Integrative taxonomy of the genus Dyscolus (Coleoptera, Carabidae, Platynini) in Ecuadorian Andes
Author
Moret, Pierre
2E194645-D255-438B-819E-A2B6C39AD699
Laboratoire TRACES (UMR 5608), CNRS, Université Toulouse 2 Jean Jaurès, Toulouse 31058, France.
pierre.moret@univ-tlse2.fr&pierre.moret@univ-tlse2.fr
Author
Murienne, Jérôme
3A6964D4-A7D6-46DB-8129-B762D14BC8F9
Laboratoire Evolution et Diversité Biologique (UMR 5174), CNRS, Université Toulouse 3 Paul Sabatier, IRD, Toulouse 31062, France.
jerome.murienne@univ-tlse3.fr
text
European Journal of Taxonomy
2020
2020-05-15
646
1
55
journal article
22092
10.5852/ejt.2020.646
c5cf0da1-13e3-4bf4-844c-9b5a9d4f6d5b
3829682
4C9F63B2-DB17-4EDB-ADEE-13AC9EFB921B
Dyscolus denigratus
(
Bates, 1891
)
Figs 45–50
Colpodes denigratus
Bates, 1891: 17
.
Dyscolus palatus
Moret, 1998: 18
.
syn. nov.
Dyscolus
(
Dyscolus
)
denigratus
–
Moret 2005: 128
.
Dyscolus
(
Dyscolus
)
palatus
–
Moret 2005: 130
.
Dyscolus denigratus
is a highly variable species, with a broad range of variation within each population regarding body size, form of the pronotum, length of the legs, and form of the apex of the male aedeagus (
Figs 45–46, 48–50
). The tree based on the COI sequences separates two clades (Fig. 2): one in the south-west part of the area of
D. denigratus
, represented in our dataset by the
Cotopaxi
and
Pichincha
populations, vs a north and north-east zone represented by the Cotacachi, Cayambe and Guamaní populations. Additionally, three species-level units are recognized through BIN analysis: the first one embraces the populations of the south-western clade, including specimens identified as
D. palatus
. The northern clade is split into two BIN units: one for the Guamaní population, and another for the Cotacachi and Cayambe populations. However, we were unable to find any morphological character that reliably reflects these divisions. According to the form of the apex of the median lobe, the Cotacachi population (
Fig. 49
) seems to be closer to the
Pichincha
population (
Fig. 50
) than to the Guamaní one (
Fig. 48
), in contradiction with the molecular results. Obviously, the phylogeny of the
denigratus
complex cannot be resolved from the COI sequences alone.
We thus take a conservative approach, with no taxonomic decision regarding the specific or subspecific status of the components of the
denigratus
complex, except for the synonymy of
Dyscolus palatus
with
Dyscolus denigratus
.
Dyscolus palatus
was described from specimens from the
Pichincha
, Atacazo and Corazón volcanoes in the Western Cordillera (
Fig. 47
). This taxon was then thought to be more closely related to
D. altarensis
(
Bates, 1891
)
than to
D. denigratus
, due to its relatively broader and shorter body. The specimen of
D. palatus
included in our analysis (COI voucher PM359-01, BOLD sequence SUM168- 18) instead suggests that
D. palatus
and
D. denigratus
are conspecific. A re-examination of the
type
series of
D. palatus
and of large series of specimens recently collected on the
Pichincha
shows that the body dimensions of the two taxa partly overlap (
Fig. 51
). Owing to the existence of these transition forms,
D. palatus
cannot be maintained as a good species and we therefore treat it as a synonym of
D. denigratus
.