Hawaiian Paratachys Casey (Coleoptera, Carabidae): small beetles of sodden summits, stony streams, and stygian voids
Author
Liebherr, James K.
https://orcid.org/0000-0001-9831-884X
Department of Entomology, John H. and Anna B. Comstock Hall, 129 Garden Ave., Cornell University, Ithaca, NY 14853 - 2601, USA
jkl5@cornell.edu
text
ZooKeys
2021
2021-06-16
1044
229
268
http://dx.doi.org/10.3897/zookeys.1044.59674
journal article
http://dx.doi.org/10.3897/zookeys.1044.59674
1313-2970-1044-229
7EC23192F85D4D2AA31E2694A59CB014
0B5B533D7CBA50819E2AEC264FE6D977
Paratachys Casey, 1918
Paratachys
Casey, 1918: 174 (type species
Paratachys austinicus
Casey by original designation);
Erwin 1974b
: 128;
Boyd and Erwin 2016
: 95, 110.
Eotachys
Jeannel, 1941: 426 (type species
Tachys bistriatus
Duftschmid by original designation). Synonymy by
Erwin (1971
: 236).
Macrotachys
Kult, 1961: 2 [junior homonym of
Macrotachys
Ueno
, 1953: 42] (type species
Bembidium fulvicolle
Dejean by original designation). Synonymy under
Eotachys
by
Lindroth (1966
: 431).
Diagnosis.
These beetles can be diagnosed by: deep paramedial pits of the mentum (Figs
1B
,
8B
,
9B
); head with two supraorbital setae each side (Figs
1C, D
,
8C, D
,
9D, F
); pronotum moderately cordate to nearly quadrate, MPW/BPW = 1.17-1.34; anterior terminus of elytral apical recurrent groove (ARG) slightly to distinctly hooked and situated laterad position of interneur 4, ARG laterally encompassing the fourth discal seta Ed5-6 (Figs
1A
,
6
,
8A
,
9A
); elytral setation including ombilicate setae in an anterior series Eo1-4, a posterior series Eo5-8 associated with posterior sulcus, and Eo9 just mesad ARG, plus dorsal setae Ed1, Ed5-6, Ed7, and Ed8; interneur 8 with posterior sulcus in apical half of elytron, the anterior portion of sulcus directed away from the elytral lateral margin and encompassing setae Eo5-6, and setae Eo7 and Eo8 situated toward the elytral apex between i8 and the apical recurrent groove; and protibia expanded laterally at apical 1/4 of length (Fig.
1A
), the associated latero-apical notch lined basally with a transverse row of closely spaced setae (e.g.,
Maddison et al. 2019
: fig. 7A).
Figure 1.
Paratachys terryli
A-I
Kauai: Namolokama Mtn.
A, B
macrophthalmic, brachypterous female; 23-v-2005 lot 01
A
dorsal habitus view
B
mentum and associated mouthparts, ventral view
C-I
compound eye, lateral view
C
macropterous female; 23-v-2005 lot 1
D
brachypterous male; 21-v-2005 lot 8
E
brachypterous male; 23-v-2005 lot 1
F
brachypterous female; 23-v-2005 lot 1
G
brachypterous female; 23-v-2005 lot 1
H
brachypterous female; 23-v-2005 lot 1
I
brachypterous female; 21-v-2005 lot 1
J
Kauai: Upper Kawaikoi Stream at Alakai Swamp Trail, 16-v-1971; right metathoracic flight wing of male, vestigial morph (elytron removed); 14-v-1991 stop 91-26B.
For Hawaiian taxa the position of the dorsal seta within the arcuate ARG differs from that in Neotropical
Paratachys
(
Boyd and Erwin 2016
) by being situated near the middle of the arc (Figs
1A
,
8A
,
9A
), not further forward near the apical hooked terminus of the groove (e.g.,
Boyd and Erwin 2016
: fig. 1A, C). This suggests that the seta within the arc may represent Ed6 in Hawaiian
Paratachys
, vs. Ed5 in Neotropical taxa (
Boyd and Erwin 2016
: fig. 1A). An anterior placement of the seta mesad the hooked terminus of the ARG is also observed in Asian
Paratachys
(
Andrewes 1925
: plate 3;
Tanaka 1956
: fig. 1;
Tanaka 1960
: fig. 1;
Habu 1977
: fig. 1;
Baehr 2017
: figs 29-34), the Palaearctic
P. bistriatus
(Duftschmid) (
Jeannel 1941
: fig. 168A) as well as numerous other Palaearctic species (
Coulon 2004
: figs 2-4), various Madagascan species (
Jeannel 1946
: fig. 154), Canary Island species (
Machado 1992
: fig. 73C, D), and Nearctic taxa such as
P. proximus
(Say) and
P. scitulus
(LeConte) (
Lindroth 1966
: figs 209f, 222).
Finally, all Hawaiian species have the cuticular surfaces of head, prothorax, elytra, meso- and metathoracic sternites, abdominal ventrites, and femora covered with a pelage of fine microsetae (Figs
1C-I
,
8C, D
,
9C-F
). These microsetae occur in line with the elytral interneurs, and on the compound eyes are set along the ommatidial margins (Figs
1B
,
8B
,
9B
). Again, this configuration differs from that of Nearctic taxa such as
P. austinicus
Casey,
P. proximus
, and
P. scitulus
(CUIC), in which only the meso- and metathoracic femora bear such a pelage and all other body surfaces are glabrous excepting macrosetae. It should be noted that some
Tachys
spp. also have the ventral surface of the meso- and metathoracic femora covered with a sparse pelage; e.g.,
T. litoralis
Casey,
T. mordax
LeConte, and
T. vittiger
LeConte.
Setitachys macrops
Baehr (2016)
of northern Australia also bears a setose pelage over the body, but this species differs dramatically from the Hawaiian
Paratachys
in mandibular length, pronotal shape, elytral striation, and aedeagal configuration, suggesting an independent origin for the pelage in the two lineages. Species of the
Lymnastis
Motschulsky-
Micratopus
Casey lineage (
Maddison et al. 2019
) are also characterized by such a full-body pelage (
Baehr 2016
).
Identification and generic placement.
Boyd and
Erwin's
(2016)
key to New World
Tachyina
supports generic assignment of Hawaiian
Paratachys
through use of the characters that diagnose the genus worldwide.
Andrewes'
(1925)
key to Oriental
Tachys
Dejean sensu lato is based on a similar though simplified set of characters that assigns Hawaiian
Paratachys
species to his "
triangularis
" group. Finally,
Britton (1948)
could be used firstly to generically determine Hawaiian
Paratachys
as
Tachys
, and then as the only previously described species,
Paratachys arcanicola
(Blackburn) (
Britton 1948
: 238), although
Britton's
keys do not utilize diagnostic characters (
Boyd and Erwin 2016
) that underlie taxonomic definition of
Paratachys
.
Coulon (2004)
distinguished European species of
Eotachys
Jeannel from those of
Paratachys
based on the complete eighth elytral interneur of the Nearctic
P. austinicus
Casey, type species of
Paratachys
, vs. an interrupted eighth interneur in the European
Tachys bistriatus
Duftschmid, type species of
Eotachys
. However, as the European
Tachys bistriatus
is nested within a clade of New World
Paratachys
spp., with the Hawaiian
Paratachys terryli
(reported as
Paratachys
sp. "U.S.A.: Hawaii") placed as their respective adelphotaxon in a comprehensive molecular phylogenetic analysis (
Maddison et al. 2019
, fig. 12), the synonymy of
Eotachys
under
Paratachys
reported first by
Erwin (1971)
is corroborated, and herein accepted.