Aegosoma ripaillei Koshkin & Drumont, 2023

Koshkin, Evgeny S. & Drumont, Alain, 2023, A new species of the genus Aegosoma Audinet-Serville, 1832 (Coleoptera Cerambycidae, Prioninae) from South China and Northeast Myanmar, Zootaxa 5239 (4), pp. 593-600 : 593-599

Aegosoma ripaillei Koshkin & Drumont sp. n.

( Figs 1 , 2A , 3A, 3F , 4A, 4B ) http://zoobank.org/ urn:lsid:zoobank.org:act:41C3DE76-3C58-45C7-A5C3-3B69F75FA5F9

Type material. Holotype ( Figs 1 A, B, C ): ♁, China, Yunnan [province], Weixi [county], Lancang , VI.2013, leg. local collector (ex ADC, will be deposited in RBINS; I.G.: 34.537).

Paratypes: (25 specimens — 11 males and 14 females): 1 ♁, same data as holotype (ex ADC, will be deposited in IZCAS) ; 1 ♀, same data as holotype (ex ADC, will be deposited in RBINS; I.G.: 34.537) ; 1 ♁, 2 ♀, China, Yunnan province, Weixi county, Weideng, VI.2021, leg. local collector ( EKC) ; 1 ♁, China, Yunnan [province], Weixi [county], Baijixun , VII.2020, leg. local collector ( ADC) ; 2 ♁, same data but VI.2021 ( ADC, EKC) ; 1 ♁, China, Yunnan [province], Weixi [county], Lianglu, VII.2021, leg. local collector ( CRC) ; 1 ♁, 1 ♀, China, Yunnan [province], Yingjiang [county], Tongbiguan , VIII.2014, leg. local collector ( ADC) ; 1 ♀, China, Yunnan [province], Yingjiang [county], Tongbiguan , 2500 m, VII.2003, leg. local collector ( ADC) ; 1 ♁, China, Yunnan province, Chuxiong area , Shuangbai county (N part of Mt. Ailaoshan ), 2000 m, VI–VIII.2018, leg. local collector ( EKC) ; 1 ♀, China, Yunnan [province], Xinping [county], Mt Ailaoshan , 2300 m, 10.VI.2014, leg. local collector ( ADC) ; 1 ♀, China, Yunnan [province], Yunlong [county], Caojian , VI.2021, leg. local collector ( ADC) ; 1 ♀, China, Yunnan [province], Mengla [county], Menglun, Mt Daheishan , 1000 m, 1–20.V.2010, leg. local collector ( ADC) ; 1 ♁, China, Yunnan [province], Mengla [county], Menglun , VII.2020, leg. local collector ( ADC) ; 1 ♀, China, Yunnan [province], Diqing [Tibetan Autonomous Prefecture], VI.2010, leg. local collector ( ADC) ; 1 ♁, China, W Yunnan [province], Fugong [county], Nujiang valley , Mt Biluoxueshan , 2000 m, 8.VI.2020, leg. local collector ( ADC) ; 1 ♀, China, W Yunnan [province], Fugong [county], Nujiang valley , 2000 m, 7.VI.2020, leg. local collector ( ADC) ; 1 ♀, China, W Yunnan [province], Tengchong, Baoshan area , 1500 m, 8.V.2020, leg. local collector ( ADC) ; 1 ♀, China, W Yunnan [province], Tengchong, Mt Gaoligongshan , VI.1999, leg. local collector (ex ADC, will be deposited in IZCAS) ; 1 ♀, China, W Yunnan [province], Yongde [county], 15.IX.2000, leg. Yin ( NDC) ; 1 ♁, China, S Yunnan [province], Lanchang [county], Mt Hei , 15.IX.1999, leg. Yin & Li ( NDC) ; 1 ♀, NW Myanmar, [Kachin state], Myit [k]yina, Knakaya vill., 2500 m, VI.2005, leg. Yi et al. ( ADC).

Description

Habitus elongated, depressed, oblong, dark-brown satin in males, almost black females.

Head longer than wide, sub-cylindrical, sparsely granulated ( Fig 3A ). Mandibles large, strongly punctuated in the external side, except for apex. A weakly punctate depression at the base of the mandibles continues into the smooth and sloping inner side of the mandible. Inner side of left mandible with a large tooth; right mandible with a small one. Labrum with yellow setae. Antennal tubercles small; their top part is shaped as a semicircular visor. The eyes are relatively small, kidney-shaped; the upper lobe is smaller than the lower one. Median groove between eyes narrow and shallow. The areas around the eyes covered with sparse short yellow setae.

Antennae dark brown, much shorter than body, length reaching the three quarter of the elytral length in males and reaching the middle of the elytra in females. Ratio between antenna length (measured from the base of scape to the apex of segment XI) and body length (from the tip of the mandible to the apex of elytra) in males is 0.7–0.8, in females ca. 0.6. Scape is thick and subcylindrical, densely granulated. Segments III and IV thick, coarsely granulated, and denticulate at the inner side. Segment III longest, roughly equal to the length of combined segments IV to VI (or slightly shorter). Segment IV is approximately two times shorter than segment III. Segments from V to XI thinner and shorter, smooth (except for anterior part of segment V, which is finely granulated). Segment V is about 1.5–2 times as long as each of segments VI–X, which are approximately equal in length. Last segment is flattened at the apex, approximately 1.5 times as long as segment X.

Pronotum dark brown, wide, trapezoidal shaped; ratio between maximum width and length is 1.65–1.9 in males, and 1.9–2 in females. Anterior margin straight, the angles on it slightly protruding. Posterior margin of pronotum convex at middle and forms two slightly protruding rounded angles. Disc strongly punctate, with two tubercles in apical half closer to lateral margins. Two other prominences are located in the central zone of the pronotum. Four longitudinal bright spots formed by long golden hairs at angles of pronotum. In some specimens, these spots are poorly visible. The rest of the pronotum pubescent with sparse short yellow setae.

Scutellum dark brown, semicircular, covered with sparse short yellow hairs at base.

Elytra dark brown with strong shine, glabrous, finely punctate, flattened, subparallel, long, 2.4–2.6 times longer than its maximum width in humeri area, rounded at apexes. On each elytron with four weakly expressed subparallel costae. Two inner costae are most pronounced, start from humeri, subparallel to each other in basal part and connected in 1/4 from apex elytra. Two outer costae shorter and more inconspicuous.

Legs dark brown, flattened, slender. Inner side of profemur and protibia finely granulated, other parts of legs finely punctated. Inner side of meso- and metatibia covered with short yellowish hairs. Claws segment longer than the combined three others segments.

Gula, prosternum, mesosternum and metasternum finely punctuated and densely covered with long yellow hairs. Prosternal process is long, gradually expanding towards the apex. Abdominal sternites glabrous and slightly covered with sparse short yellow setae. Last sternite strongly emarginated, with yellow hairs at the apex.

Body length (measured from the tip of the mandible to the elytral apex): Males: 27–45 mm (holotype: 36 mm), females: 35.5–47.5 mm. Body width: males: 7.5–12 mm (holotype: 9.5 mm), females: 10–13.5 mm.

Diagnosis. Aegosoma ripaillei sp. n. is characterized by short antennae, short antennal segment III, weak denticulation in the inner side of antennal segments, shiny elytrae with almost indistinct costae, and yellow longitudinal spots on the pronotum.

The new species is most similar to A. pseudornaticolle Ripaille & Drumont, 2017 ( Figs 2B & C , 3B, 3G , 4C ) differing from it in the following features:

– longer and slender body in males (males of A. pseudornaticolle has a more massive habitus);

– shiny elytra with weakly expressed costae (in A. pseudornaticolle , elytra relatively mat with the costae are clearly visible);

– thinner and shorter antennal segment III, the length of which is approximately equal to the sum of the lengths of segments IV, V and VI (in A. pseudornaticolle , the length of segment III is the total length of segments from IV to VII, or even to VIII) ( Figs 3 F & G );

– in males, the inner side of antennal segment IV is less denticulated ( Figs 3 F & G );

– posterior angles of pronotum less protruding ( Figs 3 A & B );

– yellow spots on the pronotum are diffuse and longitudinally elongated; almost the entire rest of the pronotum is covered with sparse short yellow hairs (in A. pseudornaticolle , the yellow spots are distinctly defined and transversely elongated, and the rest of the pronotum has almost no yellow hairs);

– semicircular scutellum (in A. pseudornaticolle , the scutellum is more or less triangular shape);

– prosternal process is slightly expanded to the apex (in A. pseudornaticolle the apical part of the prosternal process is strongly expanded and has a drop-liked shape) ( Figs 4 A, B & C );

– pubescence from yellow hairs of the gula, prosternum, mesosternum and metasternum is more pronounced ( Figs 1 B, C, E & F ).

Aegosoma ripaillei sp. n. is also similar to several other Aegosoma species inhabiting mainland China: A. sinicum White, 1853 , A. ornaticolle White, 1853 and A. fuliginosum Drumont, Ripaille & Collard, 2019 .

The new species differs from Aegosoma ornaticolle ( Figs 2D & E , 3 D & I , 4 D ) in the following main features:

– smaller on average; length of A. ripaillei 27–47.5 mm, and A. ornaticolle 37–52 mm;

– shiny elytra without any hairs (in A. ornaticolle , elytra matte with pubescence from short hairs);

– short antennae, reaching the three quarter of the elytral length in males and reaching the middle of the elytra in females (in A. ornaticolle , the antennae are long, in males extending beyond the apices of the elytra, and in females reaching the last quarter of the length of the elytra);

– in males, antennal segments IV and V less granulated, and the inner side is much less denticulated ( Figs 3 F & I );

– apices of antennal segments from VI to X are rounded on the external side (in A. ornaticolle with acute angle) ( Figs 3 D & I );

– more trapezoidal shape of the pronotum in males;

– yellow spots at the lower margin of pronotum are diffuse and longitudinal (in A. ornaticolle , these spots are distinctly defined and transversely elongated) ( Figs 3 A & D );

– apex of elytra without acute tooth ( A. ornaticolle has small acute tooth on the elytron apex).

The new species is similar to Aegosoma fuliginosum ( Figs 2 H & I , 3 E & J , 4 F ) in body constitution, dark ground color, shiny elytrae, and weakly expressed elytral costae. At the same time, A. ripaillei sp. n. has such strong differences from A. fuliginosum as:

– short antennae (in A. fuliginosum long antennae; in males, the antennal length is approximately equal to the length of the beetle from the tip of the mandible to the elytral apex);

– length of segment III is approximately equal to the sum of the lengths of segments IV, V and VI (in A. fuliginosum , the length of segment III slightly shorter than total length of segments IV and V ( Figs 3 F & J );

– in males, the inner side of antennal segments IV and V is slightly denticulated (strongly denticulated in A. fuliginosum ) ( Figs 3 F & J );

– the presence of yellow spots on the pronotum (in A. fuliginosum , the pronotum is almost uniformly colored, with diffuse slight pubescence from short yellow hairs) ( Figs 3 A & E );

– apex of elytra rounded, without acute tooth ( A. fuliginosum has small acute tooth on the elytron apex).

Finally, Aegosoma ripaillei sp. n. is similar to A. sinicum ( Figs 2 F & G , 3 C & H , 4 E ), differing from it in the following features:

– smaller on average;

– longer and slender body ( A. sinicum has more massive habitus);

– short antennae in males (in males of A. sinicum , the antennae are longer and usually slightly do not reach the elytral apices);

– in males, antennal segments IV and V less granulated, and the inner side is less denticulated ( Figs 3 F & H );

– shining elytra with weakly expressed costae (in A. sinicum , elytra matte with well-defined costae);

– granulosity on pronotum rough and large (in A. sinicum it is finer) ( Figs 3 A & C );

– yellow spots on pronotum brighter and longitudinally elongated (in A. sinicum , yellow spots are paler, more diffuse and transversely elongated) ( Figs 3 A & C );

– well-defined yellow pubescence of the metasternum (in A. sinicum , the pubescence is weakly expressed).

Distribution. South China (currently only known from Yunnan province) and Northeast Myanmar (Kachin state).

Etymology. The new species is dedicated to our colleague Claude Ripaille (Lias, France) in recognition of his important contribution to the knowledge of East and Southeast Asia Aegosomatini including the description of three new species of Aegosoma found in China.

Notes. The new species inhabits mountain forests at altitudes of 1000–2500 m. In Yunnan, A. ripaillei sp. n. occurs sympatrically with A. ornaticolle in some locations; for example, specimens of both species are known from Tongbiguan in Yingjiang county ( Fig. 2D ). Also, the new species co-occur with A. fuliginosum ; both species are collected in Mt. Ailaoshan (2300 m), Xinping, Yunnan ( Drumont & Komiya 2020). The ranges of A. ripaillei and its closest species inside the genus, A. pseudornaticolle , do not overlap. The latter species is distributed only in Sichuan province ( Ripaille & Drumont 2017).

Figures

FIGURE 1. Aegosoma ripaillei sp. n., habitus. A, B, C—holotype ♁, 36 mm, China, Yunnan, Weixi, Lancang, VI.2013 (in RBINS); D, E, F—paratype, ♀, 43 mm, China, Yunnan province, Weixi county, Weideng, VI.2021 (in EKC); A, D—dorsal view, B, E—ventral view, C, F—lateral view. (Figures A, B & C by Julien Lalanne, figures D, E, F by Evgeny Koshkin).

FIGURE 2. Aegosoma spp., habitus, dorsal view. A—A. ripaillei sp. n., paratype ♁, 42 mm, China, Yunnan province, Weixi county, Weideng, VI.2021 (in EKC); B—A. pseudornaticolle Ripaille & Drumont, 2017, holotype ♁, 45 mm, China, Sichuan province, Mts Nan Jiang, Micang Shan, VI.1999 (in RBINS); C—A. pseudornaticolle, allotype ♀, 42 mm, China, Sichuan province, Longmen Shan, Yanmenba, VII.2002 (inADC); D—A. ornaticolle White, 1853, ♁, 42 mm, China, Yunnan, Yingjiang, Tongbiguan, VII.2014 (in ADC); E—A. ornaticolle, ♀, 40 mm, China, Tibet, Motuo, Hanmi, 2000 m, VIII.2017 (in EKC); F—A. sinicum White, 1853, ♁, 53 mm, China, Shanghai, Pudong, VII.2016 (in EKC); G—A. sinicum, ♀, 46 mm, same data as male (in EKC); H—A. fuliginosum Drumont, Ripaille & Collard, 2019, ♁, 45 mm, Vietnam, Yen Bai province, Mu Cang Chai, 1400–1500 m, VI.2021 (in EKC); I—A. fuliginosum, ♀, 46 mm, same data as male (in EKC). (FiguresA, E, F, G, H, I by Evgeny Koshkin, figure B by Camille Locatelli, figure C by Claude Ripaille, figure D by Julien Lalanne).

FIGURE 3. Aegosoma spp., male head, pronotum and antennae, dorsal view. A, F—A. ripaillei sp. n., paratype; B, G—A. pseudornaticolle, holotype; C, H—A. sinicum; D, I—A. ornaticolle; E, J—A. fuliginosum. Collecting data and picture authors as Fig. 2.

FIGURE 4. Aegosoma spp., prosternal process. A—A. ripaillei sp. n., paratype ♁; B—A. ripaillei sp. n., paratype ♀; C—A. pseudornaticolle, holotype ♁; D—A. ornaticolle, ♀; E—A. sinicum, ♁; F—A. fuliginosum, ♁. Collecting data and picture authors as Fig. 2.