Integrative taxonomy reveals cryptic diversity in neotropical grasshoppers: taxonomy, phylogenetics, and evolution of the genus Sphenarium Charpentier, 1842 (Orthoptera: Pyrgomorphidae)
Author
Sanabria-Urbán, Salomón
Author
Song, Hojun
Author
Oyama, Ken
Author
González-Rodríguez, Antonio
Author
Castillo, Raúl Cueva Del
text
Zootaxa
2017
4274
1
1
86
journal article
32875
10.5281/zenodo.804182
c7ffebb0-4bea-4c4d-8873-96db1864f598
1175-5326
804182
27748C60-F64A-4E2C-B5CD-8DB413480DF4
Sphenarium minimum
Bruner, 1906
(http://lsid.speciesfile.org/urn:lsid:
Orthoptera
.speciesfile.org:TaxonName:36988)
Sphenarium affine
Bruner, 1906
Description.
External morphology (
Figs. 8
G, H; 9O, P): total body length ranging from
23.67 to 28.57 mm
in females and
18.05 to 24.89 mm
in males; antennae filiform, slightly shorter in females or notably longer than head and pronotum together in males; head subtriangular-elongated slightly longer than wide in females or conical notably longer than wide in males, with oval eyes in both sexes; fastigium moderately elongated, nearly half the length of interocular space in both sexes; tegmina spatula-like in both sexes; subgenital plate of males rounded moderately developed posteriorly; dorsal ovipositor valves lanceolate, notably elongated towards the apex. Male genitalia: bridge of epiphallus as long as the length of lateral plates in most cases (
Fig. 12
J-I). Ectophallus in dorsal view (
Fig. 12
J-II) with lateral borders of ramus strongly concave; basal emargination of cingulum moderately developed; interspace between apodemal plates of cingulum moderately open. Ectophallus in posterior view (
Fig. 12
K) without a conspicuous sclerotized hollow in the sheath; inflections of supraramus moderately developed with distal margins laterally directed in most cases; valves of cingulum notably small, triangular and slightly developed posteriorly (
Fig. 12
K, L). In lateral view of endophallus (
Fig. 12
J-III) pseudoarch elongated loosely joined the valves of cingulum; aedeagal valves medium sized with smooth ventral margins and moderately rounded in the apex, without apical spine (
Fig. 12
K, L); aedeagal valves and sclerites together about 1 ¼ fold the length of dorsal inflections of endophallic apodemes.
Colouration.
Ground colours vary from green, yellow or brown. Body uniformly coloured or with the following colour traits: antennae and fastigium frequently brown; lateral postocular bands frequently present, narrow and yellow; dorsomedial line generally absent, if present very narrow almost restricted to the abdomen, whitish, yellowish or pinkish; dorsal shades frequently absent, if present very narrow in head and thorax, wider in the dorsal portion of abdomen, light to dark brown; lateral shades often absent, if present very narrow, black or dark brown, almost restricted to head and abdomen; lateral bands of blotches not evident; ventral bands of pronotum often absent, if present very narrow and yellowish; mesonotum partially or entirely black; lateral whitish blotches of 1st abdominal segment sometimes evident; in most cases hind femora uniformly coloured, sometimes with lower medial area whitish or yellowish and brown knees; hind tibia frequently yellow or pale orange.
Diagnosis.
S. minimum
closely resembles
S. planum
,
S. purpurascens
,
S. tarascum
sp.n.
, and
S. zapotecum
sp.n.
in both external and genital morphology. Externally
S. minimum
only differs from the former two species by its more elongated head (in both sexes) and its lanceolate and more notably elongated dorsal ovipositor valves. Nevertheless, more conspicuous differences exist between male genital structures of all these species.
Sphenarium minimum
differs from these species by the following combination of male genital traits: ectophallus with lateral borders of ramus notably concave, valves of cingulum triangular and notably small, medium-sized aedeagal valves and moderately rounded in the apex without apical spine, and aedeagal valves and sclerites about 1 ¼ fold the length of dorsal inflections of endophallic.
Distribution.
This species is distributed in elevations ranging from approximately
1000 to 1596
m
a.s.l. in the outer slope of southern portion of the Sierra Madre Oriental in
Veracruz
,
Mexico
(
Fig. 7
A).
Material
examined.
S. minimum
:
lectotype
m
(
Fig.
8
G) from
Mexico
:
Veracruz
,
Jalapa
, XII (
O.W. Barrett
);
S. affine
:
lectotype
m
(
Fig.
8
H) from
Mexico
:
Veracruz
,
Orizaba
,
XI-1887
(
L. Bruner
).
Designation
:
Rehn
and
Hebard
(1912)
and location:
ANSP
for both
type
specimens.
We
examined only the external morphology of this
type
material.
Additional material
:
7
m
, 5
f
, from Jalapa (L76);
2
m
from Orizaba (L292),
35
m
, 26
f
, from 12 adjacent localities in
Veracruz
(Appendix
Table 5
).
Taxonomic discussion.
Bruner (1906)
originally described this species apparently based on a single male from
Jalapa
,
Veracruz
.
Bolivar (1909)
and
Hebard (1932)
recognized
S. minimum
as a valid species. Particularly, the later author proposed a closer relationship between
S. minimum
,
S. histrio
and
S. mexicanum
mainly based on their head morphology.
Boyle (1974)
also identified differences in head morphology and colouration patterns between
S. minimum
and
S. purpurascens
. However, this author only recognized the former taxon as a subspecies of the later,
S. purpurascens minimum
, principally based on the similarity between their epiphallic and ectophallic structures. Recently,
Pedraza-Lara
et al.
(2015)
and
Sanabria-Urbán
et al.
(2015)
proposed again the re-establishment of
S. minimum
as valid species based principally on genetic evidence. In this study we found that despite the notable similarity in the male genitalia between
S. minimum
and
S. purpurascens
the former taxon shows a unique combination of external and male genitalia characters, a well-supported monophyly (
Fig. 2
), and a well-separated geographic distribution from
S. purpurascens
. All these lines of evidence support the recognition of
S. minimum
as a valid species.
Sphenarium affine
was only briefly described by
Bruner (1906)
apparently based on one female and male from Orizaba,
Veracruz
. Originally,
Bruner (1906)
recognized a close relationship between
S. affine
and
S. minimum
, only differentiating the former from the later in highly variable traits of head morphology. Later
S. affine
was synonymised within
S. marginatum
(
Hebard 1932
)
, despite the notable external differentiation between both taxa. Posteriorly,
Boyle (1974)
synonymized
S. affine
within
S. p. minimum
.
In this study we examined several specimens collected in
type
localities of
S. minimum
and
S. affine
; which were practically similar among them in their male genital morphology. Therefore, we also recognise
S. affine
as a synonym of
S. minimum
.