Tasmanitachoides erwini, Maddison & Porch, 2021

Maddison, David R. & Porch, Nick, 2021, A preliminary phylogeny and review of the genus Tasmanitachoides, with descriptions of two new species (Coleoptera, Carabidae, Bembidarenini), ZooKeys 1044, pp. 153-196 : 153

Tasmanitachoides erwini sp. nov. Figures 1 , 2C , 12C , 16B , 17G , 18B , 19C , 20B, C , 21

Material examined.

Holotype. Male (ANIC), labeled: " Australia: Tasmania: River Forth at C136, 41.4712°S 146.1366°E, 126 m, 14.i.2019. DRM 19.012. D.R. Maddison & N.A. Porch ", " David R. Maddison DNA5509 DNA Voucher" [pale green paper], " HOLOTYPE Tasmanitachoides erwini Maddison & Porch" [partly handwritten, on red paper]. Genitalia mounted in Euparal on coverslip pinned with specimen; extracted DNA stored separately. GenBank accession numbers for DNA sequences of the holotype are MW291170, MW291262, MW291215, MW291234 , and MW291305 .

Paratypes (23). Same label data as holotype (20; ANIC, OSAC, NPC, ZSM, NMV, QVMAG, NHMUK, TMAG, USNM). In addition to these, we have seen three additional specimens, all in the MCZ, which we have designated as paratypes. Two are a labeled " L. StClaire-Queenstown Jan. '57 Tas Darlingtons" " Tachys Tasmanitachoides hobarti (Sl.) det Darl. ‘61”; according to Darlington (1962:117) these two specimens are from the crossing of the King River by the Queenstown road, which at the time (before the Crotty Dam) would have been approximately 42.074°S 145.652°E. The third is labeled " Mersey R Vy. Mar. '57 Tas Darlingtons" " Tachys Tasmanitachoides hobarti (Sl.) det Darl. ‘61”. According to the map in Darlington (1960), this locality is at approximately 41.532°S, 146.426°E. These specimens formed Darlington’s concept of Tasmanitachoides hobarti . They also are specimens studied and figured by Erwin (1972) as T. hobarti .

Type locality.

Australia: Tasmania: at the mouth of Machinery Creek into the River Forth at road C136, 41.4712°S, 146.1366°E, 126 m.

Derivation of specific epithet.

We are honored to name this species after the late Terry Lee Erwin, for his many contributions to carabidology and systematics in general, and to our knowledge of Tasmanitachoides and other bembidarenines in particular.

Diagnosis and description.

Length 2.25-2.75 mm (n = 7); most specimens less than 2.6 mm. One of the darker species of Tasmanitachoides (Fig. 1 ): body piceous to black; appendages piceous, including basal antennomeres, with the exception of the tarsi, which are slightly paler. Body relatively flat and parallel-sided; elytra narrowing posteriorly, and thus more pointed than other species. Head without tubercles at anterior corners of clypeus, and without concave region in anterior half. Frontal furrows (Fig. 17G ) more or less straight, reaching backward to approximately the center of the eye, parallel or slightly diverging posteriorly; bottom of furrows rugose. Pronotum relatively narrow (Fig. 12C ), slightly sinuate laterally in front of the right or slightly acute hind angle. First stria abruptly sinuate, very close to the suture in the anterior fifth or fourth, at which point it abruptly bends away from the suture. Striae 3 and 4 very weak, almost absent in some specimens; the striae 3 and 4 are joined at the anterior discal seta (ed3; Fig. 16B ), and in most specimens are merged in front of that point. Stria 5 distinctly engraved throughout the entire anterior half; in posterior half it gradually weakens toward the rear. Stria 6 consisting of a few isolated punctures; stria 7 absent. Discal setae ed6 in stria 3. Microsculpture weak, sculpticells weakly engraved, and thus the surface is shiny; sculpticells isodiametric on head and pronotum, slightly longitudinally stretched on elytra (Fig. 18B ). Aedeagus (Figs 19C , 20B, C ) with internal sac sclerites elongated and relatively straight, very similar to those of T. sp. "Lerderderg R" (Fig. 19D ). Ventral surface of the aedeagus quite straight (Fig. 20B, C ).

Comparison with related species.

As with other members of the Tasmanitachoides wattsensis group, this species has a relatively unmodified clypeus, without anterior lateral tubercles, and with the third and fourth elytral striae nearly effaced. Its darker color (including the entirely piceous antenna) and flatness distinguish it from other members of the group. It is the only known species of the group from Tasmania. From the other two large and dark Tasmanitachoides from Tasmania, T. hobarti and T. leai , T. erwini is distinguished by having a darker antennomere 1 and flatter body. From T. hobarti it is further distinguished by the much weaker striae 3 and 4; from T. leai by the longer stria 5.

Geographic distribution.

Only known from northwestern Tasmania (Fig. 21 ).

Habitat.

At the type locality, members of this species were found during daylight hours in fine gravel on the banks of Mineral Creek at its mouth into the River Forth (Fig. 2C ); specimens were found after splashing the gravel with water. The banks had no visible vegetation. Present in the same habitat were Tasmanitachoides leai , T. kingi , and T. sp. "River Forth".

Phylogenetic relationships.

This species belongs to the Tasmanitachoides wattsensis species group, and appears to be the sister to T. sp. "Lerderderg R" among the sampled species (Figs 5 - 9 ).

Notes.

This is the species illustrated by Erwin (1972) as T. hobarti . This is evident both by the localities of the specimens he examined (as the localities match Darlington’s), and because of the figures themselves, including the features of the genitalia, which match those of this species rather than T. hobarti . The male genitalia of " Tasmanitachoides hobarti " figured in Baehr (1990: Fig. 12 ) is of this species as well. Some specimens from the type series (collected 14 January 2019) are teneral.

Figures

Figure 1. Tasmanitachoides erwini sp. nov., adult male, from the type locality. Scale bar: 1 mm.

Figure 2. Habitats of Tasmanitachoides A Australia: ACT: Murrumbidgee River at Angle Crossing, 35.5825 ° S, 149.1100 ° E, 598 m. This and similar areas a few meters upstream are habitat of T. murrumbidgensis, T. sp. " Tambo R ", T. cf. gerdi, T. sp. " Angle Crossing 1 ", T. wilsoni, T. maior, T. sp. " Angle Crossing 2 ", and T. rufescens B Australia: Victoria: Flat Rock Creek at highway B 23, 37.2835 ° S, 149.2223 ° E, 256 m. Habitat of T. lutus, T. leai, and T. angulicollis C Australia: Tasmania: mouth of Machinery Creek into the River Forth at C 136, 41.4712 ° S, 146.1366 ° E, 126 m. Habitat of T. leai, T. kingi, T. erwini, and T. sp. " River Forth " D Australia: Tasmania: Lake St Clair, 42.1121 ° S, 146.2051 ° E, 741 m. Habitat of T. hobarti.

Figure 5. Maximum likelihood tree for the concatenated matrix of all gene fragments (main figure) and for the concatenated matrix of all genes except COI (inset; this shows only part of the tree). Branch length is shown proportional to relative divergence, as estimated by IQ-TREE; scale bar indicates 0.01 units. Outgroups (Bembidarenas, Argentinatochoides, and Andinodontis; Table 1) not depicted.

Figure 9. Maximum likelihood trees for wg, CAD 4, and CAD 2. Branch length is shown proportional to relative divergence, as estimated by IQ-TREE; scale bars indicate 0.01 units. Outgroups not depicted.

Figure 12. Adults of the Tasmanitachoides wattsensis group and other Tasmanitachoides A T. wattsensis, voucher DNA 5758; NSW: Leatherbarrel Creek u / s Alpine Way B T. sp. " Lerderderg R ", voucher V 101049; VIC: Lerderderg River, 6.8 km N. Bacchus Marsh C T. erwini, voucher V 101469 D T. leai, voucher V 101467 E T. hobarti, voucher V 101463 F T. glabellus, paratype. Scale bars: 1.0 mm.

Figure 16. Left elytron of Tasmanitachoides A T. sp. " Lerderderg R ", voucher V 101049 B T. erwini, voucher V 101469 C T. hobarti, voucher V 101463 D T. leai, voucher V 101467 E T. rufescens, voucher V 101478 F T. sp. " River Forth ", voucher DNA 5555 G T. sp. " Angle Crossing 2 ", voucher DNA 5678 H T. flindersianus, paratype J T. bicolor, voucher V 101472 K T. fitzroyi, voucher V 101471 L T. maior, voucher DNA 5508 M T. arnhemensis, voucher V 101476. N T. murrumbidgensis, voucher V 101464 P T. minor, voucher V 101474 Q T. sp. " Tambo R ", voucher V 101465.

Figure 17. Dorsal view of head of Tasmanitachoides adults A T. wilsoni, voucher V 101470 B T. baehri, voucher V 101479 C T. lutus, voucher V 101462 D T. cf. gerdi, voucher DNA 5676 E T. sp. " Angle Crossing 1 ", voucher DNA 5677 F T. obliquiceps, voucher V 101477 G T. erwini, voucher V 101469 H T. hobarti, voucher V 101463 J T. leai, voucher V 101467 K T. rufescens, voucher V 101478 L T. fitzroyi, voucher V 101471 M T. murrumbidgensis, voucher V 101464.

Figure 18. Elytral microsculpture of Tasmanitachoides, dorsal view A T. baehri, voucher V 101484 B T. erwini, voucher V 101483. Scale bar: 100 µm.

Figure 19. Aedeagus of Tasmanitachoides, ventral view A T. baehri, voucher DNA 5569 (holotype) B T. wilsoni, voucher DNA 5514 C T. erwini, voucher V 101481 D T. sp. " Lerderderg R ", voucher DNA 2029. Scale bars: 100 µm.

Figure 20. Aedeagus of Tasmanitachoides, left lateral view A T. baehri, voucher DNA 2032 B T. erwini, voucher DNA 5583 C T. erwini, voucher DNA 5509 (holotype). Scale bar: 100 µm.

Figure 21. Known geographic distributions of Tasmanitachoides baehri and T. erwini in southeastern Australia. Circles: T. baehri; stars: T. erwini.