Myrmeleon taiwanensis Miller & Stange, 1999

Figs 1I, 26–28

Myrmeleon taiwanensis Miller & Stange in Miller et al., 1999: 69. Type locality: Taiwan (Pingtung).

Myrmeleon taiwanensis – Stange et al. 2003: 123. — Sekimoto 2014: 21. — Wang et al. 2018: 107.

Myrmeleon (Myrmeleon) taiwanensis – Stange 2004: 336. — Lin et al. 2019: 140.

Material examined

Holotype TAIWAN • ♂ (photos examined); Pingtung County, 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.; collected as larva, emerged 24 Jun. 1998; on beach; FSCA 00091192.

Paratypes TAIWAN – Pingtung County • 3 ♂♂, 1 ♀ (4 larvae reared to adults); same data as for holotype; NTM 3624-001 to 3624-003 • 1 ♀ (larva reared to adult); Checheng Township, Haikou Desert; 22°05′10.4″ N, 120°42′15.4″ E; 22 Apr. 1998; Robert A. Miller, Lionel A. Stange and Hsiau-Yue Wang leg.; NTM 3624-004 .

Additional material

TAIWAN – Pingtung County • 1 ♂; Hengchun Township, “Kenting Bot. Garden” [now Kenting National Forest Recreation Area]; 260 m a.s.l.; 22–25 Jul. 1980; D.R. Davis leg.; subtropical forest; USNM • 2 ♂♂, 2 ♀♀ (4 larvae reared to adults); Hengchun Township, Baisha Beach ( White Sand Bay); 4 Feb. 2020; Yu-Hsiu Lin leg.; 3 specs preserved in alcohol; NTU • 2 ♂♂, 1 ♀ (3 larvae reared to adults); Hengchun Township, Dawan Beach; 3 Feb. 2020; Yu-Hsiu Lin leg.; 2 specs preserved in alcohol; NTU • 2 ♂♂, 2 ♀♀ (4 larvae reared to adults); Hengchun Township, Fengchuisha Beach; 3 Feb. 2020; Yu-Hsiu Lin leg.; 3 specs preserved in alcohol; NTU • 1 ♂, 2 ♀♀ (3 larvae reared to adults); Manzhou Township, Gangkou beach; 3 Feb. 2020; Yu-Hsiu Lin leg.; 2 specs preserved in alcohol; NTU • 1 ♂ (larva reared to adult); Checheng Township, Haikou Desert; 31 Jan. 2021; Yu-Hsiu Lin leg.; NTU • 2 ♂♂ (2 larvae reared to adults); Manzhou Township, Jiupeng Desert; 4 Feb. 2020; Yu-Hsiu Lin leg.; preserved in alcohol; NTU • 2 ♂♂ (2 larvae reared to adults); Hengchun Township, Little Bay Beach; 31 Jan. 2021; Yu-Hsiu Lin leg.; 1 spec. preserved in alcohol; NTU • 1 ♂ (larva reared to adult); Hengchun Township, Shuiwaku; 7 Feb. 2021; Yu-Hsiu Lin, Bin-Hong Ho and Yun Ho leg.; preserved in alcohol; NTU . – Taitung County • 1 ♀ (larva reared to adult); Taitung City, Haibin Park; 6 Feb. 2021; Yu-Hsiu Lin, Bin-Hong Ho and Yun Ho leg.; preserved in alcohol; NTU • 2 ♀♀ (2 larvae reared to adults); Taimali Township, Jinlun Beach; 6 Feb. 2021; Yu-Hsiu Lin, Bin-Hong Ho and Yun Ho leg.; 1 spec. preserved in alcohol; NTU • 2 ♀♀ (2 larvae reared to adults); Chenggong Township, Sanxiantai; 5 Feb. 2021; Yu-Hsiu Lin, Bin-Hong Ho and Yun Ho leg.; preserved in alcohol; NTU • 3 ♀♀ (3 larvae reared to adults); Lanyu Township, Yeyin Beach; 15–16 Jul. 2020; Yu-Hsiu Lin leg.; 2 specs preserved in alcohol; NTU • 1 ♂ (larva reared to adult); Lanyu Township, Yeyou River mouth; 17 Jul. 2020; Yu-Hsiu Lin leg.; preserved in alcohol; NTU .

Re-description of the adult

MEASUREMENTS (♂ n =10, ♀ n = 9). Body length: ♂ 22.8–27.1 mm, ♀ 23.3–26.2 mm; forewing: length ♂ 22.5–27.4 mm, ♀ 25.1–28.3 mm; width ♂ 5.3–6.5 mm, ♀ 5.8–6.5 mm; width/length ratio ♂ 0.2338, ♀ 0.2324; hindwing: length ♂ 21.4–25.3 mm, ♀ 22.7–25.9 mm; width ♂ 4.4–5.6 mm, ♀ 4.6–5.7 mm; width/length ratio ♂ 0.2115, ♀ 0.2116.

HEAD (Fig. 26A–B). Vertex strongly raised, rounded, black, 4 shiny black spots along anterior margin and 4 shiny black spots along posterior margins, with sparse short black hairs; occiput dark brown, paler in middle. Frons shiny black, covered with sparse short hyaline hairs; gena whitish-yellow, with an incomplete white line along ocular rim; clypeus whitish-yellow with a pair of dark brown spots (sometimes pale), with sparse hyaline hairs. Antenna brown, short, with slightly defined club, covered with short dark hairs; scape dark brown with a ring of white band at base; pedicel dark brown with a ring of white band at base; flagellum comprising approximately 30 flagellomeres. Mouthparts yellow, labrum yellow, with several hyaline hairs; maxillary palps dark brown, whitish-yellow between each palpomere, labial palps dark brown, 3 rd palpomere black, fusiform, tapering to acute apex, with brown round palpimacula on apical ⅓; submentum with long dark hairs.

THORAX (Fig. 26B). Pronotum broad, shorter than wide, dark brown, anterior margin with whitish-yellow bands on lateral side, membrane whitish-yellow, with triangular brown marking in middle, with hyaline hairs and long dark hairs. Cervical sclerites dark brown. Mesonotum dark brown, with sparse hyaline hairs; mesoscutum dark brown. Metanotum dark brown, covered with sparse hyaline hairs. Meso- and metapleuron dark brown, moderately covered with long hyaline hairs.

LEGS. Whitish-yellow, short. Coxae dark brown, fore coxae with yellow markings, moderately covered with long hyaline hairs. Femora moderately covered with short dark hairs, mixed with sparse long black setae; all femora whitish-yellow, dark brown on distal half; femoral sense hair length about ½ 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; mid- and hind tibia whitish-yellow, dark brown on ventral surface. Tibial spurs reddish-brown, short, slender, almost straight, slightly longer than tarsomere 1 (approximately as long on hind leg). Tarsi dark brown, tarsomere 1 whitish-yellow on dorsal surface, sparsely covered with short dark hairs dorsally, short black setae ventrally; tarsomere 1 shorter than 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, shorter than tibial spurs.

WINGS (Fig. 26C). Without markings, hyaline. Forewings acute at apex; veins and crossveins mostly pale brown, Sc, RA and CuA finely alternating brown and pale yellow; costal area without interconnected crossveins, distal crossveins often branched; presectoral area with 8–10 crossveins and 0 irregular cells; RP arising slightly beyond CuA fork, with 12–16 crossveins from origin of RP to hypostigmatic cell; CuP supporting 1 cell before fusing with 1A; 3A mostly fused with 2A; hypostigmatic cell long; pterostigma pale white, slightly visible; anterior Banksian line absent, posterior Banksian line distinct. Hindwings slightly shorter and narrower than forewings; acute at apex; presectoral area with 5 crossveins and 0 irregular cells; RP arising beyond MP fork, at origin runs closer to MA, with 10–12 crossveins from origin of RP to hypostigmatic cell; hypostigmatic cell longer than forewing; pterostigma pale white, slightly visible; anterior Banksian line absent, posterior Banksian line slightly distinct; male with dark brown pilula axillaris.

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

FEMALE TERMINALIA (Fig. 27A–B). Tergite VIII at least 2 times as wide as 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 slightly lobed, separated, with long, thick, black setae. Pregenital plate well sclerotized, semicircular, presented on posterior margin of sternite VII.

MALE GENITALIA (Figs 27C–D, 28). Ectoproct trapezoid in lateral view, slightly curved toward posterior, dorsal margin shorter than ventral margin, covered with short pale brown hair, ventral half with long black setae. Sternite IX shorter than combined length of tergite IX and ectoproct, tapered in ventral view, with long black setae posteriorly. Gonarcus arched, cresent-shaped in lateral view. Mediuncus well sclerotized, black, rectangular in caudal view, ventral margin with a median groove. Parameres well sclerotized, large, black, triangular in lateral view, parallelogram in caudal view, separated, with short black setae.

Distribution

Taiwan (Pingtung, Taitung, also on the associated island of Lanyu) (Fig. 31I), Japan (Iriomote Island, Ishigaki Island, Okinawa Island).

Biology

The larvae inhabit coastal environments in the southern parts of Taiwan, preferring sheltered conditions like beneath coastal vegetation (Lin et al. 2021).

Remarks

This is a medium-sized species, the overall morphology of the adult resembles M. persimilis, M. heppneri and M. punctinervis, but with narrower wings and can be recognized by the fully dark-colored vertex and thorax (Fig. 26A–C).