Three new species of Rhaphium Meigen, 1803 from mangroves in Hong Kong (Diptera: Dolichopodidae: Rhaphiinae)
Author
Grootaert, Patrick
Author
Taylor, Christopher
Author
Guénard, Benoit
text
European Journal of Taxonomy
2019
2019-07-30
540
1
21
journal article
26099
10.5852/ejt.2019.540
2d33c675-52ef-4bf7-a1d0-884df2d2e8c4
3357392
88E89839-8631-490D-92F8-526A65F387A3
Rhaphium spinulatum
sp. nov.
urn:lsid:zoobank.org:act:
5CFE7569-8A05-4D7B-AC60-5AA30F5A0C87
Figs 3–4
Diagnosis
Small species with a long postpedicel, almost 6 × as long as wide, biseriate acrostichals, five pairs of dorsocentral bristles, simple cerci and surstyli apically simple. Scape and pedicel brown like postpedicel. Fore tarsomere 1 ventrally not produced, bearing a pair of curved apical spines. Surstylus dark brown.
Etymology
The new species is named after the distinctive spinules on the apex of the first tarsomere of the fore leg.
Material examined
Holotype
HONG KONG
•
♂
;
Sam A Tsuen
(5
AM1
);
22.51534° N
,
114.27121° E
;
11–27 Dec. 2017
;
C. Taylor
and
U. Chang
leg.; muddy back mangrove;
RBINS
.
Paratypes
HONG KONG
•
2 ♂♂
,
1 ♀
; same collection data as for holotype;
RBINS
•
3 ex.
;
Tsim Bei Tsui
(
Sha Kiu Tsuen
) (9EM1);
22.48902° N
,
113.99832° E
;
31 Oct.–15 Nov. 2017
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
•
9 ex.
;
To Kwa Peng
(29M1);
22.42863° N
,
114.33314° E
;
29 Nov.–5 Dec. 2017
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
•
22 ex.
;
Ho Chung
(
Nam Wai
) (38
AM1
);
22.35347° N
,
114.25622° E
,
4–18 Dec. 2017
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
•
13 ex.
;
Ho Chung
(38
BM1
);
22.35366° N
,
114.25207° E
;
4–18 Dec. 2017
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
•
242 ex.
;
Tai Tan
(28M1);
22.43857° N
,
114.33327° E
,
5–19 Dec. 2017
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
•
2 ♂♂
,
2 ♀♀
; same collection data as for preceding; barcoded; HKU
•
7 ex.
;
Wong Chuk Wan
(34M1);
22.39563° N
,
114.28617° E
;
5–19 Dec. 2017
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
•
2 ex.
;
Sam
A
Tsuen
(5
AM1
);
22.51534° N
,
114.27121° E
;
11–27 Dec. 2017
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
•
91 ex.
;
Sam
A
Chung
(5
BM1
);
22.50829 N
,
114.27248° E
;
11–27 Dec. 2017
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
•
34 ex.
;
Sai Keng
(40M1);
22.42041° N
,
114.26796° E
;
18 Dec. 2017
–
2 Jan. 2018
;
C. Taylor
and
U. Chang
leg.; barcoded;
RBINS
.
Barcodes
The barcodes below can be copy/pasted into a fasta file in order to compare with other species.
>doli_HKC0000197_Kareen-Nabilah_
INTRN
223_
HongKong
_
31Dec
9999_20180820 male Ho Chung (Nam Wai) 38
AM
1 GAATAAATGTTGATATAGTACAGGGTCTCCTCCTCCTGCGGGGTCGAAGAATGATGTATTT AAATTACGATCTGTTAATAACATAGTAATAGCTCCGGCTAGTACTGGTAATGATAATAATA ATAGAATTGCTGTAATTACTACAGATCAAACAAATAAGGGCATTCGGTCAAGAGTAATTCC AGTGGATCGTATATTAATTACTGTTGTAATAAAATTTACTGCCCCTAAAATTGATGAAATACC GGCAAGATGTAAAGAAAAAATAGCTAAATCAACAGAGGCACCACCATGAGCAATACCTGC AGACAGA
>doli_HKC0000137_Kareen-Nabilah_
INTRN
222_
HongKong
_
31Dec
9999_20180820 female Tai Tan 28M1 GAATAAATGTTGATATAGTACAGGGTCTCCTCCTCCTGCGGGGTCGAAGAATGATGTATT TAAATTACGATCTGTTAATAACATAGTAATAGCTCCGGCTAGTACTGGTAATGATAATAAT AATAGAATTGCTGTAATTACTACAGATCAAACAAATAAGGGCATTCGGTCAAGAGTAATT CCAGTGGATCGTATATTAATTACTGTTGTAATAAAATTTACTGCCCCTAAAATTGATGAAATA CCGGCAAGATGTAAAGAAAAAATAGCTAAATCAACAGAGGCACCACCATGAGCAATACCT GCAGACAGA
Description
Male
MEASUREMENTS. Body:
2–2.1 mm
long; wing:
2.1–2.4 mm
long.
HEAD. Face narrow, parallel-sided, a little wider than postpedicel. Antenna uniformly brown. Postpedicel almost 6 × (5.8) as long as wide; arista short (a third of the length of the postpedicel); basal aristal segment short. Palpus yellowish, with a small pale brown bristle. Vertical bristles twice as long as ocellars. Postoculars all whitish, uniseriate above, multiseriate and densely set below.
THORAX. Acrostichals short, biseriate, rows close together, present on basal ⅔ of mesonotum. Five long dorsocentrals equally long, with a short bristle in front. A pair of long scutellars.
LEGS. Yellow, but base of fore coxa brown, mid and hind coxae anteriorly brownish, hind leg with knee brown (tip of femur and base of tibia). Fore tarsus with tarsomeres 2–4 brown above, apical tarsomere entirely brown. Mid and hind leg with only tarsomeres 4 and 5 brown.
FORE LEG. Coxa with long pale bristles (
Fig. 3
). Femur with three preapical posteroventral bristles. Tibia with a long dorsal preapical and a ventral row of bristles, nearly as long as tibia is wide. Tarsomere 1 with a ventral row of bristly hairs (
Fig. 4A
); its tip is ventrally not produced and bears a pair of curved apical spines.
MID LEG. Coxa with white bristles anteriorly and a white exterior. Femur with a preapical anterior, one preapical posteroventral and two distinct posteriors. Tibia with two short ad and an apical crown of short bristles.
HIND LEG. Coxa with a white exterior bristle. Tibia with a short ad and pd in basal third and a short ad and pd in apical third; apical crown with short bristles.
WING. Brownish tinged with brown veins (
Fig. 3
). Squama white with long white cilia. Haltere white.
ABDOMEN. Same colouration as thorax, venter paler, with minute hairs. Only tergite 1 with long marginal bristles.
MALE TERMINALIA (
Fig. 4
). Surstylus dark brown, with a pointed tip (
Figs 3
,
4C
). Cercus whitish, very long and thin, its tip reaching beyond tip of sternite 3.
Female
MEASUREMENTS. Larger than male. Body:
2.5–2.6 mm
long; wing
2.3–2.6 mm
long.
HEAD. Face parallel-sided, wide, nearly 4 × as wide as postpedicel. Scape and pedicel brown (not so dark as postpedicel); postpedicel black, elongate triangular, shorter than in male, 4–4.5 × as long as wide, about 1.5 × as long as arista.
Fig. 3.
Rhaphium spinulatum
sp. nov.
, holotype, ♂, habitus (RBINS). Scale bar: 1 mm. (Photo credit Ms Camille Locatelli)
LEGS. Fore coxa with long white bristles over entire posterior margin (shorter in male). Bristles of posteroventral row in apical half of fore tibia less distinct than in male. Fore tarsomere 1 without apical spines.
Remarks
See under
R. hongkongense
sp. nov.
for characters distinguishing this species from
Rhaphium
outside of
Hong Kong
.
Rhaphium spinulatum
sp. nov.
is smaller than
R. hongkongense
sp. nov.
The basal aristal segment is longer. The tip of fore tarsomere 1 is not produced but bears a pair of distinct apical spinules. Coxae 2 and 3 both bear a white exterior bristle. The surstylus is black, with a slender, pointed tip.
Fig. 4.
Rhaphium spinulatum
sp. nov.
, holotype, ♂ (RBINS).
A
. Fore leg, posterior view.
B
. Fore coxa.
C
. Epandrium, lateral view.
D
. Epandrium, ventral view.
E
. Epandrium with cerci, ventral view. Scale bars: 0.1 mm.
Discussion of the systematic position
Rhaphium hongkongense
sp. nov.
and
R. spinulatum
sp. nov.
both have a long postpedicel, respectively 5 and 6 × as long as wide, a simple arista, 5 dc, and a simple long elongate cercus not bifurcate and lacking a bundle of apical bristles.
Tang
et al.
(2016)
and
Qilemoge
et al.
(2019)
give an overview of the attempts to classify the species of
Rhaphium
into species groups (
Naglis 2009
;
Naglis & Grootaert 2011
;
Negrobov & Grichanov 2010
).
Rhaphium hongkongense
sp. nov.
and
R. spinulatum
sp. nov.
are close to the
R. bilobum
group, defined by
Tang
et al.
(2016)
in having the postpedicel of the antenna at least 6 × as long as wide, the arista as long as the width of the postpedicel, and 5 dc. However, in species of this group, the cercus of the male genitalia is bi-foliate, with two simple lobes, whereas
R. hongkongense
sp. nov.
and
R. spinulatum
sp. nov.
have simple cerci.
The two new species are more plausibly classified in the
R. crassipes
group sensu
Negrobov & Grichanov (2010)
, which they resemble in the basic structure of the surstylus, epandrial lobe and cercus, though they differ from other species of the group, which have the male tarsomeres 4 and 5 of the mid leg black, dilated and dorsoventrally flattened. Despite this last distinction,
R. hongkongense
sp. nov.
and
R. spinulatum
sp. nov.
are very similar in the structure of the male terminalia to
R. johnrichardi
Negrobov & Grichanov, 2010
, described from the Sikhote Alin reserve in Promorsky Krai (Far East
Russia
).