Zhilin Chen longhorned beetle (Drumontiana zhilini) related to D. amplipennis and similar to D. costata

NEWS - Researchers from Yangtze University in Hubei and Qingdao Hotincomon Agricultural Materials Marketing Co., Ltd in Shandong reported Zhilin Chen longhorned beetle (Drumontiana zhilini sp. nov.) from Huaping National Nature Reserve in Guangxi, China, as a new species closely related to D. amplipennis (Gressitt, 1939) and similar to D. costata Komiya & Niisato 2007.

Drumontiana Danilevsky 2001 (Coleoptera: Cerambycidae: Prioninae) was established based on the Southeastern Palaearctic and Oriental species Casiphia lacordairei Semenov, 1927 from Xizang, Yunnan and Northern Vietnam. Komiya & Niisato (2007) described four new species from China and Indochina, and transferred Psephactus amplipennis Gressitt 1939 to the genus.

Recently Ying-Qi Wang and colleagues, during an investigation of insect diversity in the Nanling Mountains, discovered an unknown species of Drumontiana. D. zhilini was described from Guangxi, China. Habitus and terminalia of males of the new species and the closely related species D. amplipennis.

Male: Body length 14.20 mm (measured from vertex to elytral apices), humeral width 5.10 mm. Body mostly pale reddish brown. Head pale reddish brown, except for inner margins of mandibles which are blackish brown.

Antennae dark reddish brown. Ventral surface pale reddish-brown. Body moderately clothed with fine light yellowish pubescence, which is particularly long and dense on head, pronotum, scutellum, elytra. Ventral surface sparsely covered with short pale yellowish pubescence.

Head narrower than base of pronotum, with an obvious longitudinal median sulcus; frons short, transverse, densely and coarsely rugulose-punctate; vertex slightly concave, coarsely rugulose-punctate. Eyes well developed, convex, finely faceted, with eye diameter longer than gene.

Antennae distinctly shorter than body, 0.70 times as long as body; scape short, thickened apically, rugulose-punctate, with a distinct and complete ridge on lower margin of the outer side, and apex and an incomplete ridge on apical half of upper margin of the outer side; antennomeres III–IX strongly flattened, each antennomeres provided with two complete distinct longitudinal ridges on dorsum; scape shorter than antennomere III, remaining antennomeres gradually decreasing in length distally, antennomere IX slightly arcuate, slightly shorter than III and slightly longer than IV.

Pronotum wider than long, widest at basal 1/4, 0.67 times as wide as basal width, with apical margin slightly narrower than basal margin; each side equipped with a pronounced small tooth at basal 1/4, which is acute apically, directed laterally; apical margin straight; basal margin roundly expanded backwards; convex disc, densely and finely punctured. Scutellum triangle, with slightly rounded apex, 0.61 times as long as prothorax, with small and dense punctures.

Elytra 1.96 times as long as humeral width, obviously broader than prothorax, gradually narrowed toward apices which are rounded apically; disc densely and finely granulate, provided with two fine longitudinal ridges on each elytron.

Ventral surface sparsely and finely punctured. Legs long and slim; metafemora slightly exceeding elytral apices; metatibiae greatly compressed and broadened; metatarsus 0.92 times as long as metatibia, with first metatarsomere obviously long, 1.56 times as long as following two tarsomeres combined.

Male terminalia. Tergite VIII semicircle, 0.84 times as long as width. Sparsely covered with long setae, spiculum gastrale shorter than ringed part of tegmen. Spiculum relictum shorter than half the length of spiculum gastrale.

Tegmen rather distinctly widened in posterior third, with apical margin roundly expanded backwards; parameres about 1/4 the length of tegmen, covered with a few long setae. Median lobe moderately curved in lateral view, obviously longer than tegmen; median struts 1.26 times as long as median lobe; ventral plate tapered at apex.

Female: Body length 27.83 mm (measured from vertex to elytral apices), humeral width 8.70 mm. Body black reddish brown. Abdominal ventrites black reddish brown, obviously darker in apical half of each abdominal ventrite. Legs blackish reddish brown, except for tarsi light reddish brown.

Left antenna missing antennomeres VI–XI; right antenna missing antennomeres V–XI; scape obviously shorter than antenna III, slightly longer than IV. Pronotum wider than long, each side furnished with a pronounced large tooth at basal 1/4, which is obtuse apically, obviously directed backwards.

Elytra 2.32 times as long as humeral width, obviously broader than prothorax, widest around middle; lateral margins gently widened from humeri to middle, then arcuately convergent to rounded apices; disc densely and finely granulate.

Ventral surface sparsely and finely punctured. Abdominal ventrites with distinctly punctures, first abdominal ventrite longest, apex of terminal sternite almost straight. Legs long and slim; metafemora almost reaching the posterior margin of abdominal segment IV; metatarsus 0.74 times as long as metatibia, with first metatarsomere obviously long, 1.37 times as long as following two tarsomeres combined.

The species is named after Mr. Zhilin Chen (Guangxi Normal University, Guangxi, China) in appreciation of his generosity in offering the specimen of this new species to be described. Chinese common name: 志林肚天牛. Distribution in China (Guangxi).

D. zhilini superficially resembles D. amplipennis because of similar integral coloration. However, it differs in head and scape with dense and coarse rugulose punctures; male scape with a distinct protuberance on the apical half of the upper outer margin; pronotal teeth lateral male on basal 1/4 small, apical acute, not directed backward; part of tegmen ring rounded at apical margin.

While D. amplipennis has head and antennal scape with sparse and fine rugulose prickles; male scape without protuberance on upper margin of lateral outer; Male pronotum with blunt teeth on basal 3/10 on each side, sometimes large and sharp, which are clearly directed backwards; the tegmen ring part is almost straight on the apical edge.

D. zhilini is also similar to D. costata. However, the antennae of the new species are 0.70 times longer than the body; male pronotum with small lateral teeth protruding on the basal 1/4 of each side, female pronotum with wider lateral edges; elytra 1.96 times longer than humerus width; tegmen ring rounded at apical edge.

While in D. costata males have antennae 0.80 times longer than body; male pronotum with two teeth on each side; male scutellum more rounded; elytra 2.2-2.3 times longer than humerus width; tegmen ring part almost straight on apical edge.

Original research

Ying-Qi Wang, Ping Wang, Guang-Lin Xie & Wen-Kai Wang (2024). Drumontiana zhilini sp. nov., a new species from Guangxi, China (Coleoptera: Cerambycidae: Prioninae). Zootaxa 5528 (1): 725–732, DOI:10.11646/zootaxa.5528.1.48

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