Resolving the synonymy and polyphyly of the ‘ Drosophila bakoue species complex’ (Diptera: Drosophilidae: ‘ D. montium species group’) with descriptions of two new species from Madagascar
Author
Yassin, Amir
Author
Suwalski, Arnaud
Author
Raveloson Ravaomanarivo, Lala H.
text
European Journal of Taxonomy
2019
2019-06-18
532
1
26
journal article
26436
10.5852/ejt.2019.532
fbea3203-a10b-4e4f-b5f3-3d1387bc84c3
3251569
1301752E-3FD5-4F3E-A4F3-6766D18C709A
Drosophila
(
Sophophora
)
vulcana
Graber, 1957
Figs 1–2
,
8
A–B, 9A, C, E
Drosophila
(
Sophophora
)
vulcana
Graber, 1957: 309
.
Diagnosis
Male abdominal tergites T5 with a contiguous diffuse dark brown stripe, T6 light with a very faint dark stripe (
Fig. 8A
); hypandrium narrow with an elongated anterior phragma; outer paraphyses posterior margin curved; aedeagus pilosity tapering at tip (
Fig. 9A, C
); female abdominal tergites T2–T4 without a diffuse pale region on the antero-distal margins, T5 with diffusely dark stripe (
Fig. 8B
); oviscapt fourth posterior peg-like outer ovisensillum on the same axis with the third and fifth ovisensilla, with anterior ovisensilla short and thick (
Fig. 9E
).
Type material
Holotype
DEMOCRATIC REPUBLIC OF THE CONGO
•
♂
;
Kivu Province
,
Mount Bugulumiza
; 1954;
ZMUZ
.
Description
As in
Graber (1957)
for the
type
material and
Bock & Wheeler (1972)
for a strain from Mount Selinda (
Zimbabwe
).
Distribution
Democratic Republic of the Congo
(
type
),
Kenya
,
Tanzania
and
Zimbabwe
.
Remarks
The type material of
Graber (1957)
consisted of six males and six females from
Kivu Province
(
Democratic Republic of the Congo
).
Tsacas & Chassagnard (1992)
examined this material and found five males and six females (probably the male used by Graber for dissection and genitalia illustration was lost). Of the five remaining males, only one belonged to a ‘
D. montium
species group’ that
Tsacas (1984)
considered
D. ifestia
. Of the six females, five belonged to the ‘
D. montium
species group’. Two females sojourned in alcohol and lost coloration, whereas the remaining three females were pinned and had dark wings, pleurae and legs in agreement with the original description of
Graber (1957)
. For abdominal coloration, this description indicates “uniform schwarzbraune glänzende Tergite” (uniform black-brown shining tergite).
Bock & Wheeler (1972)
described a strain from Mount Selinda (
Zimbabwe
) attributed to
D. vulcana
by S. Paterson. They showed, however, the presence of two types of male genitalia in this strain.
Tsacas & Chassagnard (1992)
reanalyzed this strain and found that only one of the two types existed at the time of their examination. They concluded that the original strain consisted of two distinct species with one having subsequently gone extinct. They also suggested that male genitalia of the type of
Séguy (1938)
for
D. seguyi
corresponded to the genitalia of the surviving species in this strain. We dissected males from the strain of Mount Selinda and found that the illustration of
Tsacas & Chassagnard (1992)
of the
holotype
of
D. seguyi
lacks the partial fusion of the cercal ventral lobe (secondary clasper), characteristic of the strain of Mount Selinda. Moreover, the pale male abdominal pigmentation of the strain of
Bock & Wheeler (1972)
(
Fig. 4G
) clearly contrasts with the description of
Séguy (1938)
of
D. seguyi
: “tergites largement bordés de brun noir, dernier segment d’un noir luisant” [tergites with large brownish black stripe, last segment shiny black]. On the contrary, abdominal pigmentation of the strain of Mount Selinda corresponded to the abovementioned original description of
Graber (1957)
. Therefore, we concur with
Bock & Wheeler (1972)
for considering the strain of Mount Selinda to belong to
D. vulcana
.
Okada
et al.
(1988)
recorded this species from
Tanzania
, and
Takada
et al.
(1990)
indicated its presence in
Kenya
, suggesting its widespread distribution in East Africa. Females do not exhibit a sex-limited color dimorphism.