Megistophylla octobracchia Gao & Li, new species (Coleoptera: Scarabaeidae: Melolonthinae) from Yunnan, China, and redescription of M. grandicornis (Fairmaire, 1891)
Author
Gao, Chuan-Bu
Author
Li, Chun-Lin
Author
Fang, Hong
text
Zootaxa
2019
2019-03-12
4565
4
515
522
journal article
28375
10.11646/zootaxa.4565.4.5
365007a3-10a0-4a7e-a27a-eac37c849690
1175-5326
2591335
6FCA0D13-6302-42B9-A21A-98EFF9F641DA
Megistophylla octobracchia
Gao & Li
,
new species
(
Figs. 1, 2
,
5–11
,
19–25
,
33–37
)
urn:lsid:zoobank.org:act:
C6D8B7D8-F81B-4E26-AEDA-90576F08B303
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
).
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.
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