Myrmeleon littoralis Miller & Stange, 1999

Lin, Yu-Hsiu Hugh, Ko, Chiun-Cheng & Tseng, Hui-Yun, 2024, Taxonomic revision of the antlion tribe Myrmeleontini (Neuroptera: Myrmeleontidae) of Taiwan, European Journal of Taxonomy 969, pp. 1-61 : 22-27

Myrmeleon littoralis Miller & Stange, 1999

Figs 1D , 11–13

Myrmeleon littoralis Miller & Stange in Miller et al., 1999: 64. Type locality: Taiwan (Miaoli).

Myrmeleon littoralis – Stange et al. 2003: 116. — Wang et al. 2018: 106.

Myrmeleon (Myrmeleon) littoralis – Stange 2004: 331. — Lin et al. 2019: 140.

Material examined

Holotype TAIWAN • ♂ (photos examined); Miaoli County, Tongxiao Township, Tongxiao Resort Beach ( Tonshou Resort Beach ); 24°29′47.5″ N, 120°40′20.5″ E; 3 May 1998; Robert A. Miller, Lionel A. Stange and Hsiau-Yue Wang leg.; collected as larva, emerged 4 Jul. 1998; FSCA 00091129 .

Paratypes TAIWAN – Miaoli County • 1 ♂, 1 ♀ (2 larvae reared to adults); same data as for holotype; NTM 3620- 001 , 3620-003 . – Pingtung County • 1 ♂; Hengchun Township, Fengchuisha Beach ( Feiha-Tre-Sha Area, Kenting Nat’l Park ); 21°56′55.7″ N, 120°50′11.6″ E; 20 Apr. 1998; Robert A. Miller, Lionel A. Stange and Hsiau-Yue Wang leg.; on beach; TAMU ENTO X0405012 . – Taitung County • 1 ♂ (larva reared to adult); Donghe Township, Donghe ( Dungha ); 22°58′43.6″ N, 121°18′12.2″ E; 18 Apr. 1998; Robert A. Miller, Lionel A. Stange and Hsiau-Yue Wang leg.; NTM 3620-002 • 1 ♂ (larva reared to adult); same data as for preceding; TAMU X0405662 .

Additional material

TAIWAN – Hsinchu County • 1 ♂ (larva reared to adult); Hengshan Township, Hengshan Street Wood Factory ; 26 Nov. 2019; Jia-Wei Chuang leg.; collected in wood dust; molting failed, preserved in alcohol; NTU • 1 ♀ (larva reared to adult); same data as for preceding NMNS . – Kaohsiung City • 1 ♂ (larva reared to adult); Jiaxian District, Baiyun Mountain ; 27 Jan. 2021; Yu-Hsiu Lin leg.; molting failed, preserved in alcohol; NTU • 2 ♂♂, 2 ♀♀ (4 larvae reared to adults); Yanchao District, Jinshan Temple ; 22°48′19.01″ N, 120°23′29.18″ E; 13 Feb. 2021; Hsuan-Pu Chen leg.; preserved in alcohol; NTU • 4 ♂♂, 2 ♀♀ (6 larvae reared to adults); Qijing District, Qijing Beach ; 16 Nov. 2019; Yu-Hsiu Lin leg.; 4 specs preserved in alcohol; NTU • 1 ♂, 4 ♀♀ (5 larvae reared to adults); Meinong District, Shuangxi Arboretum Trail ; 29 Jan. 2021; Yu-Hsiu Lin leg.; preserved in alcohol; NTU . – Kinmen County • 1 ♂; Jincheng Township, Tongan Wharf ; 23 May 2020; Kai-Ti Lin leg.; preserved in alcohol; NTU . – Miaoli County • 1 ♂ (larva reared to adult); Zhunan Township, Qiding Seaside Park ; 8 Nov. 2019; Yu-Hsiu Lin leg.; preserved in alcohol; NTU • 1 ♂ (larva reared to adult); Zaoqiao Township, Shangrila Paradise Amusement Park ; 23 Sep. 2017; Yu-Jen Tsao leg.; NTU • 1 ♂, 1 ♀ (2 larvae reared to adults); same data as for preceding; 12 Jan. 2018; Yu-Jen Tsao leg.; NTU • 2 ♂♂ (2 larvae reared to adults); same data as for preceding; 3 Mar. 2018; Yu-Jen Tsao leg.; 1 spec. preserved in alcohol; NTU • 1 ♀ (larva reared to adult); same data as for preceding; 5 May 2018; Yu-Jen Tsao leg.; NTU • 1 ♀ (larva reared to adult); same data as for preceding; 9 Jun. 2018; NTU • 1 ♂ (larva reared to adult); same data as for preceding; 7 Jul. 2018; Yu-Jen Tsao leg.; NTU • 1 ♂ (larva reared to adult); same data as for preceding; 4 Aug. 2018; Yu-Jen Tsao leg.; NTU • 1 ♂ (larva reared to adult); same data as for preceding; 1 Sep. 2018; Yu-Jen Tsao leg.; NTU • 1 ♂ (larva reared to adult); same data as for preceding; 6 Oct. 2018; Yu-Jen Tsao leg.; NTU • 1 ♂, 3 ♀♀ (4 larvae reared to adults); same data as for preceding; 4 Nov. 2018; Yu-Jen Tsao leg.; NTU • 4 ♂♂, 4 ♀♀ (8 larvae reared to adults); same data as for preceding; 1 Dec. 2018; Yu-Jen Tsao and Yu-Hsiu Lin leg.; NTU • 2 ♂♂, 1 ♀ (3 larvae reared to adults); same data as for preceding; 12 Jan. 2019; Yu-Jen Tsao leg.; NTU • 2 ♂♂ (2 larvae reared to adults); same data as for preceding; 6 Jul. 2019; Yu-Jen Tsao leg.; 1 spec. preserved in alcohol; NTU • 1 ♂ (larva reared to adult); same data as for preceding; 17 Aug. 2019; Yu-Jen Tsao leg.; NTU • 1 ♂, 1 ♀; same data as for holotype; TAMU X0068719 , X0068674 . – New Taipei City • 1 ♂, 1 ♀ (2 larvae reared to adults); Gongliao District, Fulong Seaside Park ; 7 Jun. 2019; Yu-Hsiu Lin leg.; 1 spec. preserved in alcohol; NTU • 1 ♂; Jinshan District, Jinshan ; 14 Oct. 1989; Wen-Jer Wu leg.; NTU • 2 ♀♀ (2 larvae reared to adults); Shimeng District, Laomei ; 4 Aug. 2019; Yu-Hsiu Lin leg.; 1 spec. preserved in alcohol; NTU • 3 ♀♀ (3 larvae reared to adults); Bali District, Laoqiankeng Road ; 30 Oct. 2019; Yu-Hsiu Lin leg.; preserved in alcohol; NTU • 1 ♂ (larva reared to adult); Linkou District, Linkou Canyon ; 8 Nov. 2019; Yu-Hsiu Lin leg.; preserved in alcohol; NTU • 1 ♂, 3 ♀♀ (4 larvae reared to adults); same data as for preceding; 7 Nov. 2020; Yu-Hsiu Lin, Bin-Hong Ho and Yun Ho leg.; 3 specs preserved in alcohol; NTU • 1 ♀ (larva reared to adult); Gongliao District, Longmeng Bridge ; 15 Dec. 2019; Yu-Hsiu Lin leg.; NTU • 2 ♂♂ (2 larvae reared to adults); Gongliao District, Longmeng Camping Ground ; 15 Dec. 2019; preserved in alcohol; NTU • 1 ♂ (larva reared to adult); Tamsui District, Shalun Seaside Resort ; 4 Jul. 2018; Yu-Hsiu Lin leg.; NTU • 2 ♂♂, 4 ♀♀ (6 larvae reared to adults); same data as for preceding; 1 Jun. 2019; Yu-Jen Tsao leg.; 3 specs preserved in alcohol; NTU • 4 ♂♂, 2 ♀♀ (5 larvae reared to adults); same data as for preceding; 3 Sep. 2019; Yu-Hsiu Lin leg.; 4 specs preserved in alcohol; NTU • 2 ♂♂, 3 ♀♀ (5 larvae reared to adults); Jinshan District, Shitoushan Park ; 21 Dec. 2020; Yu-Hsiu Lin leg.; 4 specs preserved in alcohol; NTU • 2 ♂♂ (2 larvae reared to adults); Bali District, Wazihwei Beach ; 11 Sep. 2019; Yu-Hsiu Lin leg.; 2 specs preserved in alcohol; NTU . – Penghu County • 2 ♂♂, 2 ♀♀ (4 larvae reared to adults); Huxi Township, Aimen Beach ; 16 Jan. 2020; Yu-Hsiu Lin leg.; preserved in alcohol; NTU • 2 ♀♀ (2 larvae reared to adults); Baisha Township, Houliao Beach ; 13 Jan. 2020; Yu-Hsiu Lin leg.; 1 spec. preserved in alcohol; NTU • 1 ♂, 1 ♀ (2 larvae reared to adults); Magong City, Shanshui Beach; 16 Jan. 2020; Yu-Hsiu Lin leg.; preserved in alcohol; NTU . – Pingtung County • 1 ♀ (larva reared to adult); Checheng Township, Baoli Forest Area ; 29 Jan. 2021; Yu-Hsiu Lin leg.; preserved in alcohol; NTU • 1 ♂ (cocoon reared to adult); Checheng Township, Baoli River ; 11 Feb. 2019; Kai-Wei Chan leg.; NTU • 1 ♀ (larva reared to adult); Hengchun Township, Houbihu Beach ; 4 Feb. 2020; Yu-Hsiu Lin leg.; preserved in alcohol; NTU • 1 ♂ (larva reared to adult); Hengchun Township, Kenting National Forest Recreation Area ; 30 Jan. 2021; Yu-Hsiu Lin leg.; preserved in alcohol; NTU • 1 ♂ (larva reared to adult); Hengchun Township, South Bay ; 3 Feb. 2020; Yu-Hsiu Lin leg.; preserved in alcohol; NTU . – Taichung City • 1 ♀; Beitun District, Dakeng Trail ; 26 Nov. 2017; Yu-Ching Huang leg.; by hand; NCHU • 1 ♂, 2 ♀♀ (1 cocoon, 2 larvae reared to adults); same data as for preceding; 24 Jun. 2020; Yu-Hsiu Lin leg.; 2 specs preserved in alcohol; NTU . – Tainan City • 1 ♀; Xinhua District, NCHU Hsinhua (Xinhua) Forest Station ; 11 Oct. 1984; J.T. Yang leg.; NCHU . – Taoyuan City • 1 ♂ (larva reared to adult); Guanyin District, Caota Sand Dunes ; 8 Nov. 2019; Yu-Hsiu Lin leg.; NTU • 3 ♀♀ (3 larvae reared to adults); Xinwu District, Yongan Seaside Park ; 8 Nov. 2019; Yu-Hsiu Lin leg.; preserved in alcohol; NTU .

Re-description of the adult

MEASUREMENTS (♂ n =11, ♀ n = 12). Body length: ♂ 25.9–33.2 mm, ♀ 26.5–31.1 mm; forewing: length ♂ 27.4–35.1 mm, ♀ 28.3–33.4 mm; width ♂ 7.1–9.1 mm, ♀ 7.3–9.0 mm; width/length ratio ♂ 0.2660, ♀ 0.2604; hindwing: length ♂ 28.2–37.1 mm, ♀ 29.0– 34.3 mm; width ♂ 6.0– 7.6 mm, ♀ 6.2– 7.8 mm; width/length ratio ♂ 0.2151, ♀ 0.2185.

HEAD ( Fig. 11A–B ). Vertex strongly raised, rounded, shiny yellow, 4 shiny black spots along anterior margin and 4 shiny black spots along posterior margins, with sparse short black hairs; occiput pale yellow, with a pair of black spots in middle and a pair of pale brown spots on lateral side. Frons shiny black dorsally, whitish-yellow ventrally, with a pair of triangular dark brown near middle, covered with sparse short hyaline hairs; gena whitish-yellow, with a whitish-yellow line along ocular rim; clypeus whitish-yellow with a pair of dark brown spots, with sparse hyaline hairs. Antenna blackish-brown, short, with slightly defined club, covered with short dark hairs; scape whitish-yellow with a ring of black band; pedicel blackish-brown; flagellum comprising approximately 43 flagellomeres. Mouthparts yellow, labrum yellow, with several hyaline hairs; maxillary palps yellow, labial palps whitish-yellow, 3 rd palpomere darker, fusiform, tapering to acute apex, with brown round palpimacula on apical ⅓; submentum with long dark hairs.

THORAX ( Fig. 11B ). Pronotum broad, approximately as long as wide, mostly blackish-brown, with a whitish-yellow median stripe on anterior half, lateral side with whitish-yellow stripe, lateral margin blackish-brown, membrane with a pair of dark brown markings, with hyaline hairs and long dark hairs. Cervical sclerites whitish-yellow with dark brown markings. Mesonotum dark brown, with a U-shaped whitish band with sparse hyaline hairs; mesoscutum with a pair of white spots. Metanotum dark brown with two pairs of whitish-yellow spots, covered with sparse hyaline hairs. Meso- and metapleuron whitish-yellow with a medial dark brown stripe, moderately covered with long hyaline hairs.

LEGS. Whitish-yellow, short. Coxae whitish-yellow, moderately covered with long hyaline hairs. Femora moderately covered with short dark hairs, mixed with sparse long black setae; fore femur whitish-yellow, slightly brownish on posterior surface; mid- and hind femora dark brown on distal half of anterior surface; femoral sense hair length ½ to ⅔ of femur length on fore and mid legs, absent on hind leg. Tibiae moderately covered with short dark hairs, mixed with sparse long black setae; fore tibia dark brown on anterior surface; mid tibia brownish-yellow, darker on posterior surface. Tibial spurs reddish-brown, short, slender, almost straight, approximately as long as tarsomere 1 (slightly shorter on hind leg). Tarsi brownish-yellow, sparsely covered with short dark hairs dorsally, short black setae ventrally; tarsomere 1 approximately as long as combined length of tarsomeres 2–4; tarsomere 5 approximately as long as combined length of tarsomeres 1–4. Pretarsal claws reddish-brown, short, simple, curved, approximately as long as tibial spurs.

WINGS ( Fig. 11C ). Without markings, membrane with metabolic colorations. Forewings subacute at apex; veins and crossveins mostly brown, Sc finely alternating brown and pale yellow; costal area with interconnected crossveins from apical ⅓ to stigma, distal crossveins often branched; presectoral area with 7–10 crossveins and 0–6 irregular cells; RP arising almost opposite or slightly beyond CuA fork, with 26–39 crossveins from origin of RP to hypostigmatic cell, seldom with an extra row of cell under hypostigmatic cell; CuP supporting 1 cell before fusing with 1A; 3A mostly fused with 2A; hypostigmatic cell long; pterostigma pale white; anterior Banksian line absent, posterior Banksian line distinct. Hindwings slightly longer and narrower than forewings; acute at apex; presectoral area with 4–5 crossveins and 0–1 irregular cells; RP arising almost opposite or slightly beyond MP fork, at origin runs equidistant to RA and MA, with 26–37 crossveins from origin of RP to hypostigmatic cell; pterostigma pale white; anterior Banksian line absent, posterior Banksian line distinct; male with pilula axillaris.

ABDOMEN ( Fig. 1D ). Shorter than hindwing, tergites brown, sternite whitish-yellow, densely covered with short dark hairs dorsally and laterally, hyaline hairs ventrally.

FEMALE TERMINALIA ( Fig. 12A–B ). Tergite VIII slightly wider than tergite IX. Tergite IX narrow, rectangular in lateral view. Ectoproct semicircular in lateral view, with long, black fossorial bristles on ventral half. Lateral gonapophyses semicircular in lateral view, smaller than ectoproct, with long, black fossorial bristles on posterior side and long, thin, black setae on ventral side. Posterior gonapophyses long, slender, with long, black setae. Anterior gonapophyses short, about half length of posterior gonapophyses, slightly separated, with long, black setae. Pregenital plate absent.

MALE GENITALIA ( Figs 12C–D , 13 ). Ectoproct parallelogram in lateral view, dorsal margin as long as ventral margin, covered with short pale brown hair, ventral half with long black setae. Sternite IX almost as long as combined length of tergite IX and ectoproct, tapered in ventral view, with long black setae posteriorly. Gonarcus narrow, arched, long, arms curved ventral-posteriorly in lateral view. Mediuncus weakly sclerotized, two pale brown arches in caudal view, dorsal one longer. Parameres well sclerotized, separated, with short black setae in between, hooked in lateral view.

Distribution

Taiwan (widespread, also on associated islands of Penghu and Kinmen) ( Fig. 31D ).

Biology

From the collecting and emergence date of the examined specimens, the adults appear from late March to November. The larvae can be observed from the coastal wind-break forests to low-elevation forests ( Lin et al. 2021).

Remarks

This is a dominant species in Taiwan, the overall markings on the head and thorax make this species easy to identify ( Fig. 11A–B ). This species is similar to Myrmeleon coalitus Yang, 1999 from southeastern China in overall appearance and the species status of whether M. littoralis is a junior synonym of M. coalitus requires further confirmation ( Yang 1999; Wang et al. 2018).

Figures

Fig. 1. Adult habitus of species of Myrmeleontini Latreille, 1802 of Taiwan, lateral view. A. Baliga asakurae (Okamoto, 1910), ♀ (NTU). B. B. brunneipennis (Esben-Petersen, 1913), ♀ (NTU). C. Myrmeleon tenuipennis Rambur, 1842, ♀ (NTU). D. M. littoralis Miller & Stange, 1999, ♀ (NTU). E. M. wangi Miller & Stange, 1999, ♂ (NTU). F. M. heppneri Miller & Stange, 1999, ♂ (NTU). G. M. persimilis Miller & Stange, 1999, ♂ (NTU). H. M. punctinervis Banks, 1937, ♀ (NTU). I. M. taiwanensis Miller & Stange, 1999, ♂ (NTU). Scale bars = 10.0 mm.

Fig. 11. Myrmeleon littoralis Miller & Stange, 1999 (NTU). A. Head, frontal view. B. Head and thorax, dorsal habitus. C. Wings.Abbreviations: A = anal veins; C = costa; Cu = cubitus; CuA = cubitus anterior; CuP = cubitus posterior; MA = media anterior; MP = media posterior; pB = posterior Banksian line; RA= radius anterior; RP = radius posterior; Sc = subcosta. Scale bars: A–B = 1.0 mm; C = 10.0 mm.

Fig. 12. Myrmeleon littoralis Miller & Stange, 1999(NTU). A. Female terminalia, lateral view. B. Same, ventral view. C. Male terminalia, lateral view. D. Same, ventral view. Abbreviations: ag = anterior gonapophysis; ect = ectoproct; lg = lateral gonapophysis; pg = posterior gonapophysis; S = sternites; T = tergites. Scale bars = 1.0 mm.

Fig. 13. Myrmeleon littoralis Miller & Stange, 1999, male genitalia (NTU). A. Lateral view. B. Ventral view. C. Caudal view. Abbreviations: gon = gonarcus; med = mediuncus; par = parameres. Scale bar = 0.5 mm.

Fig. 31. Distribution of Myrmeleontini Latreille, 1802 from Taiwan and adjacent islands. A. Baliga asakurae (Okamoto, 1910). B. B. brunneipennis (Esben-Petersen, 1913). C. Myrmeleon tenuipennis Rambur, 1999.D. M. littoralis Miller & Stange, 1999.E. M. wangi Miller & Stange, 1999.F. M. heppneri Miller & Stange, 1999. G. M. persimilis Miller & Stange, 1999. H. M. punctinervis Banks, 1937. I. M. taiwanensis Miller & Stange, 1999.