Megistophylla octobracchia Gao & Li, 2019

Gao, Chuan-Bu, Li, Chun-Lin & Fang, Hong, 2019, Megistophylla octobracchia Gao & Li, new species (Coleoptera: Scarabaeidae: Melolonthinae) from Yunnan, China, and redescription of M. grandicornis (Fairmaire, 1891), Zootaxa 4565 (4), pp. 515-522 : 516-518

Megistophylla octobracchia Gao & Li , new species

( Figs. 1, 2 , 5–11 , 19–25 , 33–37 )

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Type locality. CHINA: Yunnan Province: Yingjiang County: Xima Town .

Type material. Holotype, male, labeled: “ Yunnan Province, Dehong Zhou / Yingjiang County, Xima Town / 5.?. 2018 lamp / Collector Yang , Wei-zong [typeset, Chinese and English ] // HOLOTYPE ♂ / Megistophylla octobracchia sp. nov. / Chuan-bu Gao & Chun-lin Li / det. 2018 [typeset, red label]”, deposited in SYAU; paratype, male: “ Yunnan Province, Dehong Zhou / Yingjiang County , Xima Town / 5.?. 2018 lamp / Collector Yang, Wei-Zong [typeset, Chinese and English] // PARATYPE ♂ / Megistophylla octobracchia sp. nov. / Chuanbu Gao & Chun-lin Li / det. 2018 [typeset, yellow label]”, deposited in SYAU; paratypes, 3 males: “Hulukou, Xima Town , Yingjiang / County, Yunnan, 1200 mm / 2018.?-? W.- Z. Yang leg. [typeset, Chinese or English] // PARATYPE ♂ / Megistophylla octobracchia sp. nov. / Chuan-bu Gao & Chun-lin Li / det. 2018 [typeset, yellow label]”, deposited in SYAU.

Description of holotype (male) ( Figs. 1, 2 , 5–11 , 19–25 , 33–37 ). Body length 14.5 mm; width across humeri 6.9 mm; body oval-elongate, dorsal surface densely punctate, punctures deep rugopunctate; head, pronotum, elytra and pygidium sparsely covered with long setae; scutellum with tiny setae ( Figs. 1, 2 ).

Colour: Antennae, head, pronotum and elytra brown; scutellum and legs reddish brown.

Head: Antennae with 10 antennomeres, antennal club composed of 5 antennomeres, strongly curved outwards, club 2.5 times longer than antennomeres 1–5 combined ( Fig. 5 ). Clypeus setiferous and punctate, anterior margin bow-shaped, reflexed and emarginate. Frons setiferous and densely punctate, frontoclypeal suture defined. Frontal carina distinctly raised, bent forwards medially. Clypeus 1.16 times width, and 0.91 times length of frons ( Fig. 6 ). Frons between eyes 2.1 times width of eye. Ocular canthus setaceous, length of canthus 0.6 mm.

Mouthparts: Labrum strongly depressed at middle ( Fig. 7 ). Mandible with wrinkled molar lobe and rounded notch in incisor lobe ( Figs. 8, 9 ). Mala of maxilla bears 3 strong, distal teeth ( Fig. 10 ). Mentum distinctly bilobate at apical half; paraglossae with several setae near inner margin ( Fig. 11 ).

Thorax: Pronotal surface densely rugopunctate and setaceous, setae long and sparsely distributed. Widest of pronotum at middle; anterior and posterior margins smooth; lateral margin moderately crenulate and setaceous; anterior and posterior angles obtuse ( Fig. 19 ). Scutellum triangular, 1.58 times wider than long; dorsal surface punctate and setiferous, punctures and setae tiny, setae longer than diameter of puncture ( Fig. 20 ). Ventral surface of thorax with long soft hairs. Prosternal process wedge-shaped ( Fig. 21 ). Dorsal surface of elytra setaceous and rugopunctate; sutural costa developed; epipleuron with long soft setae before apex ( Fig. 2 ).

Legs: Protibia tridentate, apical spur of protibia reaching middle of protarsomere 1 ( Fig. 1 ). Metafemora covered with long soft setae near anterior and posterior margins ( Fig. 2 ). Outer side of metatibia with a completed carina at apical 2/5; dorsolateral margin of metatibia with a thorn at basal 1/4; dorsomedial margin with one large thorn at front 1/3 and 3¯4 small thorns at basal half ( Fig. 22 ). Metatibia with two apical spurs of different sizes, spurs lanceolate-shaped; metatarsi 1.5 times longer than metatibia; basal metatarsomere 1.2 times longer than metatarsomere 2 ( Fig. 23 ). Each claw with a tooth medially ( Fig. 24 ).

Abdomen: Lateral sides with long setae; ventrite 2 with dense short setae; sternites 5, 6 with soft setae. Pygidium inverted trapezoid, 1.5 times wider than long; surface densely punctate and pubescent ( Fig. 25 ).

Genitalia: Phallobase 1.18 times longer than parameres; apical 1/4 narrow and basal 3/4 expanded laterally ( Fig. 33 ). Parameres symmetrical, with 8 long branches; lateral branches shorter; dorsal and ventral branches thin; middle branches thick; bases of parameres of lateral and dorsal branches enclosed with a membranous area ( Figs. 34, 35 ). Endophallus with slender temones on dorsum and a few small cone-shaped thorns near discal part ( Fig. 36 ). Spiculum gastrale Y-shaped ( Fig. 37 ).

Female. Unknown.

Variability. Paratypes differ in size (body length 14.8–15.7 mm, width across humeri 6.6–6.9 mm). Antennal club 2.1–2.3 times longer than basal antennomeres.

Diagnosis. Megistophylla octobracchia Gao & Li , new species can be distinguished from other Megistophylla species by the following combination of characters: antennal club composed of 5 long antennomeres; club curved outwards strongly, 2 times longer than basal antennomeres; dorsum of head, pronotum, elytra and pygidium with long soft setae; lateral margin of pronotum moderately crenulate and setaceous; epipleuron with long soft setae before apex; dorsomedial margin of metatibia with 4¯5 small thorns; parameres with eight branches.

Distribution. China (Yunnan).

Etymology. The specific name octobracchia means “eight-branched” referring to the branched parameres in the male genitalia of species that are unique in the genus Megistophylla .

Chinese name. 八岐多鳃金龟

Remarks. Up to now, Megistophylla octobracchia Gao & Li , new species is the third species of the genus known from mainland China. Xima Town (the type locality of the new species) is located at 24°51'24"N– 25°16'24"N and 97°44'54E–97°63'56E, between 820–2580 m a.s.l. ( Zheng & Li 1997). When using the key proposed by Li et al. (2016), M. octobracchia Gao & Li , new species will be carried to the couplet 5 without regard to the body length. We modify the key in the following manner to comprise M. octobracchia Gao & Li , new species:

5 Dorsal surface of elytra glabrous......................................................................... 6 - Dorsal surface of elytra setaceous.......................................... M. octobracchia Gao & Li , new species 6 Antennal club curved vertically in apical half.................................... M. grandicornis ( Fairmaire, 1891) - Antennal club gradually curved outwardly............................................ M. pentaphylla Arrow, 1925

Figures

FIGURES 1–4. Habitus of Megistophylla in dorsal (1, 3) and lateral (2, 4) view. 1, 2, Megistophylla octobracchia Gao & Li, new species, holotype; 3, 4, Megistophylla grandicornis (Fairmaire, 1891). Scale bar: 5.0 mm for 1–4.

FIGURES 5–18. Head of Megistophylla (5, 12 antennae; 6, 13 head; 7, 14 labrum; 8, 15 mandible, inner side; 9, 16 mandible, top side; 10, 17 maxilla; 11, 18 mentum). 5–11, Megistophylla octobracchia Gao & Li, new species, holotype; 12–18, Megistophylla grandicornis (Fairmaire, 1891). Scale bar: 1.0 mm for 5, 6, 12, 13; 0.5 mm for 7–11, 14–18.

FIGURES 19–32. Thorax and pygidium of Megistophylla (19, 26 pronotum; 20, 27 scutellum; 21, 28 prosternal process; 22, 29 metatibia; 23, 30 metatarsi; 24, 31 metaclaws; 25, 32 pygidium). 19–25, Megistophylla octobracchia Gao & Li, new species, holotype; 26–32, Megistophylla grandicornis (Fairmaire, 1891). Scale bar: 1.0 mm for 19–23, 25, 26–30, 32; 0.5 mm for 24, 31.

FIGURES 33–42. Male genitalia of Megistophylla (33, 38 male genitalia, lateral view; 34, 40 parameres, dorsal view; 35, 41 parameres, ventral view; 36, 42 endophallus; 37 Spiculum gastrale; 39 male genitalia, dorsal view). 33–37, Megistophylla octobracchia Gao & Li, new species, holotype; 38–42, Megistophylla grandicornis (Fairmaire, 1891). Abbreviations: Db, dorsal branch; Hl, hemispherical lobe; Mb, middle branch; Lb, lateral branch; S, sensilla; T, temones; Ub, ventral branch. Scale bar: 1.0 mm for 33–42.