Two new species of Megistophylla Burmeister (Coleoptera: Scarabaeidae: Melolonthinae) from Taiwan, with notes on the genus
Author
Li, Chun-Lin
Author
Yang, Ping-Shih
Author
Wang, Chuan-Chan
text
Zootaxa
2016
4126
2
240
250
journal article
38797
10.11646/zootaxa.4126.2.4
46cf6acd-87dc-4165-80fa-e2b5330cd74c
1175-5326
258598
54F4A01E-2BB2-4802-9B93-8593DA846008
Megistophylla xitoui
Li & Wang
,
new species
Figs. 2
,
5–6
,
8
,
11–12
.
Holotype
male
(
Fig. 2
). Body length
18.5 mm
; width across humeri
8.8 mm
. Dorsal color blackish brown; venter and legs moderately shiny. Basal antennomeres reddish brown, antennal clubs blackish brown. Dorsum overall setiferous; setae tiny (high magnification for observation required); setae on disc of pronotum and elytra far smaller than diameter of puncture with exception of a row of long, sparse setae at base of head, anterior and posterior margins of pronotum, base of elytra, and scutellum, respectively; long setae brown in color with length 1–7 times longer than diameter of puncture; long setae varied in appearance.
Head:
Surface densely rugopunctate, puncture large. Clypeus (
Fig. 5
) with apex distinctly bilobed, anterior margin moderately reflexed, narrowed at base. Clypeofrontal suture clearly defined. Frons moderately raised. Basal carina slightly crescent, strongly raised. Antenna with 10 antennomeres, antennal club with 6 antennomeres, length of club subequal to basal antennomeres 1-4 combined, first antennomere of club slightly shorter than remaining antennomeres of club; fourth basal antennomere greatly enlarged.
Thorax:
Pronotum widest at middle, anterolateral angles (
Fig. 5
) strongly protuberant with basolateral angles obtuse, basal half of lateral margin coarsely serrate; lateral declivities with weak gibbosity at middle; anterior margin completely beaded with basal margin smooth; punctures same as those on clypeus, rarely confluent; punctures unevenly distributed along midline (
Fig. 6
). Scutellum triangular in shape, with a puncture bearing a long seta (
Fig. 6
). Prosternal process flat, weakly bilobed in shape.
Elytra:
Discal surface densely rugopunctate, densely confluent at sides of suture; sutural costa gradually broadening apically, densely punctate at margins of costa, rugopunctures strongly and transversally developed over sutural costa, costa becoming flat at apex.
Abdomen
: Pygidium wider than long; surface with setiferous punctures in uneven distribution, tiny setae same as those of elytral disc. Sternites 1–2, 5–6 with surface densely punctate; sternites 3–4 with sparser setiferous punctures; setae on sternites 3–4 tiny, intermixed on sternites 5–6 with much longer setae.
Legs
: Protibia tridentate. Protarsomeres 2–3 (
Fig. 8
) with setae sparsely distributed at apices. Surface of profemora and mesofemora moderately distributed with hair-like, long setae; setae on metafemora shorter and more robust, metafemora slightly broadened at middle. Metatibia with upper apical spur reaching basal one-third of metatarsomere 2; lower apical spur slightly shorter than upper spur.
Genitalia
: Parameres in lateral view with central concave area concentrically wrinkled densely, apical upper margin smooth with tip gradually narrowed apically (
Fig. 11
); upper margin of parameres gradually swollen apically at one-fourth (
Fig. 12
).
FIGURES 9–12.
Parameres of
Megistophylla
. (9, 11, lateral view; 10, 12, dorsal view). 9–10.
Megistophylla formosana
new species
; 11–12.
Megistophylla xitoui
new species
. Scale bar = 1.0 mm.
FIGURE 13.
Distribution map of
Megistophylla
species in Taiwan:
Megistophylla formosana
(open circle),
Megistophylla xitoui
(open triangle).
Female
. Unknown.
Variation.
Body length
17.5–20.9 mm
; width across humeri
8.4–9.1 mm
.Dorsal body color mainly black, rarely dark reddish brown; pronotum with anterolateral angles moderately to strongly protuberant, punctures rarely evenly distributed; scutellum usually impunctate or with less than 10 punctures, punctures sometimes with long setae; elytral sutural costa sometimes not transversally rugopunctate over costa.
Diagnosis.
Megistophylla xitoui
is morphologically most close to
M
.
formosana
and can be distinguished from the later by its distinctly black body color (mainly rufotestaceous to dark reddish brown in
M
.
formosana
); punctures usually unevenly and sparsely distributed along midline of pronotum (usually evenly and densely distributed in
M
.
formosana
); scutellum usually impunctate or with less than 10 punctures (usually exceeding 10 punctures in
M
.
formosana
); protarsomeres 2–3 with setae sparsely distributed at apices (with dense setae aggregated at apices in
M
.
formosana
) and apical upper margin of parameres smooth with tip gradually narrowed apically (distinctly swollen with tip broadly rounded in
M
.
formosana
).
Type
material.
Male
holotype
and
17 male
paratypes
. The male
holotype
is pinned and with the following information on the label: “C.
Taiwan
: Nantou, Bird Watching Trail, Xitou,
120.47E
,
23.40N
, alt. ca.
1,250m
, by FIT,
5/Mar-9/Apr/2013
, collr. C. -L. Li”. The
holotype
is deposited at the National Natural Science Museum, Taichung,
Taiwan
.
Paratypes
: Three males with the same data as
holotype
in
CCLI
; same locality as
holotype
, “
25/ Mar-27/Apr/2014
” (
1 male
,
CCLI
); same locality, “
7/May-15/Jun/2015
” (
1 male
,
CCLI
); “C.
Taiwan
: Nantou, Fong Hwan Shan, by FIT,
120.48E
,
23.39N
, alt. ca.
1,800 m
,
10/April-23/May/2013
, collr. C.-L. Li” (
1 male
in
ZMHB
;
2 males
in
BMNH
;
1 male
in
MTD
;
1 male
in
TFRI
;
1 male
in
CMNC
;
2 males
in
CCLI
); same locality, “
27/Apr-26/May/2014
” (
1 male
in ZNS,
3 males
in
CCLI
).
Distribution.
Central
Taiwan
(
Fig. 13
).
Etymology.
The specific name refers to the
type
locality, Xitou, a mid-elevated (approximately
1250–1800 m
) humid throughout the year valley in central
Taiwan
.
Chinese name:
溪頭脊頭多鰓金龜
Remarks.
This new species is only known from the
type
locality. The
type
locality is approximately
15 km
south of a
M
.
formosana
locality (approximately
600 m
in elevation), without any significant geographic barrier between these localities. Interestingly, elevation is probably not an important factor separating these species because
M
.
formosana
is found from
600–1440 m
, which partly overlaps the known elevation of
M. xitoui
. More field investigations are needed to see if these species of
Megistophylla
are sympatric in central
Taiwan
.