Nepsalus jezoensis ( Okamoto, 1910 )

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

Nepsalus jezoensis ( Okamoto, 1910)

Figs 16 , 17 , 35 G , 36 F , 37 C

Dendroleon jezoensis Okamoto, 1910: 280. Type locality: Japan: Honshu: Kanto: Tochigi: Nikko.

Glenurus jezoensis Matsumura, 1908: 41. nom. nud.

Gatzara jezoensis ( Okamoto, 1910): Miller et al. 1999: 52.

Nepsalus jezoensis ( Okamoto, 1910): Zheng et al. 2022: 17.

Specimens examined.

[ JBNU] 1 ♀, Samjung-ri , Macheon-myeon, Hamyang-gun, Gyeongsangnam-do, Korea, 17. IX. 2022, J. S. Kim ; • 1 ♀ (reared form larva), Naejang-dong , Jeongeup-si, Jeonbuk-do, Korea, 14. VII. 2023, J. S. Kim ; • 7 ♂ 2 ♀ (reared form pupa), Jungsan-ri , Sicheon-myeon, Sancheong-gun, Gyeongsangnam-do, Korea, 25. VI. 2024, J. S. Kim ; • 1 ♂, Oeseonmi-ri , Onjeong-myeon, Uljin-gun, Gyeongsangbuk-do, Korea, 13. VII. 2024, J. S. Kim ; • 1 ♀, Sa-ri , Heuksan-myeon, Sinan-gun, Jeollanam-do, Korea, 3. IX. 2024, J. S. Kim ; 1 larva (3 rd instar), Naejang-dong , Jeongeup-si, Jeonbuk-do, Korea, 14. VII. 2023, J. S. Kim ; • 3 larvae (2 nd and 3 rd instar), Wongi-ri , Gui-myeon, Wanju-gun, Jeonbuk-do, Korea, 8. III. 2025, J. S. Kim ; 1 larva (2 nd instar), Gaegok-ri , Daechi-myeon, Cheongyang-gun, Chungcheongnam-do, Korea, 15. III. 2025, J. S. Kim ; 1 larva (2 nd instar), Gwangdae-ri , Daechi-myeon, Cheongyang-gun, Chungcheongnam-do, Korea, 16. III. 2025, J. S. Kim ; 1 larva (3 rd instar), Wongi-ri , Gui-myeon, Wanju-gun, Jeonbuk-do, Korea, 29. III. 2025, J. S. Kim .

Diagnosis.

Nepsalus jezoensis is is similar to Nepsalus insularum Hayashi, Saito & Matsumoto, 2024 from southern Japan (Amamio, Okinawa, Kume, and Ishigaki islands) in general appearance. These two species can be distinguished by differences in the patterns on their wings, pronotum, and abdomen. In N. jezoensis , the forewing cubital area with an arcuate dark brown marking fused with a large brown spot, while they are not fused in N. insularum . Nepsalus insularum has wider blackish markings on the thorax, and larger dark brown markings on the abdomen. In larvae, the mandibles are equipped with five or six pseudo-teeth, and the legs are pale brown distally ( Hayashi et al. 2024).

Description.

Male, adult. Head (Fig. 16 B, C ). Vertex slightly narrow, moderately raised, yellowish white. Frons yellow, with broad dark brown band at middle; clypeus yellow, with long black hairs. Antenna dark brown, slightly long, with slightly defined club, densely covered with short black hairs; flagellum comprising ~ 35 flagellomeres. Mouthparts yellow; labrum yellow, with dark and brown hairs; maxillary palpus yellowish brown; labial palpus yellowish brown.

Thorax (Fig. 16 C ). Pronotum slender, longer than broad, yellowish white, with slender dark brown longitudinal median stripe. Mesonotum and metanotum yellowish white, with dark spot at middle.

Legs. Coxae yellow, moderately covered with long black hairs. Femora mostly dark brown; partly yellow; moderately covered with black setae. Tibiae mostly dark brown; partly yellow; densely covered with short black hairs. Tibial spurs yellowish brown, long, slight curved, approximately as long as combined lengths of tarsomeres 1 and 2. Tarsi pale brown, tarsomere 5 shorter than combined lengths of tarsomeres 1–4; claws reddish brown, opposable.

Wings (Fig. 16 A ). With brown markings. Forewings veins and crossveins mostly brown; presectoral area with 3–5 crossveins; RP arising before CuA fork; CuP supporting one or two cells before fusing with 1 A; 2 A and 3 A separate, connected by one crossvein; pterostigma white; anterior Banksian line distinct, posterior Banksian line absent. Hindwing approximately as long as forewing, narrower than forewing, with small brown markings along posterior margin; presectoral area with one crossvein; RP arising before MP fork; pterostigma white; anterior Banksian line distinct, posterior Banksian line absent; male with pilula axillaris.

Abdomen (Fig. 16 A ). Shorter than hindwing, yellowish white, moderately covered with black hairs.

Genitalia (Fig. 16 D, E, H – K ). Ectoproct rectangular, covered with long black setae. Sternite IX narrow, covered with long black setae. Gonarcus yellowish brown, arched. Mediuncus lightly sclerotized, reddish brown, strongly raised. Parameres broad, dark brown posteriorly, well sclerotized posteriorly.

Size. BL: 18.2–21.8 mm; FWL: 23.2–26.7 mm; HWL: 22.1–26.1 mm.

Female, adult. Except terminalia, generally similar to male. Pilula axillaris absent. Terminalia (Fig. 16 F, G ): tergite VIII wider than tergite IX; tergite IX narrow, rectangular in lateral view; ectoproct semicircular in lateral view; a pair of gonapophyses present below tergite IX; lateral gonapophyses semicircular in lateral view, smaller than ectoproct; posterior gonapophyses long, with long black setae; anterior gonapophyses long, with long black setae; pregenital plate distinct, small, triangular, presented on membrane below tergite VIII.

Size. BL: 20.8–23.5 mm; FWL: 25.1–30.9 mm; HWL: 24.9–30.1 mm.

Larva, 3 rd instar. General color pale brown and pale green, with dark brown markings (Fig. 17 A – C ). Head rectangular, longer than wide, with a triangular dark brown spot anteriorly and a pair of dark brown spots on dorsal side; without marking on ventral side; with a pair of dark brown spots in lateral side; mandibles yellowish brown, with five or six pseudo-teeth developed in addition to three normal teeth; external setae short (Fig. 17 D, E ). Abdominal sternite VIII with sparse black setae. Abdominal sternite IX with sparse black setae (Fig. 17 F ).

Size. BL: 7.1 mm; HL: 1.9 mm, HW: 1.7 mm, ML: 2.5 mm.

Biological notes.

Nepsalus jezoensis is a species observed mainly in mountainous topography throughout South Korea (Fig. 37 C ) where adults mainly emerge from July to September. Larvae were collected on rock walls or tree bark where lichens grow densely, and they camouflage their bodies with lichens (Fig. 36 F ). In larval habitats, empty cocoons can be easily observed.

Distribution.

Korea, Japan, Russia ( Zheng et al. 2022; Hayashi et al. 2024).

Remarks.

This species was originally classified in the genus Gatzara Navás , but it was reassigned to the genus Nepsalus Navás by Zheng et al. (2022) based on morphological and genetic analysis.

Figures

Figure 16. Nepsalus jezoensis (Okamoto, 1910), 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 17. Nepsalus jezoensis (Okamoto, 1910), 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.