Serratia, Ho, - Z., 2019

Ho, - Z., 2019, The Luciolinae of S. E. Asia and the Australopacific region: a revisionary checklist (Coleoptera: Lampyridae) including description of three new genera and 13 new species, Zootaxa 4687 (1), pp. 1-174 : 145-146

Serratia gen.nov. Ballantyne

Figs 70−72 , 463−473

Type species: Serratia sibuyania sp. nov. by monotypy.

Diagnosis. Serratia gen. nov. is a S. E. Asian genus known only from a very few specimens all with pale brownish yellow dorsum and black elytral apices ( Figs 463−465 ). Males are distinguished from all other Luciolinae genera by the short rounded serrations on FS 1−4 ( Figs 465−469 ). It belongs in a group of genera characterized by: pronotal width less than width across elytral humeri, parallel-sided elytra, no MFC, an elongate slender aedeagus with LL largely concealed behind the ML when viewed from beneath. It is distinguished from all other Luciolinae genera by the serrate nature of antennal flagellar segments 1–4 in males and from which it derives its name, and an entire LO in V7 with a wide median anterior emargination. Other genera with this V7 emargination include Asymmetricata (which has an asymmetrical tergite 8), and Sclerotia which has a set of three sclerites surrounding the aedeagal sheath ( Serratia does not possess either of those features). Additionally males are distinguished from Colophotia in not having either a median carina on V7, or expanded and oblique PLP or bipartite LOs in V7; from Pteroptyx in not having an MFC, deflexed elytral apices, bulbous aedeagal sheath paraprocts and bipartite LOs in V7; from Pyrophanes (which has a MFC) and Pteroptyx testacea (which has no MFC), in not having either incurving lobes along V7 or bipartite LO; from Trisinuata by the entire LOs in V7 (those of Trisinuata are bipartite); from most Medeopteryx gen. nov. in not having deflexed elytral apices and trisinuate V7. It differs from Inflata indica in not having the bulbous ML of the aedeagus.

Male. Pronotum: dorsal surface without irregularities in posterolateral areas and longitudinal groove in lateral areas (1, 2); punctation dense; anterior margin not explanate (6); lateral margins subparallel-sided, the pronotum being slightly wider across its posterior area than elsewhere (C slightly>A, B); width <humeral width; anterolateral corners angulate r rounded ; lateral margins without indentation at mid-point, and sinuosity in either horizontal or vertical plane; without indentation in lateral margin near posterolateral corner, and irregularities at corner (15–18); posterolateral corners angulate, not projecting as far as median posterior margin; separated from it by scarce emarginations.

Hypomera: closed; median area of hypomeron not elevated in vertical direction (27); median area more widely flattened than elsewhere; pronotal width/ GHW 1.2–1.5.

Elytron: punctation dense, not linear (36), not as large as that of pronotum, nor widely and evenly spaced (34, 35); apices not deflexed (38), not emarginated (43); epipleuron and sutural ridge extend beyond mid-point, almost to apex but not extending around apex, neither thickened in apical half; no interstitial lines; elytral carina absent (54); in horizontal specimen viewed from below epipleuron at elytral base wide, covering humerus (48); viewed from above anterior margin of epipleuron arises well anterior to posterior margin of MS; epipleuron developed as a lateral ridge along most of length; sutural margins approximate along most of length in closed elytra; lateral margins parallel-sided.

Head: moderately depressed between eyes; well exposed in front of pronotum, not capable of complete retraction within prothoracic cavity; eyes moderately separated beneath at level of posterior margin of mouthpart complex; frons-vertex junction rounded, without median elevation (66); posterolateral eye excavation not strongly developed, not visible in resting head position (61); antennal sockets on head between eyes, not contiguous, ASD <ASW (ASD = ASW in Buru island specimens); clypeolabral suture present, flexible, not in front of anterior eye margin when head viewed with labrum horizontal; outer edges of labrum reach inner edges of closed mandibles. Mouthparts: functional; apical labial palpomere flattened, shaped like a short broad triangle not much longer than wide, with inner edge entire and approximately 1/3 as long as apical maxillary palpomere. Antennae ( Figs 465−469 ) 11 segmented; length approx. twice GHW; FS 1–4 slightly serrate; FS 5–9 elongate slender about 4 x as long as wide, not serrate; pedicel not produced; FS1 not shorter than pedicel. GHW/SIW 3–6/1.

Legs: with inner tarsal claw not split; without MFC; femora 3 not swollen and curved and tibiae 3 not curved; no basitarsi expanded or excavated.

Abdomen: ( Figs 470−473 ): without cuticular remnants in association with aedeagal sheath (131, 132); no ven- trites with curved posterior margins nor extending anteriorly into emarginated posterior margin of anterior segment (106–109); LO in V7 entire, occupying almost all of V7, and reaching to sides but not to posterior margin; median posterior margin of LO acute; median anterior margin of V7 LO narrowly to widely emarginated; a fine line running from the posterior area of the V7 emargination to the posterior margin of the LO is not elevated and the LO is apparently entire in V7 ; PLP narrower than MPP, apically rounded and produced laterally (sides of V 7 diverge posteriorly); posterior half of V7 not arched or swollen, muscle impressions not visible in this area; LO present in V6 , occupying almost all V6. MPP present, symmetrical, apex deeply medianly emarginated, and produced at the sides of the emargination into two elongate pointed projections which are horizontal at their bases; MPP not laterally compressed, ( L > W), apical points may incline dorsally but are not engulfed by T8 apex, without dorsal ridge, median longitudinal trough. V7 without median carina (114) (thin line in middle of V 7 LO is not elevated nor carina like), median longitudinal trough (117), incurving lobes or pointed projections (121, 127), median ‘dimple’ (128), or reflexed lobes (129). T7 without prolonged anterolateral corners. T8: symmetrical (184), W=L, widest across middle area of posterior visible portion, visible posterior area narrowing in posterior half, median posterior margin with a broad relatively shallow emargination and a deeper very narrow emargination in the middle; T8 lateral margins rounded; without prolonged posterolateral corners, median posterior projections, not inclined ventrally nor engulfing posterior margin of V7 nor MPP, extending beyond posterior margin of V7 ; T8 ventral surface with well-developed median longitudinal trough, without lateral depressed troughs’ median posterior ridge; T8 with short rounded projections occurring laterally just anterior to the anterior ends of the lateral ridges; concealed anterolateral arms of T8 elongate and wide, not laterally emarginated before their origins, not expanded dorsoventrally, expanded only in horizontal plane; without bifurcation of inner margin and ventrally directed pieces; lateral margins of T8 not enfolding sides of V7.

Aedeagus: L/W 5/1; apices of LL not visible from beneath at sides of ML depending on orientation of specimen, as in dried pinned specimens the ML is very narrow, LL/ML narrow; LL of equal length, slightly shorter than ML, contiguous or closely approaching along inner dorsal margins; LL narrowly separated longitudinally for most of their length; LL base width not = LL apex width which is much narrower than that of ML; dorsal base of LL symmetrical, evenly excavated; ML symmetrical, very narrow, without paired lateral teeth and tooth to left side, not strongly arched, apex not shaped like arrowhead, not bulbous, not inclined ventrally; BP not strongly sclerotised, not hooded, not strongly emarginated along anterior margin.

Female. Unknown.

Larva. Not reliably associated.

Etymology. Serratia (feminine) is a noun latinised from the English word serrate reflecting the nature of the antennal segments in the male.

Remarks. We know of four Luciolinae species described as having serrate or flattened antennae. Luciola intricata (Walker) has FS 2–8 serrate. It is known only from the type which is missing the abdomen, and while treated here as species incertae it is characterized from certain other features. Serratia gen nov. differs most obviously from those features of L. intricata we could determine in the number of, and outline of, the laterally produced antennal flagellar segments, and the nature of the apical labial palpomere (that of L. intricata is broadly flattened and triangular, with the inner margin dentate).

Olivier (1886) described as Luciola exstincta a single female from Alitaptap ( Philippines) which is of similar size but different colouration to Serratia sibuyania gen. et sp. nov., and in which the antennal ‘articulis 4–8’ were expanded. It is unclear if Olivier was referring to the flagellar segments only (as we do here), or more likely to the antennal segments counting the scape as number 1. If the latter then his reference is to flagellar segments 2–6 which is not inconsistent with what we describe here. We cannot locate the type of this species and it is difficult to assign males to any species described from a female only. Antennal modifications in the Luciolinae are more usually seen in males ( Ballantyne & Lambkin 2013). Bourgeois (1905) described as L. antennalis a single female from Sri Lanka as dorsally yellow with antennal segments 4−7 depressed. The type has not been located but the description of the antennal segments appears consistent with what we describe here. Bourgeois considered, and we agree, “elle mériterait peut-être de constituer un genre nouveau’.

Figures

FIGURES 70–77. Key to genera characters 11. 70–72 Serratia sibuyania gen. et sp. nov.; 73–75 Emarginata trilucida gen. nov. et comb. nov.; 76, 77 Colophotia praeusta. 70, 72, 73 dorsal habitus (70 anterior body only); 74 ventral habitus; 71 dissected terminal abdomen ventral; 75 ventrite 7 and elytral apices from below; 76, 77 ventrites 6, 7 from left (76) and below (77). Figure legends: MC median carina; MPP median posterior projection; PLP posterolateral projections.

FIGURES 463−473. Serratia sibuyania gen. et sp. nov. 463 holotype (USNM); 464 Romblon (USNM); 465−468, 470−473 Luzon H.S.B. (USNM); 469 Macassar (USNM). 463, 464, 465 habitus dorsal; 466, 468 habitus ventral (468 after removal of abdomen); 467 dorsal head. Pronotum and anterior part of elytra; 470 tergite 8 ventral; 471−473 abdomen: 471 intact, ventral; dissected, ventral; 473 dorsal.