The Higher Classification of the Ant Subfamily Ponerinae (Hymenoptera: Formicidae), with a Review of Ponerine Ecology and Behavior
Author
Schmidt, C. A.
Author
Shattuck, S. O.
text
Zootaxa
2014
2014-06-18
3817
1
1
242
journal article
5350
10.11646/zootaxa.3817.1.1
d66f1b27-5891-4fa5-96e0-f75cb3ec2445
1175-5326
10086256
A3C10B34-7698-4C4D-94E5-DCF70B475603
Myopias
Roger
Fig. 18
Myopias
Roger, 1861: 39
(as genus). Type-species:
Myopias amblyops
Roger, 1861: 39
; by monotypy.
Trapeziopelta
Mayr, 1862: 715
(as genus in
Ponerinae
[Poneridae]). Type-species:
Ponera maligna
Smith, F., 1861: 44
; by monotypy.
Willey & Brown, 1983: 249
(
Trapeziopelta
as junior synonym of
Myopias
).
Bradyponera
Mayr, 1886: 362
(as genus). Type-species:
Ponera nitida
Smith, F., 1861: 45
(junior primary homonym in
Ponera
, replaced by
Myopias mayri
[Donisthorpe, 1932]); by monotypy.
Willey & Brown, 1983: 249
(
Bradyponera
as junior synonym of
Myopias
).
Myopias
is a moderately large genus (35 described species) restricted to Southeast Asia and
Australia
. Relatively little is known about its habits, but at least some are specialist predators of millipedes.
Diagnosis.
Workers of
Myopias
are distinctive and unlikely to be mistaken for any other genus. Diagnostic characters of the genus (in combination) include: linear mandibles, blunt medial clypeal projection (absent in some species), round propodeal spiracles, nodiform petiole, strong gastral constriction, and simple tarsal claws. The clypeal projection and simple tarsal claws separate
Myopias
from
Leptogenys
, the morphologically most similar (and phylogenetically closest) genus.
Buniapone
and
Paltothyreus
also have blunt medial clypeal projections, but they differ in many other characters and are unlikely to be confused with
Myopias
.
Synoptic description.
Worker.
Small to large (TL
2.8–16.9 mm
) ants with the standard characters of
Ponerini
. Mandibles usually narrow and moderately curved (triangular in
M. delta
), with only a few teeth, often without a distinct basal angle, and with a strong basal groove. Clypeus very shallow, the frontal lobes reaching or surpassing the anterior clypeal margin, which usually has a small blunt anterior projection. Eyes very small to moderate in size (rarely absent), located far anterior of the head midline. Mesopleuron not divided by a transverse groove (though sometimes with a row of foveae giving the impression of a groove). Metanotal groove shallow to deep. Propodeum broad dorsally. Propodeal spiracles small and round. Metatibial spur formula (1s, 1p). Petiole nodiform, widening posteriorly and dorsally. Gaster with a strong girdling constriction between pre- and postsclerites of A4. Presence of stridulitrum on pretergite of A4 variable. Head and body foveolate or smooth and shining, sometimes with lateral striations on the mesosoma. Head and body with scattered pilosity and little to no pubescence. Color variable, yellow to black.
Queen.
Similar to worker but usually slightly larger (sometimes smaller, as in
M. chapmani
), alate and with the other caste differences typical for ponerines (
Willey & Brown, 1983
). Ergatoid queens occur in at least some species.
Male.
Undescribed and apparently unknown.
Larva.
Larvae of some
Myopias
species
have been described by
Wheeler & Wheeler (1964
,
1976
).
Geographic distribution.
The range of
Myopias
extends from
Sri Lanka
in the west and
China
in the north to
Australia
and
Tasmania
, with the greatest species diversity in
Indonesia
and New
Guinea
(
Willey & Brown, 1983
).
FIGURE 18.
Worker caste of
Myopias chapmani
: lateral and dorsal view of body and full-face view of head (CASENT0172093, April Nobile and www.antweb.org); world distribution of
Myopias
.
Ecology and behavior.
Myopias
is a poorly known genus, probably due to its cryptic nesting and foraging habits. Most of what is known about its ecology and behavior comes from anecdotal observations. Nests are generally constructed in rotting wood, though some species are subterranean nesters (
Wheeler, 1923b
;
Willey & Brown, 1983
). Reported colony sizes are typically less than
100 workers
, and often much less (
Wilson, 1959a
;
Willey & Brown, 1983
;
Gobin et al, 2006
). At least some species are polygynous, and ergatoid queens (in conjunction with normal dealate queens) occur in at least two species (
M. concava
and an undescribed Indonesian species;
Willey & Brown, 1983
;
Gobin
et al.
, 2006
). Workers of
M. emeryi
are obligately sterile (
Gobin
et al.
, 2006
). Males have apparently never been reported for any
Myopias
species
, which could simply be a reflection of the paucity of observations of any kind for this genus, or may suggest an unusual reproductive strategy. The feeding habits of most species are unknown, but some species are specialist predators of millipedes (
Wilson, 1959a
;
Willey & Brown, 1983
) and
M. delta
is a specialist predator of ants (especially myrmicines but also other ponerines).
Gobin
et al.
(2003b)
identified subepithelial glands in
M. emeryi
and
M. maligna
which may function in hydrocarbon production. Abdominal glands within a number of
Myopias
species
were examined by
Billen
et al.
(2013)
, leading to the discovery of several glands which were previously unknown in ants.
Phylogenetic and taxonomic considerations.
Myopias
was erected by
Roger (1861)
to house his newly described species
M. amblyops
. Except for a brief provisional synonymy under
Pachycondyla
(
Brown, 1973
;
Snelling, 1981
),
Myopias
has always been treated as a distinct genus.
Emery (1911)
placed the genus in his subtribe
Plectroctenini
, based on very weak characters (sculpturing, pubescence, and the presence of a pectinate spur on the meso- and metatibiae).
Willey & Brown (1983)
synonymized the genus
Trapeziopelta
and its junior synonym
Bradyponera
under
Myopias
.
We continue to treat
Myopias
as a distinct genus, based on both molecular and morphological data.
Schmidt's (2013)
molecular phylogeny of
Ponerinae
places
Myopias
with strong support in the
Odontomachus
group, probably as sister to
Leptogenys
, though sister relationships to
Mesoponera
(
s.s.
) or
Leptogenys
+
Mesoponera
cannot be rejected.
Emery (1911)
separated
Myopias
and
Trapeziopelta
based on characters of the clypeus (in
Trapeziopelta
the clypeus has a medial blunt anterior projection, which is lacking in
Myopias
s.s.
) and mandibular teeth.
Myopias
(
s.s.
) was restricted to a few small hypogeic species, while
Trapeziopelta
was considered to include most of the taxa now included in
Myopias
. Though
Schmidt (2013)
did not have molecular data for any species of
Myopias
s.s.
, we tentatively agree with the synonymy of these genera by
Willey & Brown (1983)
. It seems likely that either
Trapeziopelta
represents a distinct clade within
Myopias
(with the clypeal projection being an apomorphy of this group), or that the presence of the clypeal projection is plesiomorphic and was subsequently lost in a handful of species which evolved more cryptic habits (perhaps several times independently). It will be necessary to obtain molecular data for
M. amblyops
or another member of
Myopias
(
s.s.
) in order to test these hypotheses. It is also possible that
Myopias
and
Trapeziopelta
will prove to be unrelated lineages, though we do not think this is likely.