A Taxonomic Revision of Nearctic Conostigmus (Hymenoptera: Ceraphronoidea: Megaspilidae)
Author
Trietsch, Carolyn
Author
Mikó, István
Author
Ezray, Briana
Author
Deans, Andrew R.
text
Zootaxa
2020
2020-06-15
4792
1
1
155
journal article
21681
10.11646/zootaxa.4792.1.1
dd8ef826-0c0f-4261-b127-1d1afa7f5601
1175-5326
3895976
326F6A15-216E-439A-AD59-3CDF7551D3F6
Conostigmus canadensis
(
Ashmead, 1888
)
Figs. 18
,
19
Species Comments and History.
Ashmead (1888)
described this species from a single female specimen as part of the genus
Eumegaspilus
, characterized by the females being wingless or having reduced wings.
Ashmead (1893)
redescribed the species, transferred it to
Megaspilus
and designated
C. erythrothorax
as the
type
species for
Eumegaspilus
. For
C. canadensis
, Ashmead
keyed out the female, distinguishing it from other females based on its reduced wings, cuticular sculpture and color differences (1893).
Harrington (1900)
recorded four more female specimens of
C. canadensis
collected with Harrington’s
C. ottawensis
specimens, noting that these four specimens might be a variety of
C. ottawensis
.
We found these four specimens at the CNC, all bearing labels reading “
Megaspilus canadensis
=
ottawensis
Ashm.
|| W. H. Harrington Collection”.
Harrington (1900)
also recorded the existence of a fifth specimen, which we found at the CNC, bearing only a determination label reading “
Megaspilus canadensis
”. All of these specimens are females in poor condition (damaged and badly glued, obscuring characters) and none were collected with the
type
. These specimens may not match each other, let alone the
type
of
C. canadensis
. One female had the preoccipital furrow not reaching the ocellar triangle (the
type
has the preoccipital furrow ending inside the ocellar triangle). Further work must be done to verify whether these specimens are the same species. These five specimens were not databased.
FIGURE 17.
Conostigmus californicus
(
Ashmead, 1893
)
male lectotype (USNMENT01339748). A. Dorsal view. B. Dorsal view of the frons. C. Lateral view.
Kieffer (1909)
transferred
C. canadensis
from
Megaspilus
to the genus
Conostigmus
.
Kieffer (1914)
then redescribed and keyed out the female, distinguishing it from other female
Conostigmus
by its reduced wings and coloration.
Muesebeck and Walkley (1951
,
1956
) reconsidered
C. canadensis
as the
type
of
Eumegaspilus
and consider
Eumegaspilus
as a synonym of
Conostigmus
.
Muesebeck and Walkley (1956)
justified this by noting that
C. erythrothorax
was not in the original description of the genus.
Dessart and Cancemi (1987)
consider
C. canadensis
to be the
type
species of the subgenus
Eumegaspilus
. They also note that
C. canadensis
is probably cosmopolitan (
Dessart and Cancemi, 1987
).
The female
type
is present at the USNM in the same condition as noted in
Masner and Muesebeck (1968)
.
Dessart and Cancemi (1987)
suggested that this species could be synonymous with
C. lativentris
. While this specimen bears a strong resemblance to the female
types
of
C. lativentris
at the NHMUK and HNHM (wings reduced or absent, sternaulus present and elongate, facial pit present, postocellar carina present, preoccipital furrow present, median process on the intertorular carina present and acute, axillular carinae present), there are differences in the sculpturing. The
type
at the NHMUK has foveolate sculpturing on the frons and mesosoma; the
type
at the HNHM does not have foveolae but has rugose sculpturing present on the frons and mesosoma; and the
type
at the USNM has smooth sculpturing on the frons and mesosoma. Though all three specimens have rugose sculpturing on the apex of the head around the ocelli, the
types
at the HNHM and NHMUK have crenulate sternauli, whereas the
type
at the USNM has a smooth sternaulus. It is possible that these differences could be attributed to size, nutrition and other factors, and that they could be the same species, but further evidence is needed to confirm this.
Conostigmus lativentris
is also only known from the Palearctic, whereas
C. canadensis
is only known from the Nearctic.
Both
C. canadensis
and
C. lativentris
are only known from female specimens. Until the discovery of males or more females, or until the five female specimens at the CNC can be further studied, we cannot confirm if
C. canadensis
and
C. lativentris
are the same species. We consider them separate species at this time, and we regard
C. canadensis
as a
species inquirenda
.
Material Examined.
Lectotype
female:
CANADA
: USNMENT01339753 (
USNM
).