Pelodiaetus nunni, Sokolov, Igor M., 2019

Sokolov, Igor M., 2019, A review of the genus Pelodiaetus Jeannel (Coleoptera, Carabidae, Anillini) of New Zealand, with re-description of the genus, description of a new species, and notes on the evolutionary history, ZooKeys 879, pp. 33-56 : 43

Pelodiaetus nunni sp. nov. Figs 1B, D , 2B, D , 4B , 6B , 7A-D , 8

Type material.

HOLOTYPE, male, in NZAC, labeled: / New Zealand MC Ahuriri SR Port Hills 31 May 08 / Washed soil sample, broad-leaf forest / NZMS 260 M36: 797303 455m /.

PARATYPES (7 specimens, in NZAC, JTN), 4 males and 2 females labeled same as holotype; 1 female labeled: / New Zealand MC Ahuriri SR Port Hills 7 Apr 07 / Washed soil sample, broad-leaf forest /.

Specific epithet.

The specific epithet is a Latinized eponym in the genitive case, and is based on the surname of John T. Nunn, the collector of this species.

Type locality.

New Zealand, South Island, Canterbury, Port Hills Range.

Recognition.

Adults of this species ( Fig. 6B ) are practically indistinguishable from the adults of P. sulcatipennis ( Fig. 6A ) and are distinguished from the latter by the structure of male and female genitalia.

Description.

With character states of the genus as summarized above.

Size. Small to medium for genus (SBL range 1.25-1.32 mm, mean 1.30 ± 0.028 mm, n = 6).

Habitus. Body form subdepressed, subparallel, moderately elongate (WE/SBL 0.33 ± 0.012), head comparatively wide for genus (WH/WPm 0.84 ± 0.011), pronotum of moderate width in comparison to elytra (WPm/WE 0.83 ± 0.045).

Color. Body color rufo-testaceous, appendages testaceous.

Prothorax. Pronotum moderately long (LP/LE 0.41 ± 0.011) and comparatively elongate (WPm/LP 1.19 ± 0.049), with lateral margins arcuately constricted posteriorly (WPm/WPp 1.48 ± 0.059). Width between anterior angles slightly greater than between posterior angles (WPa/WPp 1.21 ± 0.080).

Elytra. Slightly depressed along suture, comparatively long (LE/SBL 0.57 ± 0.004) and moderately narrow (WE/LE 0.58 ± 0.019). Lateral margins slightly divergent at basal third, subparallel at middle and evenly rounded to apex in apical third.

Male genitalia. Median lobe ( Fig. 7A ) with almost straight ventral margin and short apex with tapering tip. Sclerites of internal sac flagelliform, long, almost equal the length between apical and basal orifices, weakly sclerotized except basal enlargement.

Female internal genitalia. Spermatheca weakly sclerotized, moderately elongate ( Fig. 7D ). Spermathecal duct long without coils. Attachments of spermathecal duct and gland to spermatheca close together.

Geographic distribution.

This species is known from the coastal Mid Canterbury area of Crosby et al. (1998), where its distribution is limited by Port Hills Range ( Fig. 8 , white circles).

Habitat.

Specimens were collected from soil in a broadleaf forest.

Relationships.

Based on the structure of male genitalia and spermatheca P. nunni is postulated to be the sister, more derived taxon of P. sulcatipennis .

Figures

Figure 1. SEM illustrations of head, dorsal aspect, and labial complex, ventral aspect, of Pelodiaetus species. A, C P. sulcatipennis B, D P. nunni. Abbreviations: cl - clypeus; cs - clypeal seta; fcc - fronto-clypeal carina; fs - frontal seta; gsc - glossal sclerite; lb - labrum; lms - lateral mental seta; lss - lateral submental setae; m - mentum; mp 3 - maxillary palpomere 3; mp 4 - maxillary palpomere 4; mt - mental tooth; mss - mental-submental suture; pms - paramedial mental seta; pos - postorbital seta; prss - primary basal submental seta; sm - submentum; ssa - anterior supraorbital seta; ssp - posterior supraorbital seta. Scale bars: 0.1 mm (A, B); 0.05 mm (C, D).

Figure 2. SEM illustrations of pronotum, dorsal aspect, and prothorax, ventral aspect, of Pelodiaetus species. A, C P. sulcatipennis B, D P. nunni. Abbreviations: bs - basilateral pronotal seta; ed 2 - scutellar seta; ls - midlateral pronotal seta; mg - marginal pronotal gutter; pep - proepipleuron; pes - proepisternum; prcx - procoxa; ps - prosternum; psp - prosternal intercoxal process; sct - scutellum. Scale bars 0.1 mm.

Figure 4. SEM illustrations of chaetotaxy of elytra, dorso-lateral aspect, of Pelodiaetus species. A P. sulcatipennis B P. nunni. Abbreviations: ed 2 - scutellar seta; ed 3 - 1 st discal seta; ed 5 - 2 nd discal seta; ed 6 - 3 d discal seta; ed 8 - apical seta; eo 1 - 9 - setae 1 - 9 from the umbilical series. Scale bars 0.2 mm.

Figure 6. Digital images of habitus of Pelodiaetus species, dorsal aspect. A P. sulcatipennis (NZ, Otago, Outram) B P. nunni (NZ, Canterbury, Ahuriri Scenic Reserve). Scale bar: 1.0 mm.

Figure 7. Line drawings of male genitalia and female spermathecae of Pelodiaetus species. P. nunni (NZ, Canterbury, Ahuriri Scenic Preserve): A median lobe, right lateral aspect B left paramere, left lateral aspect C right paramere, right lateral aspect D spermatheca. P. sulcatipennis (NZ, Otago, Outram): E median lobe, right lateral aspect F left paramere, left lateral aspect G right paramere, right lateral aspect H spermatheca. Abbreviations: ds - dorsal sclerites; sd - spermathecal duct; sg - spermathecal gland; sp - spermatheca. Scale bars: 0.1 mm (A, B, C, E, F, G); 0.05 mm (D, H).

Figure 8. Map of southern half of South Island, New Zealand, showing positions of locality records for the species of Pelodiaetus: P. nunni, white circles; P. sulcatipennis, yellow circles. Elevation scale bars are given in meters.