Falsotrachystola xui, Wang & He & Wang & Wang, 2023

Wang, Yingqi, He, Tianlong, Wang, Ping & Wang, Wenkai, 2023, Description of a new species of the genus Falsotrachystola Breuning, 1950 (Coleoptera: Cerambycidae, Lamiinae), Zootaxa 5380 (3), pp. 295-300 : 296-298

Falsotrachystola xui sp. nov. (Ẁ氏LJDzƙ牛)

( Figs 1A–D , 2A–D , 3A–F , 4A–C )

Description ( Figs 1A–B , 2A–B , 4B–C ). Male. Length 15.0– 17.7 mm (measured from vertex to elytral apices), humeral width 6.0– 6.3 mm (measured across humeri). Body dark brown. Head, pronotum and elytra covered with short brown and light yellowish-brown setae. Antennae covered with short brown and light yellowish-brown setae, antennomeres VII–XI with dense yellowish-brown setae. Elytra without distinctly black setal spots, sometimes with a pair of vague pale black setal spots. Ventral surface covered with short brown and light yellowish-brown setae. Legs clothed with sparse grey-white and yellowish-brown setae, extremely dense and longer golden setae on apical half of tibiae.

Head with frons short, transverse, slightly convex, with dense and coarse punctures; vertex slightly concave. Eyes coarsely faceted and deeply emarginate; genae slightly longer than lower eye lobe. Antennae longer than body, about 1.8 times as long as body; antennomere VII surpassing elytral apex, antennal tubercles elevated, widely separated from each other; scape cylindrical, sparsely punctate, with an inconspicuous apical cicatrix; scape slightly longer than antennomere III, antennomere III longer than IV, about 1.2 times as long as IV, antennomeres IV–X gradually shortening, antennomere XI sharply pointed apically, nearly equal in length of V.

Pronotum distinctly wider than long, length about 0.7 times as long as the maximum prothorax width, anterior margin slightly wider than posterior margin; disc coarsely rugose-punctate, with three irregular and wrinkled calluses, two of them located before the middle and one slightly larger near basal middle, lateral spine conical with subacute apex, slightly directed backward.

Scutellum tongue-shaped, with slightly rounded apex.

Elytra about 1.7 times as long as humeral width, steeply declivous at apical 1/3; humeri distinctly produced laterally, almost parallel from basal to apical 2/5, then slightly arcuate to apex; disk with different sized tubercles, each elytron with tubercles or granules forming three carinae: the first short carina from the basal middle to basal 1/3; the second carina extending from near outside of basal 1/5 to apical 2/5; the third dorsolateral carina from humeri to apical 1/5; several small granules located among ridges and suture. Prosternum, mesanepisternum, and mesoventrite coarsely and shallowly punctate anteriorly. Mesosternal process without tubercle; mesocoxal cavities opened externally to mesepimera. Abdominal ventrites with distinctly punctures, first abdominal ventrite longest, apex of terminal sternite nearly straight.

Legs moderately long and slender, metafemora nearly straight, reaching fifth abdominal segment. First metatarsal segment shorter than following two segments combined; claws divergent.

Male genitalia ( Figs 3A–F ). Tergite VIII transverse, nearly truncated apically, length about 0.9 times as long as wide, clothed with sparse and short setae at sides, and slightly long and dense at middle; spiculum gastrale slightly longer than ringed part of tegmen; spiculum relictum shorter than a half of spiculum gastrale. Tegmen slightly bent in lateral view, paramere moderately long, length 1.3 times as long as width, apex with moderately dense setae; median lobe moderately curved in lateral view, distinctly shorter than tegmen; median struts about half length of median lobe, apex of ventral plate rounded; endophallus long, mostly membranous.

Female ( Figs 1C–D , 2C–D ). Length 18.5–20.5 mm (measured from vertex to elytral apices), width 6.5–8.0 mm (measured across humeri). Similar to male, but body distinctly broader, elytra with a pair of black setal spots near apical 2/5; antennae about 1.1 times as long as body, reaching elytral apex at antennomere IX, scape slightly longer than antennomere III, remaining gradually shorter in length, antennomere XI sharply pointed apically, nearly equal in length of V. Pronotum distinctly wider than long, length about 0.7 times as long as the maximum width, ventrite V slightly emarginate apically.

Remarks. At first glance, the new species is similar to Falsotrachystola asidiformis (Pic, 1915) , however, it can be easily distinguished from the latter by the combination of the following characters: antennae more elongate, about 1.8 times as long as body; elytra more elongate, about 1.7 times as long as humeral width, and elytra without distinctly black setal spots or with a pair of vague pale black setal spots in male. While in F. asidiformis , antennae slightly shorter, about 1.2 times as long as body; elytra slightly wider, about 1.6 times as long as humeral width, with a pair of obviously black setal spots ( Huang & Li, 2019).

Type material examined. Holotype (male): China: Guangxi Zhuang Autonomous Region, Hechi City, Jincheng District , Jiuxu Town , February 11, 2022, coll. by Tianlong He ; Paratypes: 2 males, same data as holotype ; 1 male, ditto except March 14, 2022, coll. by Zidan Xu; 1 male, ditto except April 3, 2022, coll. by Zidan Xu; 2 males, ditto except May 21, 2022, coll. by Zidan Xu; 1 male, ditto except June 2, 2022, coll. by Zidan Xu; 3 males and 2 females, ditto except June 21, 2022, coll. by Zidan Xu; 2 males and 2 females, ditto except August 3, 2022, coll. by Zidan Xu; 1 male, China, Guizhou Province, Qiannan Buyi and Miao Autonomous Prefecture , Duyun City , Pinglang Town , May 4, 2023, coll. by Zidan Xu; ditto except July 14, 2022, coll. by Zidan Xu.

The holotype (male) and one paratype (female) are deposited in the Insect Collection , College of Agriculture , Yangtze University, Jingzhou, Hubei, China (YZU) . 19 paratypes (15 males and 4 females) are deposited in the CTLH private collection of Tianlong He , Huainan, China .

Distribution. China (Guangxi, Guizhou).

Etymology. The species is named after Mr. Zidan Xu (Chengdu, China), in appreciation of his generosity in offering the specimens to be described.

Figures

FIGURES 1A–D. Falsotrachystola xui sp. nov. A–B. holotype, male; C–D. paratype, female; A, C. dorsal view; B, D. ventral view; Scale bar: 10 mm.

FIGURES 2A–D. Falsotrachystola xui sp. nov. A–B. holotype, male; C–D. paratype, female; A, C. lateral view; B, D. head, frontal view.

FIGURES 3A–F. Genitalia of Falsotrachystola xui sp. nov. A–B. tegmen; C–D. tergite VIII, spiculum relictum and spiculum gastrale; E–F. median lobe; A, C, E. ventral view; B, F. lateral view; D. dorsal view.

FIGURES 4A–C. Falsotrachystola xui sp. nov. A. view of the biotope of the collecting locality; B–C. habitus of live adults. (China: Guangxi).