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
Distinguishing Female
Conostigmus
and
Dendrocerus
, and matching males and females (
Table 3
)
As discussed above, it can be difficult to distinguish
Dendrocerus
males from
Conostigmus
males; in the case of females, it can be nearly impossible. Females of both genera have similar antennal, genitalia and ovipositor characters. Females of both genera also have more similar ocellar triangle shapes and POL vs. OOL ratios than males. Characters that do occur across both male and female specimens include the presence of the sternaulus (never present in
Dendrocerus
, absent or present in
Conostigmus
), notauli posterior end (always adjacent to transscutal articulation in
Conostigmus
, but not adjacent in some
Dendrocerus
) and wing presence (wings always present and macropterous in
Dendrocerus
). However, the numerous exceptions that exist prevent these characters from being applied to all species. Other characters such as facial pit presence, as well as more subjective characters such as metapleural sulcus shape, head shape and general habitus, can be useful but are more variable and should not be used independently to make generic identifications.
It is difficult to distinguish females of
Conostigmus
and
Dendrocerus
, let alone females of different
Conostigmus
species. Even males cannot always be differentiated by somatic characters alone, as demonstrated by the morphometric analysis with the shape PCAs. This revision relies mainly on male genitalia characters, as this can be the only way to distinguish
Conostigmus
species in some cases (
Dessart, 1997a
,
1997b
;
Mikó
et al
., 2013
, 2016).
Some species do have unique combinations of somatic characters that can be used to match males and females, including
C. muesebecki
,
C. dimidiatus
,
C. erythrothorax
,
C. nigrorufus
,
C. bipunctatus
,
C. triangularis
, and
C. lepus
. We were also able to confirm the female of
C. pulchellus
based on a male specimen that exhibited the same coloration found in the female specimens, but we avoid redescribing females of
C. abdominalis
from the Nearctic, as this species can only be distinguished from
C. rosemaryae
using male genitalia characters. Several Nearctic
Conostigmus
species were described from single female
type
specimens, but because females cannot be identified to species in most cases, we consider these as
species inquirenda
. Advances in molecular taxonomy and future work rearing live
Conostigmus
males and females will shed more light on this subject, and we eagerly anticipate what will be found.