, So—solenidium.

FIGURES 20–28. Paederidus ruficollis (20–23, 25, 28) and P. rubrothoracicus carpathicola (24, 26, 27), larva. (20) Epipharynx of L2; (21) apical part of right maxilla of L1, dorsal; (22) right maxilla of L2, dorsal; (23, 24) detail of right mala, ventral of L2; (25) hypopharynx of L2, dorsal; (26, 27) apical part of labium, dorsal, of L2 (26) and L1 (27); (28) labium of L2, ventral. Abbreviations: I–III—segments of maxillary or labial palps, Acp—row of cuticular processes along anterior margin of buccal cavity, Bc—buccal cavity, Cd—cardo, Dmt—dorsal microtrichia, Lg—ligula, Lp—labial palp, Lt—lateral tooth, Ma—mala, Mp—maxillary palp, Mr—medial region, Og—olfactory organ, Pcp—row of cuticular processes along posterior margin of buccal cavity, Pf—palpifer, Ph—pharynx, Pmnt—prementum; Pmt—paramedian tooth, Pp—pharyngeal pores, Ps—peg seta, Rw—ring of wrinkled cuticule, Sa—sensory appendage, Sm—sensillum, Ss—sclerotized strip, St—stipes, Trb—trichoboth-rium, Vmt—ventral microtrichia.

FIGURES 29–37. Paederidus ruficollis (29, 31–35) and P. rubrothoracicus carpathicola (30, 36, 37), larva. (29) Pro- (I) and mesonotum (II) of L2 with thoracic spiracle (A) and microstructure (B); (30) right half of pronotum of L2; (31) right half of pronotum of L1; (32) pro- (I), meso- (II) and metathorax (III) of L2, ventral; (33) fore leg of L2, anterior aspect with microstructure of coxa (A) and femur (B); (34) detail of fore tarsungulus of L2, anterior; (35) fore tibiotarsus of L1, anterior; (36) fore femur and tibiotarsus of L2; (37) tarsungulus of L2. Abbreviations: A—anterior seta, Ad—anterodorsal seta, Al—anterolateral seta, Alp—anterolateral pore, Ap—anterior pore, Av—anteroventral seta, Cx—coxa, D—dorsal seta, Da, Db—discal seta (rows a, b), Dp—dorsal pore, Fe—femur, L—lateral seta, P—posterior seta, Pd—posterodorsal setae, Pl—posterolateral setae, Ppposterior pore, Pr—presternum, Prhy—prehypopleuron, Pv—posteroventral setae, Sm—sensillum, Sn—sternite, St—sternum, Tb—tibia, Tg—tergal gland, Tr—trochanter, Trb—trichobothrium,Ts—tarsungulus, V—ventral seta.

FIGURES 38–43. Paederidus ruficollis , mature larva L2. (38) Abdominal tergites I and II with microstructure (A); (39) abdominal segments I–III, left lateral; (39A) spiracle of abdominal segment I; (40) abdominal segment I, ventral; (41) abdominal sternites II and III; (42) abdominal segments VIII–X, ventral, urogomphi cut off (43) abdominal segment VIII, left lateral. Abbreviations: A—anterior seta, Ap—anterior pore, Da, Db—discal seta (rows a, b), L—lateral seta, P—posterior seta, Pgparatergal gland, Ps—parasternite, Pt—paratergite, Sp—spiracle, St—sternite, Te—tergite.

FIGURES 44–50. Paederidus ruficollis (44, 45, 47) and P. rubrothoracicus carpathicola (46, 48), larva. P. ruficollis (49) and P. rub . carpathicola (50), adult male. (44) Abdominal segment IX, X and urogomphus of L2 dorsal with microstructure (44A, 44B); (45) abdominal segment IX and X of L2, right lateral; (46) right urogomphus of L2, dorsal; (47) right urogomphus of L1, dorsal with microstructure (47B); (48) abdominal segment IX, X and urogomphus of L1, dorsal with microstructure (48A); (49, 50) sternite VI, ventral. Abbreviations: I, II— segments of urogomphus, D—dorsal seta, L—lateral seta, Ld—laterodorsal seta, Lv—lateroventral seta, M—medial seta, St—sternite, Te—tergite, Ug—urogomphus, V—ventral seta.

FIGURES 51–56. Paederidus ruficollis (51, 53, 55) and P. rubrothoracicus carpathicola (52, 54, 56), adult. (51, 52) Habitus; (53, 54) aedeagus, lateral with (A) detail of apex; (55, 56) aedeagus, ventral with (A) detail of apex.

Figures

FIGURES 1 – 6. Paederidus ruficollis (1, 2, 4 – 6), P. rubrothoracicus carpathicola (3). (1) Egg with microstructure of surface (1 A). Mature larva. (2, 3) General; (4, 5) macro seta; (6) micro seta; (a – d) interspecific differences in coloration of: (a) head, (b) pronotum, (c) mesonotum and (d) base of urogomphi.