Abscondita terminalis (Olivier) Olivier, 2013

Ballantyne, Lesley, Fu, Xinhua, Lambkin, Christine, Jeng, Ming-Luen, Faust, Lynn, Wijekoon, W. M. C. D., Li, Daiqin & Zhu, Tengfui, 2013, Studies on South-east Asian fireflies: Abscondita, a new genus with details of life history, flashing patterns and behaviour of Abs. chinensis (L.) and Abs. terminalis (Olivier) (Coleoptera: Lampyridae: Luciolinae), Zootaxa 3721 (1), pp. 1-48 : 34-43

Abscondita terminalis (Olivier) comb. nov.

Figs 20–29

Luciola terminalis Olivier, 1883:330 ; 1891:602; 1902:87; 1907:54; 1912:90.

Luciola praeusta Kiesenwetter. Gorham, 1895:305 . McDermott, 1966:112. Partim.

Type. VIETNAM: Male. Labelled 1. Type (printed); 2. La Khone D’Harmand (handwritten); 3. Luciola terminalis ♂,♀ (Handwritten), Ern. Oliv. (printed) (examined by Jeng et al. 2003:255). (MNHN).

Diagnosis. Having yellowish orange pronotum and elytra with a apical dark brown area; males distinguished most obviously from the similarly coloured Abs. chinensis by the colour of the abdominal ventrites ( chinensis almost always have V5 completely dark and few specimens have dark markings on the preceding ventrites. while terminalis usually has V5 with lateral dark markings and as many as 3 other ventrites similarly marked), the outline of the tip of the male aedeagal sheath sternite, and the flashing pattern which is a train of pulses. Females macropterous coloured like male; usually distinguished from females of Abs. chinensis by the more extensive ventral abdominal colouration ( chinensis females have dark markings restricted to the posterolateral areas of V5 only; most terminalis females have dark posterolateral markings on at least V4, 5 and sometimes more; only pattern 6 below approaches that of chinensis ). Larvae very similar to those of Abs. terminalis with paired pale patches in the anterolateral areas of the protergum. The male flashing pattern, most often seen in paddies and open areas, is a train of pulses lasting ca 1 sec with ca 1.5 sec intervals.

Specimens examined ( Fig. 21 ). Collector is X.H. Fu. CHINA: N 30.38, E 114.32 Hubei Province, Wuhan City, Liufang Street, 49 males, 3 females. N 26.264, E 117.64 Fujian Province, Samming City 10 males. N 24.918, E 118.59 Fujian province Quanzhou City 4 males, 3 females. N 24.514, E 117.65 Fujian province Changtai county Zhangzhou City 2 males. N 22.97, E 115.33 Fujian province Haifeng County, Shanwei City male. N 21.92, E 101.28 Yunnan Province, Jinghong City, Xishuangbanna Botanical Garden 189 males, 378 females. Additional specimens examined: Taiwan: Taipei Co., Hwangshi, 29. Iv. 1997, 2 males, M. F. Chen. Taipei Co., Guangshing, 26. Vii. 1997, 1 male, M. F. Chen. Taipei Co., Guangshing, 27. Vii. 1997, 6 males, 1 female, C. C. Chang. Taoyuan Co., Dashi, 4. Iv. 1998, 1 male, Y. J. Chen. Taoyuan Co., Dashi, 20. V. 1998, 1 female, Y. J. Chen.

Male. 8.8–11.3 mm long; 2.6–4.2 mm wide (variation shown in Table 10). Colour ( Figs 20 A, B; 22): Pronotum orange yellow except for narrow median sulcus sometimes appearing reddish yellow; MS and semitransparent elytra orange yellow, except for apical dark brown area (0.6 of total length) and paler suture with underlying fat body along most of its length; MN paler yellow with underlying fat body contributing to colour; head between eyes, antennae and palpi dark brown; ventral thorax orange yellow; all legs orange yellow except for brown tips of femora and dark brown tibiae and tarsi; abdomen orange yellow with ventral brown markings as follows ( Fig. 22 ) (number of males in brackets): 1. (V5 completely dark, V3 with posterolateral drak markings separated by <their width, V3 with posterolateral dark markings separated by> their width) Mt Jigong (2). 2. (V5 completely dark except for a narrow paler anterior margin, V3, 4 with isolated single posterolateral dark spots) Longxi County Samming City (10). 3. (As for pattern 2 except dark marking in V5 retracted from all margins (possibly a consequence of dehydration) Quanzhou City (1). 4. (V5 completely dark except for small median emarginations along anterior and posterior borders) Jinghong City Botanical Gardens (21). 5. (V5 almost completely dark except for narrow pale median area, V3 with lateral dark areas separated by <their width, V2, 3 with small posterolateral dark markings) Mt Lianhua Haifeng county (1). 6. (V5 with extensive dark markings separated in middle by <their width and almost continuous along posterior margin) Changtai county (2); Quanzhou City (3). 7. (V5 dark laterally, markings separated by less than their width, V3, 4 with posterolateral dark spots) Jinghong City Botanical gardens (168); type male. 8. (V3, 4, 5 with posterolateral dark areas separated by their width (in V5) or <in V3, 4) Wuhan City Liufang St. (49). LO in V6, 7 very white, with very narrow black lateral margins of V6, and lateral and posterior margins of V7 usually appearing black; T5, 6, 7, 8 black, T5 very dark brown across most of median area, remaining tergite colouration patterns as follows: 1. (T2, 3, 4 having mottled dark brown markings across most of surface) Jinghong City Gardens 127/189, Liufang Street 49/49; Meishan Town 2/4, Zhangzhou City ½, Samming City 10/10; 2. (mottled brown markings restricted to T4, remainder pale semitransparent yellowish) Jionghong City gardens 62/189, Meishan Town 2/4, Zhangzhou City 1/ 2; dorsally reflexed lateral and posterior margins of V7, and lateral margins of V6 black, of V5 black with anterior ¼ or less pale; remainder of reflexed margins pale brown. Pronotum: 1.35–2.15 mm long; 2.5–3.5 mm wide; W/L 1.6–1.9. Elytron: 7.1–9.3 mm long. Head: GHW 1.9–2.7; SIW 0.45–0.65 mm; ASD> ASW. Apical labial palpomere with 3 or 4 teeth along the inner margin; 3 teeth in all populations except 137/378 from Jinghong City Gardens, where males have 4 teeth. Aedeagal sheath with sternite terminated by two elongate apically rounded, hairy lobes ( Fig.23 A, B).

Female. 9.9–13.2 mm long; 1.9–4.7 mm wide; (variation shown in Table 11); macropterous and observed in flight. Colour: as for male with these exceptions—ventrites anterior to LO yellow with posterolateral brown markings on V2–5 (Only pattern 4 below has dark markings restricted to V5), patterns as follows: Abdomen orange yellow with ventral brown markings as follows (number of females in brackets): 1. (dark lateral markings V2-5, widest in V5 and separated by their width) Jinghong City Botanical Gardens (138). 2. (As for 1 but markings in V3-5 only) Jinghong City Botanical Gardens (190); Quanzhou City (3). 3. (reduced dark lateral markings in V4, 5 only separated by twice their width) Jinghong City Botanical Gardens (20); Wuhan City Liufang St. (1). 4. (dark markings posterolateral corners V5 only) Wuhan City Liufang St. (2). 5. (dark lateral markings not discernable) Jinghong City Botanical Gardens (30). Tergite colouration patterns as follows: 1. (T7, 8 pale; T6 dark brown with median pale area; T5 dark brown) Jinghong City Gardens 39/378; Liufang St 1/3. 2. (T7, 8 pale; T6, 7 entirely dark brown; T5 dusky brown) Jinghong City Gardens 157/378; Liufang St 2/3; Mt Lianhua 1/1. 3. (As for 2 with dusky markings on T2, 3) Jinghong City Gardens 182/378; Meishan town 3/3.white LO confined to V6, all abdominal tergites yellow. Pronotum: 1.75– 2.4 mm long, 3.2–4.1 mm wide. Elytron: 8.2–10.9 mm long. Head: GHW 1.7–2.3 mm; SIW 0.5–0.7 mm; ASD> ASW; antennae almost always slightly longer than 2 x GHW. Mouthparts: apical labial palpomere with three teeth along inner margins except for 137/ 378 females from Jinghong City Gardens with 4 teeth.

Larva ( Figs 20 D, E; 25). Paired pale patches in the anterolateral areas of the protergum, similar to larva of Abs. chinensis and not distinguished from it.

Biology: Larvae, active on the wet soils of the paddies and grass margins ( Fig. 6 B; Fig. 26 A), attacked and ate both living and dead ants and small insects. In the laboratory, larvae preyed on termites ( Reticulitermes chinensis Snyder, 1923 )( Fig. 26 B) and adult scuttle flies ( Megaselia scalaris Loew, 1866 ). Captive larvae fed on fresh-killed mealworms ( Tenebrio molitor ). Cannibalism was observed when larvae lacked food. Larvae, which were observed glowing both in the wild and the laboratory, had six instars, taking almost a year to mature ( Table 12 ). Final instar larvae constructed pupal cells in soil taken from the collection site ( Fig. 26 C) with pupal period averaging 10.1±1.4 days (n=20). Pupae were observed (after 3 minutes of dark adaption) to emit a continuous pale luminescent glow from the entire body except the darkened compound eyes and hind wings ( Fig. 27 A, B, C, D). The bodies of newlyemergent adults were also observed weakly glowing ( Fig. 27 E), though this luminescence gradually disappeared after ca 3 hours when sclerotization was complete. Eclosing males exhibited protandry and a 1.06:1.00 sex ratio of male (n=85) to female (n=80)( Fig. 28 ). Laboratory-reared males (n=10) could mate twice but females only mated once (n=10) in 24 hours. Mated females (n=15) laid an average of 47.6±3.7 eggs individually. Eggs hatched 17 to 22 days later. In captivity, the mean life span of males (n=17) was 10.2±1.8 days while female (n=14) span averaged 11.9±1.7 days.

instar Number (n) Body length Body width (mm) Head width (mm) Pronotum width Instar period (d) *

(mm) * * * (mm)*

Adult mating season, with one generation a year, ranged from 14 May to 13 June all three years at the site in Wuhan, Hubei Province. First warm-up flashes began 27 min after sunset; first flying males flashed 33 min after sunset and continued for two hours displaying above and near the paddies, with peak display occurring one hour after sunset. When patrolling, males usually flew 2 metres high in a straight and rapid manner while flashing their mostly 4–8 pulse (range 2–13) flash trains ( Fig. 29 A). At 20.2°C and 94.4% humidity, mean flash duration of flying flashing male is 174.68±14.91 ms, interflash interval 102.65±25.68 ms, interval 1508.20±580.94 ms and rate 0.39 ±0.08 (flashes/ sec) (n=14) ( Fig. 29 A). Females, cryptically positioned in the tall grass of the paddy margins, signalled with a fast single pulse seemingly independent of the male multi-pulse flash train. Female courtship flashes had mean durations of 236.69±43.00 ms, flash interval 367.76±165.53 ms and rate 1.81±0.56 (n=7) ( Fig. 29 C). After two hours of flash-train flashing, few males remained in courtship flight, but many males were observed perched on the tips of grass emitting a different flash. The perched flash pattern consisted of flashing slowly via the first segment of light organ (V 6) with flash duration 238.19±73.61 ms and interval 767.39±189.67 ms (n=14) followed by a quick bright two segments of light organ (V 6 and 7) with flash duration 255.17±70.56 ms and interval 238.95±117.29 (n=11) ( Fig. 29 B). These perched males flashed at least one minute, paused for twenty or thirty seconds, and then repeated the perched flashes. During the field studies, one male was observed to land close to the female, mount and mate quickly within one minute. No flash dialogues were observed during copulation. In the field, an apparent changing operational sex ratio was noted with males appearing relatively more abundant early in the season and females more numerous by season’s end (unquantified observation).

Females were observed to climb on the tips of grass or open ground and flash later at night after the males had ceased flying. Bioluminescence emission was yellow (λ max = 560 nm) for both sexes (females n=6, 30 readings; males n=5, 25 readings).

A centipede Scolopendra subspinipes mutilans Koch was observed feeding on a still glowing male Abs. terminalis . However, observation revealed that nocturnal orb-weaver spiders including A. ventricosus were more common predators of the courting males.

Remarks. As with the preceding species we are basing our identifications of this species by comparison with Jeng et al. (2003), who differentiated between the Taiwanese populations of terminalis and praeusta using the same features of abdominal colour and aedeagal sheath features as we do here.

Yiu Vor dissected specimens he identified as L. terminalis from Tin Sam Tsuen and Sha Lo Tung in Hong Kong and established the aedeagal sheath structure as consistent with Jeng et al. (2003) (Yiu pers comm.). The male multi-pulse flash patterns and flight behaviour (May–Sept in open areas) were also consistent with our studies. He did not believe L. praeusta ( sensu Jeng ) had yet been found in Hong Kong (Yiu pers comm.).

Jeng’s observations on specimens he identified as terminalis in Taiwan differ, however, and were observed from late spring to summer. Individuals preferred using semi-open fields as habitats, especially around water environments. Their males usually flew low and slow, with very bright flash in flight.

Number Flash duration Interflash interval Interval Rate (flashes/

measured (ms) * (ms) * (ms) * sec) *

Flying male 14 174.68±14.91 102.65±25.68 1508.20±580.94 0.39 ±0.08

Figures

FIGURE 6. Habitats. A, Abs. chinensis (Mt. Dabie, Yingshan City, Hubei Province) and B, Abs. terminalis (Red flag village, Wuhan City, Hubei Province).

FIGURE 20. Habitus Abscondita terminalis. A, B male; C female; D, E larva; F male pupa (A, D dorsal; B, C, E, F ventral) (Scale bar = 5 mm).

FIGURE 21. Distribution of Abs. terminalis in China.

FIGURE 22. Abs. terminalis male ventral abdomen showing markings and light organs.

FIGURE 23. Abs. terminalis male genitalia. A, B aedeagal sheath; C, D, E aedeagus (A, C dorsal; B, D ventral; E right lateral) (Scale bar = 1 mm).

FIGURE 24. Abs. terminalis Female reproductive system and bursa. A entire system with V 8 intact, spermatophore digesting gland to top of figure. B detail bursa hooks. (Scale bar = 1 mm). BU, bursa; SDG, spermatophore digesting gland; V, valvifer.

FIGURE 25. Abs. terminalis fifth instar larva SEM. A, B, C head; D part of labium, maxilla and left antenna; E larva. (A anterior view slightly to one side with ventral surface uppermost; B, E, dorsal; C, D ventral). A 1 antennal segment 1; A 2 antennal segment 2; A 3 antennal segment 3; SC sensory cone; LP labial palp; G galea; MXP maxillary palpus.

FIGURE 26. Abs. terminalis life history. A observation site-paddies (Red flag village, Wuhan city); B larvae feeding on termites Reticulitermes chinensis; C pupal cell; D male and female in copulo.

FIGURE 27. Luminescence of pupae and adults of Abs. terminalis (Scale bar = 5 mm). A 3 - day old male pupa ventral (F 4.5, ISO 200, 266 s); B 3 - day old male pupa lateral (F 4.5, ISO 200, 439 s); C 3 - day old male pupa dorsal (F 4.5, ISO 200, 490 s); D 7 - day old female pupa ventral (F 14, ISO 800, 625 s); E, newly-emergent female adult within 3 hours (F 4.5, ISO 640, 301 s).

FIGURE 28. Number of emergent adults of Abs. terminalis from Laboratory rearing across a one month period (Photoperiod = 12: 12, Temperature 25 ° C, humidity 70 – 80 %.)

FIGURE 29. Abs. terminalis flash pattern. A flash pattern of patrolling male; B flash pattern of male perched on tip of grass; C calling signal of female.

Tables

TABLE 12. Development of larval Abs. terminalis.

1st	11	3.04±0.25	0.68±0.06	0.29±0.03	0.69±0.05	16.9±2.5
2nd	10	4.22±0.63	0.99±0.07	0.42±0.04	1.01±0.04	16.1±1.2
3rd	9	7.29±0.50	1.51±0.05	0.59±0.08	1.57±0.04	26.7±3.1
4th	17	11.03±0.18	2.29±0.05	0.67±0.03	2.34±0.04	29.8±3.4
5th	16	15.40±0.17	2.72±0.06	0.76±0.03	2.93±0.11	38.8±2.5
6th	12	17.40±0.40	2.89±0.09	0.95±0.02	3.01±0.03	159.5±8.8