Species review of the genus Gnypeta Thomson from Canada, Alaska and Greenland (Coleoptera, Staphylinidae, Aleocharinae): systematics, bionomics and distribution
Author
Klimaszewski, Jan
urn:lsid:zoobank.org:author:
Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec, QC, Canada & C 136 Eddc & A- 86 C
Author
Savard, Karine
urn:lsid:zoobank.org:author:
Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec, QC, Canada & C 136 Eddc & A- 86 C
Author
Pelletier, Georges
urn:lsid:zoobank.org:author:
Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec, QC, Canada & C 136 Eddc & A- 86 C
Author
Webster, Reginald
24 Millstream Drive, Fredericton, NB, Canada & F-
text
ZooKeys
2008
2008-09-04
2
2
11
84
journal article
10.3897/zookeys.2.4
142a25ed-47c3-4361-bc24-6f1b3e8dba5c
1313–2970
576410
664C49F1-5384-43C4-8BF1-CE76AC11D32E
Genus
Gnypeta
Thomson
urn:lsid:zoobank.org:act:
8297AF32-F721-495A-9B8B-97726265E3DE
Gnypeta
Thomson 1858: 33
;
Moore and Legner 1975: 421
;
Seevers 1978: 83
;
Blackwelder 1952: 173
;
Ashe 2001: 363
;
Smetana 2004: 489
.
Type
species:
Homalota labilis
Erichson 1839
(=
Bolitochara carbonaria
Mannerheim 1830
).
Euliusa
Casey 1906: 215
;
Moore and Legner 1975: 421
;
Seevers 1978: 83
;
Ashe 2001: 363
;
Smetana 2004: 489
. Synonymized by
Blackwelder 1952: 173
.
Type
species:
Gnypeta lucens
Bernhauer 1905
.
Gnypetoma
Casey 1906: 196
;
Moore and Legner 1975: 421
;
Seevers 1978: 83
;
Ashe 2001: 363
;
Smetana 2004: 489
. Synonymized by
Blackwelder 1952: 173
.
Type
species:
Tachyusa baltifera
LeConte 1863
.
Diagnosis
Members of this genus may be distinguished by the following combination of characters: tarsi 4, 5, 5-articulated (
Figs 1
,
2
); body medium sized, length 2.3-3.6 mm, moderately to strongly glossy, integument finely punctate and pubescent, pubescence moderately long and often silky in appearance; head and pronotum distinctly narrower than elytra (
Figs 1-20
); abdomen as broad as elytra at base or moderately narrower (
Figs 1-20
), subparallel (
Figs 3-7
), or broadening apically (
Figs 9
,
18 20
), first three visible tergites with deep basal impressions bearing coarse punctures but without pronounced longitudinal ridges (
Fig. 1
); postgenal carinae incomplete or absent (
Seevers 1978
); pronotum broadest in apical third or in the middle of the disc, and converging apically and basally (
Fig. 1
), pubescence distributed postero-laterad from the midline of the disc (
Figs 1-20
); elytra much broader than both head or pronotum, and often with wavy pubescence pattern on both sides (
Figs 1-20
); mesoventral process moderately broad, attaining middle of mesocoxae, its apex truncate (
Fig. 2
); metaventral process broadly rounded (
Fig. 2
); first visible three tergites with deep basal impressions bearing coarse punctures; legs long and slender; basal article of metatarsus moderately elongate and usually shorter than the two following articles combined (
Fig. 1
). GENITAL STRUCTURES: median lobe of aedeagus consists of an enlarged, swollen bulbus and short, triangularly produced tubus (
Figs 40, 41
,
49
,
58
,
67, 68
,
76
,
84
,
92
,
100
,
109
,
110
,
118
,
131
,
132
,
140
,
141
,
149
,
157
,
165
,
173
,
182
), crista apicalis of bulbus large and subtriangular in shape laterally (
Figs 39
,
48
,
57
,
56
); paramere broad with short apical lobe bearing three long subapical and one short apical macrosetae (
Figs 60
,
77
,
85
,
119
,
142
,
150
); male tergite 8 truncate, or rarely emarginated apically, its apical
Fig. 1.
Gnypeta nigrella
(LeConte)
, in dorsal view. Scale =
1 mm
.
Fig. 2.
Gnypeta
nigrella
(LeConte)
, in ventral view. Scale = 1 mm.
margin smooth or with small 2-4 dents (
Figs 43
,
52
,
61
,
78
,
103
,
112
,
167
); spermatheca of four
types
: S-shaped (
Figs 105
,
114
,
153
,
161
), C-shaped (
Figs 122
,
127-129
,
136
), hatchet-shaped (
Figs 45
,
54
,
63
,
72
,
80
,
88
,
96
), or club-shaped (
Figs 169
,
178
,
186, 187
); capsule tubular with apical part approximately spherical (
Figs 145
,
169
,
178
,
186, 187
), tubular (
Figs 122
,
127
,
153
,
161
), or funnel-shaped (
Figs 45
,
54
,
63
,
72
); stem tubular, elongate, more or less sinuate and moderately swollen basally.
Figs 3-8.
Gnypeta
species: 3,
G. ashei
; 4,
G. brincki
; 5,
G. atrolucens
; 6,
G. sellmani
: 7,
G. dentata
; and 8,
G. groenlandica
. Scale =
1 mm
Sternite 8 of male and female with broad space between basal margin and antecostal suture (
Figs 44, 47
,
53, 56
,
62, 65
).
Gnypeta
is readily distinguished from most genera of
Oxypodini
by having 4, 5, 5-articulated tarsi and from closely related
Tachyusa
by robust body (slender in
Tachyusa
), abdomen at base as broad as elytra or only slightly narrower (much narrower in
Tachyusa
), lack of distinctive ridges in abdominal tergal impressions, and by less elongate basal article of metatarsus (usually shorter than the
Figs 9-14.
Gnypeta
species: 9,
G. brevicornis
; 10,
G. caerulea
; 11,
G. lohsei
; 12,
G. crebrepunctata
; 13,
G. manitobae
[apical part of abdomen removed]; 14,
G. uteana
. Scale =
1 mm
two following articles combined).
Ischnopoda
Stephens
is another related genus to
Gnypeta
, which differs externally by parallel-sided body, and extremely elongate metatarsus, exceeding 4/5 length of metatibia, and with basal article at least as long as the two following articles combined (
Fig. 1
). According to
Paśnik (2007)
the genus
Gnypeta
is closely related to
Tachyusa
,
Ischnopoderona
(Scheerpeltz)
and
Ischnopoda
. The key for these four genera is provided by
Paśnik (2007)
.
Figs 15-20.
Gnypeta
species: 15,
G. carbonaria
; 16,
G. helenae
; 17,
G. canadensis
; 18,
G. nigrella
; 19,
G. saccharina
; and 20,
G. minuta
[18-20, apical part of abdomen removed]. Scale =
1 mm
Figs 21-38.
Antennae of
Gnypeta
species:
G. ashei
: 21a. male, 21b. female;
G. brincki
: 22a. male, 22b. female;
G. atrolucens
: 23a. male, 23b. female;
G. sellmani
: 24a. male, 24b. female;
G. dentata
: 25a. male, 25b. female;
G. groenlandica
: 26a. male, 26b. female:
G. brevicornis
: 27a. male, 27b. female;
G. caerulea
: 28a. male, 28b. female;
G. lohsei
: 29a. male, 29b. female;
G. crebrepunctata
: 30a. male, 30b. female;
G. manitobae
: 31b. female;
G. uteana
: 32a. male, 32b. female;
G. carbonaria
: 33a. male, 33b. female;
G. helenae
: 34a. male, 34b. female;
G. canadensis
: 35a. male, 35b. female;
G. nigrella
: 36a. male, 36b. female;
G. saccharina
: 37a. male, 37b. female;
G. minuta
: 38a. male, 38b. female. Scale =
1 mm
Collection
and habitat data
Adults are associated with riparian habitats and debris along the margins of marshes, ponds, lakes, and streams (
Ashe 2001
). Some Canadian species were found in cold wet moss alongside streams. They may also occur in vegetation and litter along edges of streams, river, and lakes, in grass tussocks on mud flats, in gravel, wooded bogs, beaver lodges, and decaying fungi.
Phylogenetic
affiliations
Seevers (1978)
classified the genus
Gnypeta
in the tribe
Oxypodini
and the subtribe
Tachyusae
(=Tachyusina Thomson), together with the genera
Tachyusa
Erichson
,
Trachyota
Casey
,
Teliusa
Casey
,
Gnypetella
Casey
,
Meronera
Sharp
, and
Brachyusa
Mulsant and Rey. He
was tempted to consider
Tachyusae
as a distinct tribe on the grounds of 4, 5, 5-articulated tarsi and the genital features but he was afraid that this arrangement would obscure the relationship of
Gnypeta
to some related oxypodine genera.
Bernhauer and Scheerpeltz (1926)
did not separate genera of Tachyusina from Falagriini and grouped them together in the subtribe
Falagriae
of the tribe
Myrmedoniini Ganglbauer.
Lohse (1974)
placed
Gnypeta
together with
Falagria
Leach
,
Cordalia
Jacobs
,
Myrmecopora
Saulcy
and allied genera of the Falagriini. We agree with
Seevers (1978)
that grouping
Tachyusae
and
Falagriae
together, mainly on the grounds of 4, 5, 5-articulated tarsi and some superficial external similarities, was artificial and unwarranted. According to
Seevers (1978)
and confirmed here by us, the
Tachyusae
lack the following specialized features of the Falagriini: paramere with codylite velum separated from the paramerite velum; pronotum much narrower at base than apex and with distinct (at least one) median sulcus (sometimes two lateral sulci present); peritremes enlarged, and contiguous with or fused to elongate prosternum; procoxal cavities closed by peritremes, prosternum and inflexed hypomera. In addition the Falagriini have a basal abdominal impression bearing a median ridge, a very distinct shape of the median lobe of the aedeagus (ovoid bulbus and tubular broad tubus), small and narrowly elongate crista apicalis of bulbus, extremely long and coiled flagellum of the internal sac of the median lobe, and the spermatheca is of a different
type
with a small spherical capsule connected to a thin stem (
Figs 165, 166, 169
in
Klimaszewski and Winchester 2002
). For diagnostic features of Tachyusina, see
Seevers (1978)
. In his worldwide treatment of
Ischnopoda
Stephens,
Paśnik (2006b)
considered this genus to be closely related to
Tachyusa
and
Gnypeta
. Based on a comparative study of mouthparts and the body chaetotaxy,
Yosii and Sawada (1976)
suggested a restricted concept of
Tachyusa
-related genera and placed
Tachyusa
together with
Gnypeta
,
and
Dacrila
Mulsant and Rey
in the
Tachyusa
series of the Athetae. Their tribal affiliation of the
Tachyusa
-related genera with athetines is strongly questionable because of the differences in the genital features of the two groups e.g., lack of the “athetine bridge” in the median lobe of the aedeagus in genera of
Tachyusini
.
Lohse (1989)
excluded
Tachyusa
,
Gnypeta
, and
Dasygnypeta
Lohse
from Falagriini and transferred them together with
Brachyusa
and
Dacrila
to the separate tribe
Tachyusini
.
Paśnik (2006b)
, in his revision of the world species of
Tachyusa
, did not provide his view on the higher classification of
Tachyusa
-related genera but did not contradict the classification proposed by
Lohse (1989)
.
Paśnik (2007)
published a revision of the African genus
Ischnopoderona
(Scheerpeltz)
, with cladistic analysis of the species. He included there the outgroup taxa of the genera
Gnypeta
,
Ischnopoda
, and
Tachyusa
. On his single most parsimonious cladogram the
Ischnopoderona
branched off as a sisiter taxon of
Tachyusa
and both of them combined formed a sister taxon of
Gnypeta
. The
Ischnopoderona
was the most basal branch of this tree.We believe that more research is needed before tribal classification of this group becomes clear and stable.