Lucanus brivioi, Zilioli, 2003

Zhan, Zhihong & Young, Daniel K., 2023, A taxonomic assessment and redefinition of the Lucanus fortunei species group in China (Coleoptera: Lucanidae: Lucaninae), Zoological Systematics 48 (4), pp. 279-360 : 308-309

3.3 Lucanus brivioi species group, sensu novo

Description. Male: 1) ratio of mandibular length to length of head and pronotum for L. brivioi species group 1.4 –1.6; 2) shape of major inner mandibular tooth usually triangular, or single-pointed, not flattened on both sides; 3)>6 small, inner mandibular teeth (denticles) located above and below major inner mandibular tooth; 4) clypeolabrum developed, strongly protruding at middle, triangular anteriorly; 5) posterolateral head usually flat or weakly rounded, usually less than 1.2× pronotal width; 6) prothoracic tibiae each bearing>5 spines from apex to midlength; mesothoracic tibiae each bearing two, or <4 spines along midlength; 7) elytra usually concolorous with head and pronotum, surface smooth and with metallic luster along elytral suture; 8) basal aedeagus slender. Female: 1) apical mandibular teeth strongly incurved, strongly sharped or forming acute angle; 2) right inner mandibular tooth with a broad, flat inner ridge, with anterior tip only slightly behind apex of mandible, forming a gap behind mandibular apex, asymmetrical to left inner mandibular tooth; 3) apical pronotum wide and protruding, usually forming an obtuse angle at front; posterolateral pronotal corner enlarged, subequal in width to anterior pronotal ridge; 4) prothoracic tibiae strongly enlarged, 2nd distal spines significantly larger than 3rd and 4th; 5) preocular region strongly developed, forming acute angle apically; postocular margins weakly developed, narrower than width of proceoluar margins.

Body length 51.0– 75.4 mm (Major ♂), 50.9– 45.5 mm (Median ♂), <44.9 mm (Minor ♂); 28.5–38.4 mm (♀).

Distribution. Mainly distributed in Central East, Southeast and Southwest of China, including Anhui, Zhejiang, Fujian, Taiwan, Jiangxi, Hunan, Hubei, Sichuan, Chongqing, Guangdong, Guangxi, Guizhou, and Yunnan Provinces.

Natural history. Adults. Adults of the L. brivioi group are active from early May to the end July. Males tend to flight during the daytime, finding suitable host plants, feeding, and mating with females. Altitudinal range of the L. brivioi species is above 1200 m. Most adults showed little reactivity to light and were weakly attracted to the light trap, but still some species were sensitive to the light-trap. Adult longevity of L. brivioi species group is typically 2–5 weeks. Larvae. Little known of larvae in the L. brivioi species group. Females usually created “tunnels” within humus, but they will not drag leaves into these tunnels to form dumpling-like spheres. known larvae of L. brivioi species group are believed to have three instars within 12 months. however, there are no recorded successful rearings of any L. brivioi species.

Key for Lucanus brivioi species group (♂).

1. Major mandibular tooth strongly developed, located along midlength of mandible near anterior forks .............................................. 3

Major mandibular tooth weakly developed or absent; inner small mandibular teeth located on mandibles.........................................2 2. Body reddish to brownish, <5 inner small mandibular teeth located on mandibles ................................................................. L. miwai

Body reddish,>5 inner small mandibular teeth located on mandibles ............................................................................. L. yulaoensis 3. Mandibular forks well developed, the upper fork branch always subequal in length to the lower fork branch....................................4

Mandibular forks weakly developed, the upper fork branch always longer than the lower fork branch .............................................. 9 4. Mandibles incurved at basal 1/3 and straight along midlength, width of head nearly subparallel to that of pronotum .............. L. fonti

Mandibles incurved along midlength; width of head significantly grerater than that of pronotum ......................................................5 5. More than eight inner mandibular teeth; major mandibular tooth triangular but not pointing forward............................. L. hewenjiae

Fewer than eight inner mandibular teeth; major mandibular tooth triangular and pointing anteriorly ................................................. 6 6. Mandibles incurved basad major mandibular tooth.............................................................................................................................. 7

Mandibles not incurved basad major mandibular tooth .......................................................................................................................8 7. Prothoracic tibiae brownish to black ......................................................................................................................... L. szetschuanicus

Thoracic tibiae yellowish or each bearing yellowish stripes .............................................................................................................. 13 8. Apical fork relatively more incurved, distance between upper and lower forks greater, surface of head and pronotum covered with vestiture of short setae........................................................................................................................................ L. cenwanglaoshanus

Apical fork relatively less incurved, distance between upper and lower forks shorter, surface of head and pronotum smooth .............

......................................................................................................................................................................................... L. zhuxiangi

9. Body covered with vestiture of long, yellowish setae ........................................................................................................ L. formosus Body smooth, or covered with vestiture of short, indistinct setae ......................................................................................................10

10. Inner small mandibular teeth absent along mandibular bases ............................................................................................................ 12 Inner small mandibular teeth located along basal mandibles ............................................................................................................. 11

11. Each mandible significantly incurved near base, each with a single, small inner basal mandibular tooth ............................... L. fujitai Mandibles not incurved, with>3 inner small, basal mandibular teeth ............................................................................ L. deuveinaus

12. Prothoracic tibiae each bearing>8 spines, major mandibular tooth well developed.................................................... L. zhanbishengi Prothoracic tibiae each bearing 6–7 spines, major mandibular tooth pointing anteriorly........................................................ L. brivioi

13. Mandibles not narrowed basad major mandibular tooth; each mandible strongly incurved near base.............................. L. fairmairei Mandibles narrowed basad major mandibular tooth; mandibular bases slender ..................................................................... L. liuweii

Key for Lucanus brivioi species group (♀).

1. Pronotum relatively narrow, posterolateral margins subequal or nearly subequal in width to that of anterior margins .......................2 Pronotum flat, stout or rounded, posterolateral margins narrower than anterior margins.....................................................................5

2. Body yellowish or brownish, body covered with vestiture of yellowish setae .....................................................................................3 Body black, surface smooth with metallic sheen along the elytral suture ............................................................................................4

3. Thoracic tibiae yellowish or brownish; first two prothoracic tibial spines significantly enlarged...................................... L. formosus Thoracic tibiae brownish or black; first two prothoracic tibial spines weakly enlarged............................................................. L. fonti

4. Anterior pronotal margin angulate mesally, middle of the pronotum convex.................................................................... L. hewenjiae Anterior pronotal margin relatively rounded anteriorly, middle of the pronotum weakly or not convex ................................ L. brivioi

5. Thoracic femora black, or concolorous with thoracic tibiae................................................................................................................. 6 Thoracic femora with yellowish stripes ...............................................................................................................................................7

6. Pronotum well rounded anteriorly, middle of the pronotum not convex ..............................................................................................8 Pronotum weakly rounded, anterior margin angulate mesally, pronotum convex along midlength ................................................... 11

7. Venter conspicuously setose, pronotum convex along the midlength ...................................................................................... L. miwai Venter only moderately setose, pronotum not convex along midlength ............................................................................................. 10

8. Elytra less metallic along suture, mandibles relatively stout, incurved along basal 1/3 .................................................. L. deuveinaus Elytra strongly metallic along suture, mandibles relatively slender, incurved along basal 1/3 and distally .........................................9

9. Posterior pronotum strongly enlarged; distal two ptothoracic tibial spines relatively blunt, distal spine slightly excurved................... .................................................................................................................................................................................... L. zhanbishengi Posterior pronotum weakly enlarged, distal two prothoracic tibial spines sharply pointed apically .................. L. cenwanglaoshanus

10. Mesothoracic and metathoracic femora with yellowish stripes; preocular margin well developed, angulate.......................... L. liuweii Prothoracic , mesothoracic and metathoracic femora with yellowish stripes; preocular margin poorly developed, rounded.................. ......................................................................................................................................................................................... L. zhuxiangi

11. Angularity of posterolateral pronotum sharp, pronotum not enlarged along midlength; preocular margin developed, angulate ........... ................................................................................................................................................................................. L. szetschuanicus Angularity of posterolateral pronotum obscure, pronotum relatively enlarged along midlength; preocular area poorly developed, margin more rounded ........................................................................................................................................................ L. fairmairei