Pygoluciola Wittmer, 1939

Fu, Xin Hua & Ballantyne, Lesley, 2008, Taxonomy and behaviour of lucioline fireflies (Coleoptera: Lampyridae: Luciolinae) with redefinition and new species of Pygoluciola Wittmer from mainland China and review of Luciola LaPorte, Zootaxa 1733, pp. 1-44 : 7-8

Genus Pygoluciola Wittmer, 1939

Pygoluciola Wittmer, 1939:21 . Ballantyne & Lambkin, 2006:22.

Luciola (Pygoluciola) – McDermott, 1966:115; Ballantyne, 1968:119; Ballantyne & McLean, 1970:233; Ballantyne & Lambkin, 2000: 82, 2001:363.

Type species.— Pygoluciola stylifer Wittmer, 1939 , by monotypy ( RMNH).

Diagnosis. Males exist in two forms, one in which the median posterior margin of both V7 and T8 are narrowed and strongly incline either dorsally (V7) or ventrally (T8) and may overlap each other in dried specimens. In the second V7 has no posterior projection, while T8 narrows very slightly and is narrowly downturned. Pronotum may have tubercles on posterolateral surface; lateral margins of pronotum diverge posteriorly; aedeagus with LL considerably longer than ML; basal piece may be asymmetrical bilobed; aedeagal sheath with narrow elongate anterior portion of sheath sternite and expanded posterior area; lateral arms of tergite clearly visible at sides.

Male (expanded format). Conforms to Ballantyne & Lambkin’s (2006) generic description with these additions/exceptions: Pronotum: irregular small tubercles may be absent in posterolateral areas. Elytron: epipleuron and sutural ridge extending to but not around rounded apex, neither thickened apically; when viewed from beneath the epipleuron conceals the elytral humerus; when viewed from above the epipleuron is first visible at the sides of the elytra anterior to the posterior margin of the MS. Abdomen: V7 may have LO extending over most of the area except for narrow lateral areas; anterior margin not emarginate; MPP of V7 slightly produced, apically rounded; PLP lacking as are any projections or processes along the rounded posterior margin of V7; T8: reasonably well sclerotised, a little wider than long, lateral margins subparallel sided in most of anterior visible area, in posterior 1/5 margins converge to a posterior margin which is slightly less than half the width of the most anterior (visible) portion, and is gently bisinuate, with posterolateral corners very narrowly pointed and slightly inclined ventrally; in pinned specimens a very narrow portion of the whole posterior margin of T8 inclines ventrally. Aedeagal sheath: up to 3.5 x as long as wide; anterior margin of tergite with transverse darker band. Aedeagus: ML up to ¾ as long as LL which taper towards their rounded apices.

Female. Similar to that described in Ballantyne & Lambkin (2006) except pronotum lacking posterolateral tubercles.

Larva. Reliably associated in Pygoluciola qingyu sp. n. only. Larvae conform to those of Pteroptyx valida Olivier ( Ballantyne & Menayah, 2002) and only differences are noted. Elongate slender, tapering in front and behind, flattened; lateral tergal margins thickened but not explanate, extend laterally slightly and cover the laterotergites which are not visible from above. Dorsal surface heavily and evenly pigmented (very dark brown) and heavily sclerotised (no membranous areas visible dorsally); narrow dark median line runs from anterior margin of prothorax to posterior margin of body segment 11; median line not depressed and margins finely and irregularly elevated; three thoracic and nine obvious abdominal segments [the tenth is interpreted, following Jeng et al. (2003a) as a narrow ring of cuticle immediately following segment 9 and before the origin of the pygopods]. All terga except terminal one bear four rounded projections along their posterior margins; terminal tergum with posterolateral corners obliquely truncate. Ventral surface of meso and metathorax with median sternal elements delimited by an elongate pleural suture from the lateral elements, the laterotergites; this ventral surface is composed of two areas in each segment, in the mesothorax an anterior presternum with paired laterotergites bearing well developed spiracles, followed by a median subrectangular sternal area bearing legs, above coxae episterna and epimera of meso and metathorax visible as thin sclerotised strands; similar arrangement in the metathorax except the metathoracic spiracle is rudimentary. Ventral surface of abdominal segments 1–8 have a single median sternal area per segment separated by elongate laterosternites from paired laterotergites (a pair per segment) bearing spiracles; laterotergites on segment 8 small and partially concealed by wider sternal plate which carries small round LOs at its posterolateral corners; venter of terminal segment lacking the differentiation of previous segments and bearing along its posterior margin pygopodia. Head and antennae of larvae as described for Pteroptyx valida ( Ballantyne & Menayah 2002) with following exceptions ( Figs 23–40 ): a well defined epicranial stem present behind median dorsal frontoclypeus; anterolateral margins of epicranial suture not clearly defined (visible as slightly darker line after head was cleared and ventral mouthpart complex removed); front margin of head ( Figs 24–25 ), with very short rounded median projection (nasale); 3rd segment of antennae ( Figs 28 , 29 ), with elongate slender tip subequal in length to thicker basal portion, and surrounded by 2 strong hairs; sense cone elongate slender. Mouthparts conform to general condition seen in Pteroptyx valida except for mandibles, which have 2 strong teeth on their inner margin ( Figs 25 , 27 , 30 ); labium ( Figs 31–32 ) with an anterior heart shaped prementum and two segmented labial palpi; posterior area consists an elongate mentum which lies between the stipes and extends almost as far as origins of cardines, and a pair of small triangular structures at its posterior end (which may represent the postmentum); apical segment of labial palpi elongate slender pointed, 3–4 × as long as width at base; apical segment of maxillary palpi elongate slender acutely rounded, 2.5 × as long as width at base ( Figs 25 , 26 , 31 , 32 ). Cardines with subtriangular anterior 1/3, and elongate slender rod like posterior 2/3 which may incline into head and thus not be clearly seen from below.

Remarks. This new species brings the number of described Pygoluciola species to six. Ballantyne (2008) describes another new species from the Philippines with abdominal modifications conforming to those previously described ( Ballantyne & Lambkin 2001, 2006). The record described here from mainland China is exceptional for several reasons: its geographic range, the synchronous flashing, and morphological diversity– it does not possess the elongate projections of male abdominal T8 and V7 previously thought characteristic of the genus. Ballantyne and Lambkin (2001, 2006) included keys to species but this species does not possess the terminal abdomen modifications characteristic of those five species and is not accommodated by that key. In the key to genera here it is the only representative of Pygoluciola keyed in couplet 5. Males and females are easily distinguished from existing species by the features listed, especially the dorsal colour pattern.

Figures

FIGURE 23. Larva: outline dorsal surface only.

FIGURE 24. Larva: head, semidiagrammatic, dorsal surface, antennae and mandibles only. M mandible; A 1 - A 3 antennal segments 1 - 3; S stemmata.

FIGURE 25. Larva: head anterior half dorsal. Scale bar = 0.43 mm. A, antenna; AM, antennal membrane; S, stemmata; M, mandible.

FIGURE 26. Larva: head, anterior half, ventral. Scale bar = 0.5 mm. L, lacinia; LP, labial palp; MP, maxillary palp; PM, prementum; POM, postmentum.

FIGURE 27. Larva: mandibles dorsal. Scale bar = 200 μm. M, mandible.

FIGURE 28. Larva: apical segments of left antenna from below. Scale bar = 150 μm. A 1 - A 3, antennal segments 1 - 3; SC, sense cone antenna.

FIGURE 29. Larva: left antenna detail segment 3 and sense cone. Scale bar = 43 μm. A 3, antennal segment 3; SC, sense cone.

FIGURE 30. Larva: ventrolateral view apical half of both mandibles showing inner teeth of left mandible. Scale bar = 136 μm. M mandible.

FIGURE 31. Larva: dorsolateral view, apices maxillary and labial palpi. Scale bar = 120 μm. LA, lacinia; LP, labial palp; MP, maxillary palp.

FIGURE 32. as for 31, ventrolateral view, R side only. Scale bar = 120 μm. MP, maxillary palp.

FIGURE 33. Larva: protergum (anterior end to top right).

FIGURE 34. detail 33, mid line. Scale bar = 120 Μm.

FIGURE 35. detail 33, anterior margin. Scale bar = 231 Μm.

FIGURE 36. detail 33, posterior margin (anterior end to bottom left). Scale bar = 0.6 mm.

FIGURE 37. Larva: mesotergum (anterior end to bottom left). Scale bar = 0.86 mm.

FIGURE 38. detail 37 mid line. Scale bar = 0.27 mm.

FIGURE 39. Larva: terminal tergum (anterior end to bottom left). Scale bar = 0.5 mm.

FIGURE 40. Larva: abdominal terga. Scale bar = 0.75 mm.