Megistophylla grandicornis ( Fairmaire, 1891 )

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 : 518-520

Megistophylla grandicornis ( Fairmaire, 1891)

( Figs. 3, 4 , 12–18 , 26–32 , 38–42 )

Hecatomnus grandicornis Fairmaire, 1891: 202 ; Zhang & Li 1997: 772.

Megistophylla grandicornis: Arrow 1944: 634 .

Type locality. “Kiu-Kiang” [= China: Jiangxi Province: Jiujiang City ] . Type material examined. None.

Additional material examined. Male, labeled: “ Chongqing Fengjie / Peng Yang [Collector] / 2011. 5. 11 [typeset, Chinese] // Co-21-9759 / SWU [typeset] // Megistophylla grandicornis / ( Fairmaire, 1891) / det. GCHB 2018 [handwritten or typeset]”, deposited in SWU; male: “Yunana Kunming / Fengbo [Collector] / 2009. 0 5. 30 // Co-21-9063 / SWU // Megistophylla grandicornis / ( Fairmaire, 1891) / det. GCHB 2018 [handwritten or typeset]”, deposited in SWU; male: “Kunming Wenquan [Town] / 1980.?. 15 [handwritten] // Hecatomnus / grandicornis Fairm / Gu [19]90. 9. 14 [handwritten] // Megistophylla grandicornis / ( Fairmaire, 1891) / det. GCHB 2018 [handwritten or typeset]”, deposited in SYAU; male: “Gu 43 / Meitan [handwritten, Chinese] // 0 0 6 / Shennong [handwritten, Chinese] // Hecatomnus / grandicornis Fairm / Gu [19]90. 9. 14 [handwritten] // Megistophylla grandicornis / ( Fairmaire, 1891) / det. GCHB 2018 [handwritten or typeset]”, deposited in SYAU; male: “ Guizhou [handwritten, Chinese] // 0 16 [handwritten] // Hecatomnus / grandicornis Fairm / Gu [19]90. 9. 14 [handwritten] // Megistophylla grandicornis / ( Fairmaire, 1891) / det. GCHB 2018 [handwritten or typeset]”, deposited in SYAU; male: “ Fujian Liancheng Taipingliao / 1989. 6. 21 / Collector Jizu Zhang [handwritten, Chinese] // 56 [handwritten] // Hecatomnus / grandicornis Fairm / Gu [19]90. 9. 14 [handwritten] // Megistophylla grandicornis / ( Fairmaire, 1891) / det. GCHB 2018 [handwritten or typeset]”, deposited in SYAU; male: “3895 / Zhejiang Songyang [handwritten, Chinese] // Hecatomnus / grandicornis / Fairmaire 1991.?. 13 / Collector Zhiliang Zhang [handwritten, Chinese] // Megistophylla grandicornis / ( Fairmaire, 1891) / det. GCHB 2018 [handwritten or typeset]”, deposited in SYAU; male: “Kunming Wenquan [Town] / 1980.?. 21 [handwritten] // Hecatomnus / grandicornis Fairm / Gu [19]90. 9. 14 [handwritten] // grandicornis / ( Fairmaire, 1891) / det. GCHB 2018 [handwritten or typeset]”, deposited in SYAU.

Redescription (males) ( Figs. 3, 4 , 12–18 , 26–32 , 38–42 ). Body length 17.3–22.6 mm; width across humeri 8.1–10.1 mm; body oval-elongate, dorsal surface glabrous and punctate, shiny ( Figs. 3, 4 ).

Colour: Head, antennae, pronotum and scutellum reddish brown; elytra and legs brown to dark brown.

Head: Antennae with 10 antennomeres, antennal club composed of 5 antennomeres, curved vertically in apical half, club 2.4–2.6 times longer than antennomeres 1–5 combined; fifth basal antennomere sharply enlarged ( Fig. 12 ). Clypeus dense punctate, anterior margin bow-shaped, emarginate and reflexed. frons punctate, punctures denser than those on pronotum and elytra, slightly convex at middle. Frontoclypeal suture defined. Frontal carina distinctly raised transversally, bent forwards medially ( Fig. 13 ). Clypeus wider and shorter than frons. Frons between eyes 3.0–3.1 times wider than eye. Ocular canthus setaceous, length of canthus 0.7 mm.

Mouthparts: Labrum strongly depressed at middle ( Fig. 14 ). Mandible with developed wrinkled molar lobe and one big rounded notch one small notch in incisor lobe ( Figs. 15, 16 ). Mala of maxillae bears 4 distal teeth developed ( Fig. 17 ). Mentum bilobate at apical half; paraglossae with few setae near inner margin ( Fig. 18 ).

Thorax: Pronotal surface glabrous and dense punctate. Widest of pronotum at basal 2/5; anterior, posterior and lateral margins smooth; lateral margin reflexed moderately; anterior angles obtuse; posterior obtuse rounded ( Fig. 26 ); pronotum with 7–10 long setae close to lateral margin at anterior half. Scutellum triangular, punctate laterally, 1.5-1.6 times wider than long ( Fig. 27 ). Ventral surface of thorax with long, soft yellow setae. Prosternal process wedge-shaped ( Fig. 28 ). Dorsal surface of elytra glabrous and punctate, sutural costa developed, epipleuron with soft setae before apex ( Figs. 3, 4 ).

Legs: Protibia tridentate; apical spur of protibia sharp, tip reaching basal 1/3 of protarsomere 1. Metafemora covered with soft setae near anterior and rough setae near posterior margins. Outer side of metatibia with carina pubescent at apical 2/5. Dorsolateral margin of metatibia with a thorn at basal 1/4; dorsomedial margin with 3–6 thorns weakly developed ( Fig. 29 ). Apex of metatibia with two lanceolate spurs of different sizes. Metatarsi slightly longer than metatibia. Basal metatarsomere equal in length to metatarsomere 2 ( Fig. 30 ). Each claw with a tooth vertically medially ( Fig. 31 ).

Abdomen: Ventrite 2 with dense short setae; ventrites 5, 6 setiferous, setae long and sparsely distributed. Pygidium fan-shaped, 1.3-1.4 times wider than long, convex at middle; dorsal surface punctate; apex with setae sparsely distributed ( Fig. 32 ).

Genitalia: Phallobase shorter than parameres; phallobase connected to parameres by a triangular membrane on dorsum ( Figs. 38 ). Parameres goose-head-like, with a central concave area and tip rounded in lateral view; bases of parameres of lateral and dorsal branches enclosed with a trapezoidal membranous area ( Figs. 38, 39, 40, 41 ). Endophallus with slender temones in dorsum and a hemispherical lobe covered with dense punctual sensillae in distal part ( Fig. 42 ). Spiculum gastrale T-shaped.

Female. Not studied.

Diagnosis. Megistophylla grandicornis can be clearly distinguished from other Megistophylla species by the following combination of characters: antennal club composed of 5 long antennomeres, club curved vertically in apical half, length of club 2.4–2.6 times longer than basal antennomeres; head, pronotum, elytra with dorsum glabrous; pronotum with lateral margin smooth; pronotum with 7–10 long setae close to lateral margin at anterior half; epipleuron with long soft setae before apex; outer side of metatibia with completed carina; parameres goosehead-like.

Distribution. China (Chongqing, Hubei, Hunan, Guangxi, Guizhou, Jiangxi, Yunnan, Zhejiang) ( Li et al. 2016), above mentioned specimens represent the first record from Fujian Province.

Chinese name. 巨角多鳃金龟

Remarks. Unfortunately, we are unable to examine female specimens of Megistophylla grandicornis . All the specimens mentioned above were collected by light trapping, females of M. grandicornis might have negative phototactic response. The antennal club is composed of 5 antennomeres in the female, and is distinctly shorter than those in the male ( Xu et al. 2012). Megistophylla grandicornis is a severe pest in southern China. The larvae feed on the underground parts of chestnut, oak and eucalyptus; the adults feed on the foliages of chestnut, tobacco, persimmon, bamboo, pear, apple, walnut and waxberry ( Hu et al. 2010, Xu et al. 2012). The adults of the species emerge from May to June with one generation per year and overwinter as larvae in Yunnan Province ( Hu et al. 2010).

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.