Review of the Madagascan Orphninae (Coleoptera: Scarabaeidae) with a revision of the genus Triodontus Westwood
Author
Frolov, Andrey V.
Author
Montreuil, Olivier
Author
Akhmetova, Lilia A.
text
Zootaxa
2016
4207
1
1
93
journal article
37549
10.11646/zootaxa.4207.1.1
cef35771-ff95-4a41-9af6-196dea899a64
1175-5326
200444
F2875582-31E2-496F-AEEF-1D657DD86C33
Triodontus alticola
Paulian, 1977
(
Figs. 41
A–H)
Triodontus alticola
Paulian, 1977
: 1215
.
Triodontus maroantsetrae
Paulian, 1977
: 1219
,
new synonym
Type
material examined.
Triodontus alticola
.
Holotype
(
Figs. 41
C, D), male, “
Madagascar
Ambohitsitondrona [
Toamasina Province
]
XI-1949
Michel
/
Triodontus alticola
n. sp.
R. Paulian
det. /
TYPE
” (
MNHN
).
Paratypes
: two females with the same locality and date label (
MNHN
)
;
two males and two females with the same locality label but the date “
XII-52
” (
MNHN
)
;
one male, “
Madagascar
Sambava [
Antsiranana Province
] XI [...]
Vadon
!” (
MNHN
)
;
one male, “
Madagascar
Ambodivoangy [
Toamasina Province
]
I.1950
Vadon
!” (
MNHN
)
.
Triodontus maroantsetrae
.
Holotype
, male, “
Madagascar
Ron Maroantsetra
XII.35
Vadon Antakotako
/
MUSEUM
PARIS
1938
J. Vadon
et
E. Lebis
/
TYPE
/
Triodontus
maroantsetrae
n. sp.
R. Paulian
det.” (
MNHN
)
.
Additional material examined.
MADAGASCAR
:
Toamasina
:
two males, “
Madagascar Ambohitsitondrona
II-1948
Michel
[
15°34′59″S
,
50°01′00″E
]” (
MNHN
)
;
one male, “
Madagascar
Ambodivoangy [
15°17′49″S
,
49°36′47″E
]
I.1946
Vadon!” (
MNHN
)
; one male, same label but
XII.1947
(MNHN);
one female, “
Madagascar
Antakotako [
15°19′00″S
,
49°48′00″E
]
II.1946
Vadon!” (
MNHN
)
;
one male, “
Madagascar
Est distr. Mananara -
N. Antanambe Vadon
et Peyrieras [
Mananara District
, Antanambe,
16°25′59″S
,
49°51′00″E
]” (
MNHN
)
;
four males, one female, “
Madagascar
Ambohitsitondrona
I-1946
Vadon
! [
15°34′59″S
,
50°01′00″E
]” (
MNHN
)
;
one male, “
Madagascar
Ambohitsitondrona
25-I-1948
Michel [
15°34′59″S
,
50°01′00″E
,
25.I.1948
]” (
MNHN
)
;
one male, one female, “
Madagascar
Ambohitsitondrona
X-1947
Vadon
! [
15°34′59″S
,
50°01′00″E
]” (
MNHN
)
.
Diagnosis.
Triodontus alticola
can be separated from other species of the genus by the characteristic shape of the parameres having the outer lobes long, curved downward and inward; with more-or-less separated, strongly sclerotized lateral parts and membranous, overlapping medial parts; and without lateral notches.
Description. Male.
Color of head, pronotum, and elytra dark brown, legs, antennae, and underside of the body slightly paler (
Figs. 41
A, C).
Frontoclypeus slightly convex anteriorly, obtusely rounded laterally, anterior margin setose in dorsal view. Eyes relatively small (diameter slightly smaller than the distance between eye and gula in ventral view), incompletely divided by canthus into small, dorsal and large, ventral parts. Frontoclypeus with tubercles mediad of each eye and with a horn in center. The horn is longer than width of the head, acutely rounded apically, somewhat curved caudally, with slightly flattened anterior side and slightly rugose posterior side.
Pronotum with a bulge medially in center, with excavations each side of bulge, and with 2 ridge-shaped tubercles laterally of each excavation. The median bulge with 2 distinct tubercles and somewhat excavated between the tubercles. Lateral margins with wide border bearing a row of brown setae. Anterior margin with wide, smooth border, almost not sinuate medially. Posterior margin with fine border, not crenulate, punctate with a few narrow, longitudinal punctures. Surface of most pronotum punctate with minute, feebly visible puctures.
Scutellum rounded apically, visible part is about 1/15 length of elytra.
FIGURE 41.
Triodontus alticola
, holotype male (C, D, E, F), male (A), female (B). Habitus in dorsal view (A, B, C), aedeagus in lateral view and parameres in dorsal and ventral view (E), labels of holotype (D), internal sac of aedeagus (F), abdomen (G), distributional records (H).
Elytra convex, with distinct humeral humps. Maximum width approximately at middle. Elytra with 10 striae; stria 1 (sutural) distinct, other feebly marked with small punctures. Intervals with minute punctures, almost smooth. Base of elytra with an irregular row of coarse punctures.
Abdominal sternite 8 medially deeply sinuate, without tubercles or concavities in middle (
Fig. 41
G).
Parameres (
Fig. 41
E) with outer lobes long, curved downward and inward; with more-or-less separated, strongly sclerotized lateral parts and membranous, overlapping medial parts; and without lateral notches. Internal sac of aedeagus with a hoof-shaped sclerite (
Fig. 41
F).
Female.
Females (
Fig. 41
B) differ from males in having a protibial apical spur; absence of head and pronotum armature including tubercles mediad of each eye; and longer abdominal sternites including 6th sternite, which is evenly rounded apically.
Variation.
The pronotal and head armature of males is less developed in some specimens. Body length of examined specimens varied from 8.8–12.0 mm (males) and from 9.0–11.0 mm (females).
Distribution.
This species is known from a few localities in the northeastern part of the island, mostly north of Antongil Bay (
Fig. 41
H).
Remarks.
Triodontus maroantsetrae
was described from one male specimen from Antakotako. Comparison of this specimen with the
type
series of
T. alticola
has shown that they have similar shape of the parameres. The only difference is the feebly developed frontoclypeal horn and almost absent ridges and tubercles on the pronotum in the
holotype
of
T. maroantsetrae
. We believe all these specimens fall within the limits of allometric variability of one species, therefore the new synonymy is here proposed.