Scaphisoma Leach, 1815

Kim, Ye-Jun & Ahn, Kee-Jeong, 2023, Descriptions of Two New Species of Scaphisoma Leach (Coleoptera: Staphylinidae: Scaphidiinae) in Korea, The Coleopterists Bulletin 77 (4), pp. 537-541 : 537-538

Genus Scaphisoma Leach, 1815

Scaphisoma Leach 1815: 89 . Type species: Silpha agaricina Linnaeus.

KEY TO THE SPECIES OF KOREAN SCAPHISOMA

(modified from Kim and Ahn 2022)

1. Body longer than 2.0 mm ................................2

1′. Body shorter than 2.0 mm ...............................3

2. Maxillary palpomere 3 triangular; antennomere 6 longer than 4 and 5 combined .............. ................................... S. limbatum Erichson

2′. Maxillary palpomere 3 cylindrical; antennomere 6 shorter than 4 and 5 combined............ .................... S. subalpinum ussuricum Löbl

3. Elytra bicolored .................................................4

3′. Elytra unicolored...............................................6

4. Antennomere 5 longer than 3 and 4 combined ..... S. koreanum Kim and Ahn , new species

4′. Antennomere 5 as long as 3 and 4 combined ......................................................................5

5. Elytra with dark brown spot near humeral angle and dark brown band in apical one-third .............. S. sambangsanense Kim and Ahn , new species

5′. Elytra with broad yellow band near apical one-fifth.......................... S. hapiroense Löbl

6. Antennomere 4 more than 1.5 times as long as 3 .............................................................. 7

6′. Antennomere 4 less than 1.5 times as long as 3 .................................... S. rufum Achard

7. Antennomere 11 as long as 10 ...................... ........................................ S. unicolor Achard

7′. Antennomere 11 longer than 10.................... .............................................. S. portevini Pic

Scaphisoma koreanum Kim and Ahn , new species zoobank.org/ urn:lsid:zoobank.org:act:C9AB7FE4-8881-426E-9A41-E15D5268AB3C ( Figs. 1 , 4, 5, 6, 8 )

Type Specimens. Holotype: ♂, labeled as follows: “ KOREA: Jeju Prov., Seoguipo-city, Hawon-dong, Seoguipo Natural Recreation Forest , N33° 18′32.7′′ E126°27′59′′ 670 m, 30 V 2007, K.-J. Ahn, D.-H. Lee, ex fungus on log; HOLOTYPE Scaphisoma koreanum ”. Deposited in CNUIC . Paratypes: 1 ex., same data as holotype; 2 exx., KOREA, Jeju Prov., Seoguipo-city, Hawon-dong, Seoguipo Natural Recreation Forest , N33°18′32.7′′ E126°27′56.04′′, 730 m, 30 V 2007 K.-J. Ahn, D.-H. Lee, ex fungus on log; 2 exx., Seoguipo Natural Recreation Forest , N33°18′36′′ E126°28′92′′ 665m, 31 V 2007, D.-H. Lee, T.- K. Kim, ex under bark ; 1 ex., Mt. Hallasan, Dongsuak , 29 V 2003, Y.-B. Cho, ex sifting .

Other Specimens Examined. 2 exx., KOREA: Chungnam Prov., Nonsan-si Yangchon-myeon, Jungsan-ri Ssanggyesa, N36°6′33.69″ E127°13′12.48″, 24 VII 2008, Y.-H. Kim, fungus on logs; 2 exx., Daejeon- si, Dong-gu, Sechon-dong, N36°19′34.76″ E127°29′02.05″ 118 m, 8 VII 2020, J.-Y. Park, K.-J. Ahn, Y.-J. Shin, under bark; 1 ex., Gangwon Prov., Pyeongchang-gun, Cheondong-ri, Mt. Sambangsan. 13 VII–15 VIII 2001, K.-J. Ahn, S.-J. Park, C.-W. Shin, ex FIT in Pinus forest; 3 exx, Hwachungun, Hwaaksan, 11-12 IX 1998, K.-L. Kim, H.-J. Lim, K.-J. Ahn, ex FIT .

Description. Body length 1.9–2.1 mm, width 1.3 mm. Head, antenna and pronotum yellowish brown, elytra yellowish brown with reddish brown in sutural and basal region, pygidium yellowish brown, meso- and metaventrites and abdominal sternites reddish brown, legs yellowish brown but tarsi yellow. Measurement of holotype. Body 2.0 mm in length; head 0.6 mm in length (from anterior margin of labrum to the base), 0.42 mm in width; pronotum 0.8 mm in length, 1.1 mm in width; elytron 1.3 mm in length, 0.44 mm in width. Head. Finely and densely punctate; relative ratio of antennomeres 3 to 11 (4:9:12:12:13:11:14:12:13); antennomeres 7–11 expanded; antennomere 4 long, more than 2.0 times as long as 3; antennomere 6 almost as long as 7 and 8 ( Fig. 8 ). Thorax. Pronotum finely and densely punctate, width about 1.5 times as wide as long, widest near posterior margin; scutellum small and covered by protruding part of pronotum, invis- ible in dorsal view. Elytra distinctly, densely punctate, widest at basal one-fourth, sutural line rather shallow, very slightly curved outward at basal end. Hypomeron smooth, without punctures or setae. Mesoventrite smooth with sparse, fine punctures; submesocoxal area narrow, 0.04 mm long. Metaventrite punctation similar to that of mesoventrite; submetacoxal area wide, 0.1 mm long, slightly widened near lateral margin, widened significantly halfway to submetacoxal margin, as long as half length of abdominal sternite III. Legs. Protibia and mesotibia straight, metatibia curved. Abdomen. Pygidium finely and densely punctate. Sternite III with fine, dense punctures. Male. Front tarsus with setae more abundant than that of female. Aedeagus 1.16 mm in length (from the base of median lobe to apex of paramere) and width 0.5 mm in dorsal view ( Fig. 4 ), basal bulb wide and oval in dorsal view, almost as long as paramere, paramere wide and long, expanded in basal region in lateral view ( Fig. 5 ); internal sac as in Fig. 6 .

Distribution. Korea (Jeju-do Island).

Etymology. Named after the country of origin.

Remarks. This new species is similar to Scaphisoma hapiroense Löbl in antennomere ratio (antennomere 5 as long as 6, 8 shorter than 5 or 6), body length (around 2.0 mm), and basal bulb of median lobe with an oval shape, nearly circular. However, they can be distinguished by the combination of the following characters: ratio of antennomere 3 to 11 (4:7:11:11:15:10:13:13:16), bicolored elytra (yellowish brown but reddish brown in sutural and basal region), and the different form and structure of the aedeagus.

This species is also similar to Scaphisoma atronotatum Pic in the size of the median lobe and the long and wide paramere that is post-basally enlarged. However, they can be distinguished by the wider and more oval basal bulb, paramere with apically and dorsally enlarged region, and the different form of the internal sac ( Fig. 6 ).

Figures

Figs. 1–3. Habitus, left in dorsal view and right in lateral view. 1) Scaphisoma koreanum, new species, 2.0 mm;

Figs. 4–10. Male genitalia (4–7) and antennomeres 3–11 (8–10). Scaphisoma koreanum, new species: 4) Dorsal view (left) and lateral view (right); 5) Paramere, ventral view; 6) Internal sac, dorsal view (left) and lateral view (right). 7) S. sambangsanense, new species, dorsal view (left) and lateral view (right). 8) S. koreanum, new species; 9) S. sambangsanense, new species; 10) S. limbatum. Scale bars = 0.1 mm.