Myrmeleon formicarius Linnaeus, 1767

Kim, Jiseung, Ahn, Neung-Ho & Kim, Sora, 2025, A taxonomic review of the family Myrmeleontidae Latreille (Neuroptera, Myrmeleontiformia) from the Korean peninsula, highlighting the conservation value of this family, ZooKeys 1262, pp. 97-174 : 97-174

Myrmeleon formicarius Linnaeus, 1767

Figs 11 , 12 , 35 E , 36 D , 37 B

Myrmeleon formicarius Linnaenus, 1767: 914 . Type locality: Europe.

Hemerobius formicalynx Linnaeus, 1758: 550. Type locality: Africa.

Myrmeleon neutrus Fischer von Waldheim, 1822: 51. Type locality: Russia: Siberia, Nerchinsk.

Myrmeleon innotatus Rambur, 1842: 406. Type locality: Hungary.

Myrmeleon nigrivenosus Okamoto, 1905: 116. Type locality: Japan: near Sapporo.

Myrmeleon formicarius formicarius Linnaeus, 1767: Steinmann 1963: 216.

Myrmeleon formicarius nigrilabrus Steinmann, 1963: 216. Type locality: Hungary: Vértes.

Specimens examined.

[ JBNU] • 1 ♀ (reared from larva), Changwon-ri , Nam-myeon, Yeongwol-gun, Gangwon-do, Korea, 25. VI. 2023, J. S. Kim ; • 1 ♂, Palmi-ri , Sindong-myeon, Chuncheon-si, Gangwon-do, Korea, 14. V. 2024, J. S. Kim ; • 1 ♂ 1 ♀, Changwon-ri , Nam-myeon, Yeongwol-gun, Gangwon-do, Korea, 18. V. 2024, J. S. Kim ; • 1 ♀, Changwon-ri , Nam-myeon, Yeongwol-gun, Gangwon-do, Korea, 12. VI. 2024, J. S. Kim ; • 1 ♀, Gilgok-ri , Maehwa-myeon, Uljin-gun, Gyeongsangbuk-do, Korea, 21. VI. 2024, Y. T. Jang ; 1 larva (3 rd instar), Yulji-ri , Susan-myeon, Jecheon-si, Chungcheongbuk-do, 24. VI. 2023 , 1 larva (3 rd instar), Changwon-ri , Nam-myeon, Yeongwol-gun, Gangwon-do, Korea, 25. VI. 2023, J. S. Kim ; • 2 larvae (3 rd instar), Changwon-ri , Nam-myeon, Yeongwol-gun, Gangwon-do, Korea, 12. VI. 2024, J. S. Kim .

Diagnosis.

Compared to other species in the genus Myrmeleon , M. formicarius has the morphological characteristics of an indistinct posterior Banksian line in the forewing, the femora being approximately half reddish orange, a mostly pale yellow MA in both the forewings and hindwings, and the pilula axillaris is absent. Larvae of M. formicarius have some dark markings on the hind coxa. Abdominal sternite IX with four short digging setae and two short rastra each with four digging setae.

Description.

Male, adult. Head (Fig. 11 B, C ). Vertex wide, strongly raised, black. Frons black, with short hyaline hairs; clypeus yellow, with black marking extending from frons to ventral 4 / 5. Antenna black, short, with slightly defined club, covered with short black hairs; flagellum comprising ~ 35 flagellomeres. Mouthparts dark brown; labrum dark brown, with several brown hairs; maxillary palpus dark brown; labial palpus dark brown, spindle-shaped.

Thorax (Fig. 11 B ). Pronotum broad, length shorter than width, dark brown, with yellow anterior corners, with hyaline hairs and long lateral black hairs. Mesonotum and metanotum dark brown; with long yellowish white hairs.

Legs. Coxae dark brown, moderately covered with long yellowish white hairs. Femora reddish orange; dark brown on distal 1 / 2; moderately covered with black setae. Tibiae dark brown; moderately covered with black setae. Tibial spurs reddish brown, short, almost straight, approximately as long as length of Ta 1. Tarsi dark brown, Tarsomere 5 shorter than combined lengths of tarsomeres 1–4; claws reddish brown.

Wings (Fig. 11 A ). Without marking. Forewings veins and crossveins dark brown and pale yellow; presectoral area with 10–13 crossveins; RP arising beyond CuA fork; CuP supporting one cell before fusing with 1 A; 3 A fused with 2 A; pterostigma yellowish white; anterior Banksian line indistinct, posterior Banksian line indistinct. Hindwing shorter and narrower than forewing; presectoral area with 5–7 crossveins; RP arising beyond MP fork; pterostigma yellowish white; anterior Banksian line indistinct, posterior Banksian line indistinct; male without pilula axillaris.

Abdomen (Fig. 11 A ). Shorter than hindwing, dark brown, densely covered with short black hairs and hyaline hairs.

Genitalia (Fig. 11 D, E, H – K ). Ectoproct semicircular, covered with long black setae. Sternite IX narrow, covered with long black setae. Gonarcus dark brown, arched, with long lateral arms. Mediuncus lightly sclerotized, dark brown, strongly hooked in lateral view. Parameres well sclerotized, black, rectangular in ventral view.

Size. BL: 29.9–31.1 mm; FWL: 35.1–36.0 mm; HWL: 32.3–33.7 mm.

Female, adult. Except terminalia, generally similar to male. Terminalia (Fig. 11 F, G ): tergite VIII wider than tergite IX; tergite IX narrow, semicircular in lateral view; ectoproct semicircular in lateral view; lateral gonapophyses semicircular in lateral view, smaller than ectoproct; posterior gonapophyses long, with long black setae; anterior gonapophyses small, with long black setae; pregenital plate distinct, rectangular, presented on posterior margin of sternite VII.

Size. BL: 29.3–33.1 mm; FWL: 36.3–39.3 mm; HWL: 33.4–36.8 mm.

Larva, 3 rd instar. General color reddish brown, with dark brown markings (Fig. 12 A – C ). Head triangular, longer than wide, with an anterior large dark marking and a V-shaped dark brown marking on dorsal side; with two pairs of dark brown spots on ventral side; with a pair of dark brown spots in lateral side; mandibles reddish brown; interdental mandibular setae (6) (2–4) (2–3) (1); external setae long (Fig. 12 D, E ). Hind coxa with some dark markings (Fig. 12 B, C ). Abdominal sternite VIII with sparse black setae. Abdominal sternite IX with four short digging setae in front of rastra; a paired rastra each with four digging setae (Fig. 12 F ).

Size. BL: 9.5 mm; HL: 2.6 mm, HW: 2.2 mm, ML: 2.9 mm.

Biological notes.

Myrmeleon formicarius is distributed locally in Gangwon-do, Chungcheongbuk-do, and Gyeongsangbuk-do in South Korea (Fig. 37 B ), primarily observed around grasslands environments such as logged areas and cemeteries. Adults emerge earlier (from May) than those of other species in South Korea. Larvae are pit builders, collected from dry, fine soil in open grassland environments or on cut slopes beside trails (Fig. 36 D ).

Distribution.

Korea, Japan, China, Russia, Tajikistan, Kyrgyzstan, Kazakhstan, Iran, Armenia, Turkey, Egypt, Europe ( Sekimoto 2014; Yang et al. 2023).

Remarks.

Myrmeleon formicarius is is widely distributed in the Palaearctic Region; Okamoto (1926) first reported this species from Korea. However, Kuwayama (1959) confirmed only Grocus bore Tjeder, 1941 from Korea and noted that he could not confirm any Korean specimens of M. formicarius . In this study, we confirm the presence of M. formicarius in Korea and report it with a detailed description and illustrations.

Figures

Figure 11. Myrmeleon formicarius (Linnaeus, 1758), adult. A. Dorsal habitus, male; B. Head, frontal view; C. Head and thorax, dorsal view; D, E. Male terminalia: D. Lateral view; E. Ventral view; F, G. Female terminalia: F. Lateral view; G. Ventral view; H – K. Male genitalia: H. Dorsal view; I. Ventral view; J. Lateral view; K. Caudal view.

Figure 12. Myrmeleon formicarius (Linnaeus, 1758), third instar larva. A – C. Habitus: A. Dorsal view; B. Ventral view; C. Lateral view; D, E. Head: D. Dorsal view; E. Ventral view; F. Abdominal sternite IX.

Figure 35. Living third instar larvae. A. Synclisis japonica; B. Baliga micans; C. Euroleon coreanus; D. Myrmeleon bore; E. Myrmeleon formicarius; F. Myrmeleon immanis; G. Nepsalus jezoensis; H. Distoleon littoralis; I. Ascalohybris subjacens; J. Libelloides sibiricus.

Figure 36. Habitats of the Myrmeleontidae larvae, with arrows indicating the positions where the larvae were collected. A. Under a dead tree trunk (Baliga micans); B. Calcareous grassland in limestone area (Euroleon coreanus); C. Sandy riverbank (Myrmeleon bore); D. Cut slope beside trail (Myrmeleon formicarius); E. Foredune (Myrmeleon immanis); F. Rock wall covered with lichen (Nepsalus jezoensis); G. Natural coastal dune (Synclisis japonica and Distoleon littoralis); H. Rocky hill (Ascalohybris subjacens and Libelloides sibiricus).

Figure 37. Distribution maps. A. Synclisis japonica and Baliga micans; B. Genus Myrmeleon (Myrmeleon bore, Myrmeleon fomicarius, and Myrmeleon immanis); C. Dendroleon pupillaris and Nepsalus jezoensis; D. Genus Distoleon (Distoleon littoralis and Distoleon nigricans); E. Genus Paraglenurus (Paraglenurus albiventris, Paraglenurus japonicus, and Paraglenurus melanostictus); F. Euroleon coreanus and Deutoleon lineatus lineatus; H. Ascalohybris subjacens and Libelloides sibiricus.