Eumetopus Balfour-Browne, 1949

Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav & Jäch, Manfred A., 2021, The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1), pp. 1-34 : 24-25

Eumetopus Balfour-Browne, 1949

( Figs 2M–Q ; 3C–D, L–O ; 4A–B, D, H, L–M ; 5C, I, L ; 6S–Z ;

7A–C ; 14–15 )

Eumetopus Balfour-Browne, 1949: 13 . Type species: Sepidulum bullatum Sharp, 1875 .

Eumetopus : H*òඇඌൾඇ (1991), Jං & Jඟ*ö*ü (1998a,b), H*òඇඌൾඇ (1999), Jඟ*ö*ü A. Prokin & A. Sazhnev leg.; 4 JJ 1 ♀ with egg case (IBIW): same

(2002), Sκ*òඅൾ & Jඟ*ö*ü (2003), H*òඇඌൾඇ (2004), Fංκගඹൾκ & Rඒඇൽൾඏං*ö*ü locality, 13.iv.2019, A. Prokin lgt. (2015).

Comments. Eumetopus acutimontis was so far only known

Diagnosis. Moderately large species (body length 2.6–4.3 from Hainan Island, China. The specimens from Vietnam mm); body brown to black, partly with a metallic sheen correspond well with the drawing of the male genitalia by (especially on pronotum and elytral tubercles; Figs 14– J ං & Jඟ*ö*ü (1998a), and their external morphology agrees 15); eyes not divided completely into dorsal and ventral with the female paratype deposited in the NHMW. This portion ( Fig. 4A ); anterior oblique portion of clypeus is the first record of E. acutimontis from continental Asia divided from posterior parts by a ridge ( Fig. 4B ); lab- and from Vietnam. rum strongly narrowed posteriorly ( Fig. 2J ); mandibular Biology. All specimens were found on the wet sandy banks apex bidentate ( Figs 2M–L ); apical maxillary palpomere of the Shuoi-Ngang river, by washing out the shore sedilong, strongly asymmetrical ( Fig. 2M ); mentum slightly ment (Figs A–D); the specimens were floating at the water wider than long, with series of long setae along anterior surface when they were washed from the sandy shore. margin ( Figs 2N–O , 4D ); pronotum 0.7–0.8× as long as Adults of some Hydrophilidae , Byrrhinus sp. (Limnichiwide, hood covering head forming anterior third of its dae) and a larva of Eulichas Jakobson, 1913 ( Eulichadidae ) length; ventral surface of the hood with set of parallel were collected from the same microhabitat. For video of a ridges ( Fig. 3D ); prosternum ( Fig. 3C ) slightly elevated living specimen, see Supplementary File S1. medially, ca. 0.25× as long as procoxal cavity; procoxal cavity open posteriorly ( Fig. 3C ); elytron with scutellary Eumetopus asperatus (Champion, 1919) stria ( Fig. 15 ); elytra with tubercles on alternate intervals ( Figs 14B , 15B ) ( Fig. 15 ); mesanepisterna narrowly separated by anterior

Material examined. INDIA: UඍඍൺඋൺκΗൺඇൽ: 5 spec. ( NHMW, NMPC): portion of mesoventrite; mesoventrite posteromesally 30 km NNE Bageshwar, west of Loharket Village, 1800–1900 m, with high bulge ( Fig. 3L ); metaventrite ca. as long as 24.vi.2003, Z. Kejval & M. Trýzna lgt. mesocoxa, posteromesally with large central and a pair of

Comments. Except for the holotype, this species has not lateral smooth elevated areas ( Fig. 3L ); middle and hind

been recorded from Uttarakhand. femora with posterior spine ( Fig. 4M ); phallobase long and conical; parameres subdivided into dorsal and ventral

Eumetopus bullatus ( Sharp, 1875) lobe; median lobe thin, peg-like, without projections (Figs

( Figs 6Z , 14C , 15C ) 6V–Z); sperm pump present ( Fig. 6Y ); male sternite IX circular ( Fig. 6U ). Material examined. INDIA: MൺΗൺඋൺඌΗඍඋൺ: 4 JJ 4 ♀♀ (NHMW,

NMPC): ca. 15 km E Sawantwadi, 15°55′N 73°53′E [coordinates on

Identification. The genus was revised by Jං & Jඟ*ö*ü (1998)

original labels (15°55′N 75°53′E) are incorrect, Z. Kejval, pers. comm.], who also illustrated the male genitalia for all species riverside, 40 m, 22.v.2006, Z. Kejval lgt. known at that time. One additional species was described by Jඟ*ö*ü (2002) who provided an updated identification Comments. The species was so far only known from the key. The latest recognized species was described by holotype with the type locality ‘Indiaʼ (S*ü*ò*©ඉ 1875, Jං & Sκ*òඅൾ & Jඟ*ö*ü (2003) and compared to its closest relative. Jඟ*ö*ü 1998). This is therstfi precise record, confirming the

occurrence in India. List of species (8 described species)

Eumetopus flavidulus (Sharp, 1890)

E. acutimontis Ji & Jäch, 1998 China (Hainan; Jං & Jඟ*ö*ü 1998a), ( Figs 14D , 15D, J )

Vietnam (this paper)

E. asperatus (Champion, 1919) India: Himachal Pradesh, Uttarakhand; Material examined. INDIA: MൺΗൺඋൺඌΗඍඋൺ: 4 JJ 4 ♀♀ (NHMW, Nepal (Jං & Jඟ*ö*ü 1998a, Sκ*òඅൾ & Jඟ*ö*ü NMPC): ca. 15 km E Sawantwadi, 15°55′N 73°53′E [coordinates on

2003, Hൾ*ô*òඎൾ*© 2006b, this paper) original labels (15°55′N 75°53′E) are incorrect, Z. Kejval, pers. comm.],

E. bullatus ( Sharp, 1875) India: Maharashtra (this paper). riverside, 40 m, 22.v.2006, Z. Kejval lgt. AඇൽΗඋൺ PඋൺൽൾඌΗ: 1 J 1 ♀

E. flavidulus (Sharp, 1890) India: Andhra Pradesh, Kerala, Maha- (SLC): Vijayawada, Krishna River, 16.511°N 80.614°E, 16.ii.2014, K. rashtra, Meghalaya, Odisha; Sri Lanka Tomkovich lgt.

(Jං & Jඟ*ö*ü 1998a, this paper)

E. maindroni ( Régimbart, 1903) India: Gujarat, Maharashtra, Tamil Comments. First record for Andhra Pradesh and Maha- Nadu (RඣǤංආ*ô*ò*©ඍ 1903, Jං & Jඟ*ö*ü rashtra.

1998a, this paper)

E. schuelkei Jäch, 2002 Laos (Jඟ*ö*ü 2002) Eumetopus maindroni ( Régimbart, 1903)

E. tibialis Ji & Jäch, 1998 northern Thailand (Jං & Jඟ*ö*ü 1998a) ( Figs 14E , 15E )

E. weigeli Skale & Jäch, 2003 Nepal (Sκ*òඅൾ & Jඟ*ö*ü 2003), India: Uttarakhand (this paper). Material examined. INDIA: MൺΗൺඋൺඌΗඍඋൺ: 3 JJ 1 ♀ (NHMW): ca.

15 km E Sawantwadi, 15°55′N 73°53′E [coordinates on original labels

(15°55′N 75°53′E) are incorrect, Z. Kejval, pers. comm.], riverside,

Eumetopus acutimontis Ji & Jäch, 1998 40 m, 22.v.2006, Z. Kejval lgt. Gඎඃൺඋൺඍ: 1 J 5 ♀♀ (SLC): Junagadh,

( Figs 6S–Y , 14A , 15A, I ) Girnar Mt., 21.526°N 70.48°E, 20–31.x.2012, at light, K.Tomkovich lgt.

Material examined. VIETNAM: KΗගඇΗ Hණൺ Pඋඈඏ.: 1 J 1 ♀ with Comments. The species was so far known only from the

egg case ( IBIW): Ba Ho Waterfalls National Park, river Shuoi-Ngang, type specimens (RඣǤංආ*ô*ò*©ඍ 1903, Jං & Jඟ*ö*ü 1998a) from

12°23.131′N 109°08.052′E, 18.iv.2018, A. Prokin & A. Sazhnev leg.; 12 the Indian state of Tamil Nadu. Here we report it from

JJ 9♀♀ (2 ♀♀ with egg case) ( IBIW, NMPC): same locality, 2.v.2018, Gujarat and Maharashtra for the first time.

Figures

Fig. 2. Morphology of mouthparts and head appendages of the genera of Epimetopidae.A–I – Eupotemus Ji & Jäch, 1998: A, C, E, F, H – E. smithi sp. nov., B, D, G – E. limicola (Delève, 1967), I – E. cameroonensis sp. nov. J–Q – Eumetopus Balfour-Browne, 1949: J, L, M, N, P – E. schuelkei Jäch, 2002, Q – E. bullatus (Sharp, 1875), K, L*, O – E. sp. from Sri Lanka. R–Z, a–l – Epimetopus Lacordaire, 1854: R–W – E. mendeli Fikáček et al., 2011, X–Z, a–c – E. costaricensis Perkins, 1979, g, j – E. thermarum Schwarz & Barber, 1917, e, k – E. trogoides (Sharp, 1874), h – E. costatus group, f, i, l – E. punctipennis Perkins, 1979. Body parts:A–B, J–K, R, X, g–i – labrum; C, L, S, Y – mandibles; D, L*, e–f – mandibular apex; E, M, T, Z – maxilla; U – detail of basal part of ultimate palpomere; F–G, N–O, V, a–b, j–l – mentum and prementum; H–I, P–Q, W, c – antenna. Not to scale.

Fig. 3. Thoracic morphology of the genera of Epimetopidae. A–B, J, Q – Eupotemus smithi sp. nov.; C–D, L–O – Eumetopus schuelkei Jäch, 2002; E–F – Epimetopus mendeli Fikáček, Barclay & Perkins, 2012; G–I, P – Epimetopus costaricensis Perkins, 1979. A–I – prothorax in ventral view (B, D, F, H – detail of ventral sculpture of the pronotal hood; I – detail of closed procoxal cavity. J–L – meso- and metathorax in ventral view. M–N – elytron in ventral view (M – general view; N – detail of the ventral ridge, notice the spiny surface on inner face of the ridge (in) and on the elytral plectrum posteriorly of it (pl)). O – mesotrochanter. P–Q – details of pretarsus with the leaf-like empodial seta. Not to scale.

Fig. 4. Head and leg morphology of the genera of Epimetopidae. A–B, H, L – Eumetopus acutimontis Ji & Jäch, 1998; D, M – Eumetopus schuelkei Jäch, 2002; C, K–L, Q – Eupotemus smithi sp. nov.; F–G – Epimetopus punctipennis Perkins, 1979 (adopted from Pൾ*©κංඇඌ 2012); E, I–J, R – Epimetopus mendeli Fikáček, Barclay & Perkins, 2011; N–O – Epimetopus costaricensis Perkins, 1979. A – head in dorsolateral view (can – clypeal canthus causing the eye emargination); B–C – head in dorsal view (arrow – the ridge dividing anterior declined part of clypeus); D – mentum and maxilla; E – head in ventral view; F–G – occipital part of the head with median raised tubercle, dorsolateral view (arrows: parallel impressions corresponding to ventral ridges of pronotal hood); H–I – antenna, scapus largely omitted; J – labial palp; K – apical tibial armature, ventral view, mesothoracic leg; L – apical tibial armature and tarsus, ventral view, metathoracic leg; M – mesotibia; N–O – tarsus (N – posterior; O – anterior); P–R – metatibia, dorsal view. Not to scale.

Fig. 5. Morphology of Epimetopidae. A–B – ventral morphology: A – Eupotemus smithi sp. nov.; B – Epimetopus mendeli Fikáček, Perkins & Barclay, 2011. C–F – hind wings: C – Eumetopus schulkei Jäch, 2002; D – Eupotemus smithi sp. nov.; E – Epimetopus mendeli, adopted from Fංκගඹൾκ et al. (2011); F – Epimetopus costaricensis Perkins, 1979. G – dorsal part of the metathorax. H – scutellum. I–K – abdominal ventrites (I – Eumetopus schuelkei; J – Eupotemus smithi sp. nov.; K – Epimetopus mendeli). L–M – ovipositor (L – Eumetopus schuelkei; M – Eupotemus smithi). O – elytral punctation, slide-mounted elytra of Epimetopus costaricensis. P – female of Eumetopus acutimontis in ventral view, with the egg cases carried under the abdomen. Not to scale.

Fig. 6. Male genitalia and associated structures of Epimetopidae. A–H – Eupotemus Ji & Jäch, 1998 (A–F – E. smithi sp. nov.; G – E. cameroonensis sp. nov.; H – E. carinaticollis (Basilewsky, 1956)). I–R – Epimetopus Lacordaire, 1854 (I–N – E. mendeli Fikáček et al., 2011; O – E. cf. burruyacu Oliva, 1986; P – E. multiporus Perkins, 2012; Q – E. clandestinus Perkins, 2012; R – E. thermarum Schwarz & Barber, 1917). S–Z – Eumetopus Balfour-Browne, 1949 (S–Y – E. acutimontis Ji & Jäch, 1998; Z – E. bullatus (Sharp, 1875)).A, I, S – sternite VIII; B, J, T – tergite VIII; C, K, U – sternite IX; D, L, V – aedeagus dorsally; E, M, W – aedeagus laterally; F, N, X – aedeagus ventrally (basal part omitted in X); Y – sperm pump. Color coding: green – ventral projections of the median lobe; red – median lobe; blue – paramere (pale blue – dorsal lobe; dark blue – ventral lobe). Not to scale.

Fig. 7. Biology of Epimetopidae. A–D – Eumetopus acutimontis Ji & Jäch, 1998 in Vietnam, Khánh Hòa Prov., Ba Ho Waterfalls National Park, 12°23.131′N 109°08.052′E:A–B – alive specimens on wet sandy shores; C – specimen buried in wet sand; D – general view of the locality. E–F – locality of Epimetopus surinamensis Perkins, 2012 in Suriname: Sipaliwini, Wehepai, 2°21.776′N 56°41.861′W (SR10-0904-01A) (E – general view; F – detail of sandy banks from which specimens were collected). G–H – locality of Epimetopus simplex Perkins, 1979 in Venezuela, Guarico, Rio San Antonio, 9°46.32′N 67°21.177′W (VZ09-0108-02A) (G – detail of gravelly shore show which specimens were collected; H – general view). I–J – marshy roadside ditch with Epimetopus venezuelensis Perkins, 2012 in Venezuela, Apure, ca. 1 km N Rio Claro, 7°10.162′N 67°38.69′W (AS-06-009). (I – general view; J – detail of the microhabitat). Photos by A. Sazhnev (A–C), A. Prokin (D), A. Short (E–J).

Fig. 14. Habitus photographs of the known species of Eumetopus Balfour-Browne, 1949. A – E. acutimontis Ji & Jäch, 1998, paratype from China: Hainan (NHMW); B – E. asperatus (Champion, 1919), specimen from Nepal: Koshi Valley (NMPC); C – E. bullatus (Sharp, 1875), specimen from India: Maharashtra, Sawantwadi (NMPC); D – E. flavidulus (Sharp, 1890), specimen from India: Meghalaya, Bagmara (NHMW); E – E. maindroni (Régimbart, 1903), specimen from India: Maharashtra, Sawantwadi (NHMW); F – E. schuelkei Jäch, 2002, paratype from central Laos; G – E. tibialis Ji & Jäch, 1998 from Thailand, Ban Na env. (NMPC); H – E. weigeli Skale & Jäch, 2003, holotype from Nepal (NHMW). Scale bars: 1 mm.

Fig. 15. Elytral sculpture and male genitalia of Eumetopus Balfour-Browne, 1949. A–H – elytral sculpture, same specimens as in Fig. 14: A – E. acutimontis Ji & Jäch, 1998; B – E. asperatus (Champion, 1919); C – E. bullatus (Sharp, 1875); D – E. flavidulus (Sharp, 1890); E – E. maindroni (Régimbart, 1903); F – E. schuelkei Jäch, 2002; G – E. tibialis Ji & Jäch, 1998; H – E. weigeli Skale & Jäch, 2003. I–L – male genitalia of examined specimens, large basal portion of the phallobase omitted (dorsal and lateral view): I – E. acutimontis from Vietnam; J – E. flavidulus from India: Andhra Pradesh; K – E. maindroni from India: Gujarat; L – E. weigeli from India: Uttarakhand.