Sclerotia Ballantyne, gen. nov.
Creators: name: Ballantyne, Lesley A.
name: Lambkin, Christine L.
name: Luan, Xin
name: Boontop, Yuvarin
name: Nak-Eiam, Sorasak
name: Pimpasalee, Suttisan
name: Silalom, Sommyot
name: Thancharoen, Anchana
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Lampyridae
Sclerotia

description: Sclerotia Ballantyne gen. nov.
(Figs 17−46, 63−138)
Type species. Luciola aquatilis Thancharoen, 2007.
Ballantyne (1987b) first identified the presence of sclerites surrounding the aedeagal sheath in specimens she incorrectly identified as Luciola japonica (the species is Sclerotia aquatilis and is addressed in this paper). Jeng et al. (2003: Fig. 14) illustrated two lateral sclerites the arms of which envelop the sheath from the sides, and a single ventral sclerite in what we now know is Scl. flavida (they misidentified their species as Luciola substriata). Thancharoen et al. (2007) did not investigate their presence in L. aquatilis but presented clear photos of the elytral punctation. Because the sclerites appear to be associated with the linear elytral punctation an attempt was made to survey those 12 species described originally with elytral punctures in lines (Thancharoen et al. 2007: Fig. 5; McDermott 1966), and to locate types and identified material. We were successful in locating types of seven species and our reassessment is presented below (Table 3).
Diagnosis. Sclerotia gen. nov. is distinguished from all other Luciolinae genera as follows: Males: most species with dull brownish yellow dorsum often with elytral apices black tipped; elytra with lines of punctures running parallel to each other over most of the surface, entire LO in V7 with an anterior median emargination, and LO assuming either a heart or U shape depending on the depth of the emargination; three strongly sclerotised sclerites surround the aedeagal sheath, one ventral and two lateral (sclerites may be visible from below through the light organ emargination, or from above through the tergites depending on the nature of preservation of the specimen); aedeagal sheath sternite sloping to left and either emarginate or prolonged along its posterior margin; aedeagus short and squat, with broad LL visible beside ML; LL slightly uneven in length. Females: macropterous and assumed capable of flight; elytral punctures as for male; LO confined to V6 with V7, 8 medianly emarginated along their posterior borders; bursa without plates. Larvae: Metapneustic, without gills in later instars; lateral bristles in first and possibly second instars may function as gills (Fu & Ballantyne 2009); back swimmers common at or just beneath water surface with their terminal spiracles piercing the surface, and their morphology is an adaptation to this more exposed mode of life (Fu et al. 2005a); apparently without defensive glands (Fu & Ballantyne 2010, Fu et al. 2012b).
.
Luciolinae described with linear elytral punctation Comments**
(from Thancharoen et al. 2007)
Luciola ambita Olivier 1909 (Java) Type in MNHN; anterior margin of light organ in V7 not
emarginated; elytral punctation not in lines (LB examination 2013). See Figs 4−6
L. aquatilis Thancharoen 2007 (Thailand) * Type AMNH
L. delauneyi Bourgeois 1890 (Vietnam) Type MNHN without head and pronotum; possibly should be assigned to Curtos (LB examination 2013). See Figs 7 − 9 L. flebilis Olivier 1909 (Sumatra) Type MCSN; elytral punctation not in lines. See Figs 10−12. L. semilimbata Olivier 1883 (India) Assigned to Pyrophanes in Ballantyne & Lambkin 2013 = L. venusta Olivier 1883
L. semimarginata Olivier 1883 (Celebes) ** Specimens in NHML and MNHN have trisinuate ventrite 7 (LB
examination 2013). See Figs 13−16. L. seriata Olivier 1891 (Burma) * Type MCSN
L. substriata Gorham 1880 (India) * Type not located; Jeng et al. (2003) synonymised this with L.
formosana Pic (1916); this synonymy is rejected here and Taiwanese population assigned to L. formosana.
L. varia Olivier 1908 Types in Deutschen Entomol. National Museum, and MNHN (not examined for this study but probably belongs in Sclerotia gen. nov.)
Footnote: **comments about possible taxonomic status expressed above is that of Ballantyne alone and has not yet been formalised (Ballantyne & Lambkin in prep.)
Male. BL/ W 2.3 –3.2. Pronotum (Figs 17, 19, 21, 23, 25, 27, 28, 39, 42, 43, 74, 86, 93, 97, 119, 131, 133, 135):W/L 1.6–2.1; L/BL 0.14–0.19; W/ GHW 1.3–1.5; dorsal surface without irregularities in posterolateral areas and longitudinal groove in lateral areas (1, 2); punctation dense; anterior margin not explanate; pronotum either as wide across middle as in posterior third (B=C) or wider across posterior area than rest (C>A, B); pronotal width either very slightly less than or subequal to humeral width; median anterior margin broadly rounded not usually projecting anteriorly much if at all beyond rounded obtuse anterolateral corners; lateral margins divergent posteriorly with a slight convergence in posterior 1/6, or divergent posteriorly in anterior 1/2 with posterior half subparallel; without indentation at mid-point, or sinuousity in either horizontal or vertical plane (16, 17); subparallel sided margins straight; without indentation in lateral margin near posterolateral corner, and irregularities at corner (17, 18); posterolateral corners rounded obtuse or slightly less than 90° and inclined obliquely to the median line; posterolateral corners either projecting as far as the median posterior margin or beyond and separated from it by a shallow emargination
Hypomera: closed. Median area of hypomeron not elevated in a vertical direction (27); hypomeron not closely adpressed.
Elytron (Figs 17, 19, 21, 23, 25, 27, 28, 39, 42, 43, 74, 86, 93, 97, 119, 131, 133, 135, 136): EL/BL 0.80−0.82; elytra subparallel-sided in anterior 2/3, tapering slightly in posterior 1/3; contiguous along suture almost to apex, punctation dense, linear, lines of punctures parallel over much of the elytron, not as large as those of pronotum, nor widely spaced; apices not deflexed (38); epipleuron and suture extend beyond midpoint to apex without any further expansion of either; interstitial lines either evanescent or up to 4 lines well defined; elytral carina absent (54); epipleuron expanded at base, covering humerus from below either completely or almost so and arising anterior to posterior margin of the MS (from above); epipleuron developed as a lateral ridge along most of its length; sutural margins approximate along most of their length in closed elytra; lateral margins parallel sided or slightly convex.
Head (Figs 18, 20, 22, 24, 26, 40, 44, 75, 94, 98. 132, 134, 137): SIW/GHW 0.15– 0.17; shallowly depressed between eyes; moderately exposed in front of pronotum, not capable of complete retraction within the prothoracic cavity; eyes moderately separated beneath at level of posterior margin of mouthpart complex; eyes above labrum close; frons vertex ‘junction’ rounded; posterolateral eye excavation not developed (61); antennal sockets on head between eyes, separated by <ASW or contiguous; clypeolabral suture present, flexible; labrum small, transverse, outer edges of labrum reach inner edges of closed mandibles. Mouthparts functional; apical segment of labial palpi strongly flattened, in the shape of a wide triangle, with inner edge dentate (number of teeth may differ from R to L palp in the one individual). Antennae 11-segmented; length greater than GHW up to twice GHW (longer than 2 x GHW in Scl. seriata); no segments flattened, shortened, or expanded; pedicel not produced; FS1 not shorter than pedicel; FS elongate slender (about 3 X as long as wide); FS 7–9 not conspicuously shorter than rest.
Legs (Figs 18, 20, 22, 24, 26, 40, 44, 75, 87, 94, 98, 132, 134, 137): inner tarsal claw not split; without MFC (96); no femora or tibiae swollen or curved (97, 98, 99); no basitarsi expanded or excavated (100).
Abdomen (Figs 18, 20, 22, 24, 26, 40, 44, 63, 75, 81, 94, 98, 120, 128, 132, 134, 137, 138): no ventrites with curved or emarginated posterior margins (106, 107). V7 with lateral margins converging posteriorly to a short squat symmetrical apically rounded MPP which does not curve dorsally. Light organs: LO in V7 with a median anterior emargination which may be shallow or deep; LO reaching to both sides and posterior margin or to neither; often reaching well into MPP; shallowly emarginated LO in V7 may occupy most of the area of V7 (e.g. Figs 40, 44, 75, 81), deeply emarginated LO occupying less (e.g. Figs 63, 120); LO present in V6, occupying almost all the area. MPP: present, symmetrical, apex rounded, entire, not laterally compressed, short, not inclined dorsally nor engulfed by the apex of T8, but lateral margins of T8 often enfolding sides of V 7 in pinned specimens (Figs 81, 82); without dorsal ridge and median longitudinal trough (172, 176). V7: ventral surface without median carina (114), median longitudinal trough (117), anteromedian depression on face of LO (156), median ‘dimple’ (128); dorsal surface V7 without reflexed lobes (129); posterior margin V7 without PLP, incurving lobes or pointed projections (121, 127); T7: posterolateral corners may overlap V7 at sides. T8: not strongly sclerotised, with rounded sides, symmetrical, visible posterior area narrowing before origin of anterolateral projections, with shallow and narrow median posterior emargination, without prolonged posterolateral corners, median posterior projections, not inclined ventrally nor engulfing the posterior margin of V7 nor the MPP (sides of T 8 may engulf sides of V 7 in pinned specimens), nor extending conspicuously beyond the posterior margin of V7; T8 ventral surface (Figs 29−31, 45, 46, 72, 77−80, 90, 111, 128) without flanges (198), lateral depressed troughs (206), median longitudinal trough (194), asymmetrical projections (207), median posterior ridge; concealed anterolateral arms of T8 elongate, longer than visible posterior portion of T8, narrow and expanded dorsoventrally; not laterally emarginated before their origins, without bifurcation of inner margin and ventrally directed pieces (217).
Aedeagal sheath sclerites (Figs 29, 30, 31, 45, 46, 65−72, 78−80, 89, 90−92, 103−107, 111−114, 128−130): three sclerites surround the sheath; in a live specimen they are embedded in a thick band of muscle surrounding the apical area of the sheath, one beneath (e.g. Fig. 29 “3”) and two at the sides (Fig. 29 “1, 2”); lateral sclerites in close association with the anterior margin of the entire portion of T8, with broadly expanded dorsal surfaces attaching mainly the ventral surface of T8 (Fig. 29; Jeng et al. 2003: Fig 14); median ventral sclerite somewhat flattened and plate like, often circular in outline and may have elevated dorsal margins; muscles from this single sclerite attach in part on the dorsal surface of V7 and are at least partially responsible for the emargination of the LO there; right ventral sclerite (Figs 29−31 “1”) in the form of an elongate triangle, longer than left sclerite; always with an elongate slender apically pointed posterior arm extending across T8 to the left of the midline, and attaching to the underside of T8; right sclerite expanding along its outer (right) margin which is produced into 2 or more projections which incline dorsolaterally and ventrolaterally; left sclerite(Figs 29−31 “2”) always smaller than right and not extending to the right beyond the median line of T8; usually subtriangular in form with a number of projections arising from the left side.
Aedeagal sheath (Figs 29 “4”, 32−35, 72, 77, 91, 92, 101, 102, 121, 126, 127): elongate, asymmetrical, with tergite wider than sternite and visible in posterior half narrowly on left side and more widely on right; never> 4 times as long as wide; without paraprocts; asymmetrical in posterior area where sheath sternite inclines to the left from point of attachment of the tergite and narrowed anterior right arm of tergite is visible beside the sternite (Fig. 32); tergite arms attaching asymmetrically to sides of sternite, left arm at about 1/4 length from distal end of sternite (Figs 32, 33 “B”), and right arm at about 1/2 length sternite from proximal end (Figs 32−35 “A”); sternite not angulate on left or right sides, posterior half approaching subparallelsided; often with obliquely inclined narrow ridge in posterior area of sternite running from basal left to distal right (Figs 30, 45, 46 “5”, 77, 102, 11); posterior margin either apically emarginated, truncate (Fig. 77), or prolonged on one side; emargination may be symmetrical, in centre or off centre, or asymmetrical with only one side of the posterior margin extended (Figs 73, 121, 127); anterior half of sternite broad, apically rounded; tergite not subdivided, without projecting pieces along posterior margin of tergite 9, without transverse band across anterior margin of tergite; midanterior margin of tergite either emarginated or narrowly produced (Figs 33−35 “D”, 91, 101, 126).
Aedeagus (Figs 36−38, 83−85, 88, 108−110, 115−117, 123−125): L/W <3/1; LL lack lateral appendages, are visible from beneath at sides of ML, LL/ML moderate; LL may be of equal length (Figs 115−116), sometimes appearing of unequal length which may depend at least in part on the orientation of the specimen; LL usually of unequal length, with right LL slightly longer than the left in Scl. aquatilis (Thancharoen et al. 2007: Fig. 2 a,b), Scl. brahmina (Figs 37, 38), Scl. flavida (Fig. 88) and Scl. substriata (Figs 123, 124); LL slightly shorter than ML, not diverging along inner margins (except for Scl. carinata where they diverge along their length), and separated there by> half their length; LL usually bearing small incurving tooth at their inner apices; LL base width not = LL apex width which is subequal to or narrower than that of ML with apices expanded in a horizontal plane; base of LL (from above) symmetrical, not excavated, anterior median margin prolonged and broadly rounded or truncate; LL without lateral hairy appendages along their outer ventral margins, without projection on left LL only; inner margins without slender leaf-like projection. ML symmetrical, without paired lateral teeth and tooth to left side, not strongly arched, and apex either slightly acute or rounded, not bulbous, not inclined ventrally; base of ML rounded with outline following that of BP (Fig. 37 “F”); BP well defined and long, narrow, (lateral margins of BP project posteriorly to about 0.4–0.6 of the length of aedeagus Fig. 37 “E”), not strongly sclerotised, not hooded, not strongly emarginated along anterior margin.
Female (Figs 41, 76, 95, 96, 99, 100). Macropterous. Pronotum without irregularities in posterolateral areas; punctation moderate to dense, pronotum subequal to or <humeral width; without indentation of lateral margin, irregularities at posterolateral corner. Elytral punctation not as large as that of pronotum nor evenly spaced; without interstitial lines; elytral carina absent. No legs or parts there of swollen and /or curved. LO only in V6, without any elevations or depressions or ridges on V7. Bursa without plates. Styli short and broad. Females are not further investigated here as they will be part of a wider investigation into reproductive anatomy in the Luciolinae (Ballantyne and Fu in prep.)
Larva (Fu et al. 2012b Figs 31−42, 70, 83−86). Body: flattened, well sclerotised plates covering dorsal and ventral body surfaces (no exposed membranous areas), tergal plates not laterally explanate and laterotergites not visible from above beside abdomen; ventral plates of abdomen consisting of median sternal plate and lateral paired laterotergites carrying spiracles; abdomen without laterosternites; spiracles arising from posterolateral areas of the dorsal surface of abdominal segment 8. Mouthparts: Mandibles with narrow retinaculum, bearing a dense profusion of curved setae; inner edge of apical half without row of very short setae; most of dorsal surface irregular and resembling overlapping scales; single line of thick stout setae bordering lateral margin of scaled area on dorsal surface, setae often split at apices; outer edge of mandibles bearing hairs along most of length. Maxillae with apical palpomere with sense organs along ventral surface. Labium with palpi moderately separated at their bases, apical palpomere with sense organs along ventral surface; ventral surface of heart shaped prementum with hairless “keel” about as long as wide. Antennae: AS 3 elongate, surmounted by closely adpressed short finger like projections, subequal in length and width to adjacent sense cone; apex of AS 2 not strongly oblique.
Etymology. The generic name is latinised from the English word sclerite, referring to the block of three sclerites surrounding the aedeagal sheath in this new genus.
description: Published as part of Ballantyne, Lesley A., Lambkin, Christine L., Luan, Xin, Boontop, Yuvarin, Nak-Eiam, Sorasak, Pimpasalee, Suttisan, Silalom, Sommyot & Thancharoen, Anchana, 2016, Further studies on south eastern Asian Luciolinae: 1. Sclerotia Ballantyne, a new genus of fireflies with back swimming larvae 2. Triangulara Pimpasalee, a new genus from Thailand (Coleoptera: Lampyridae), pp. 201-249 in Zootaxa 4170 (2) on pages 209-214, DOI: 10.11646/zootaxa.4170.2.1, http://zenodo.org/record/257995