Paulianidia, Koszela & Sarmiento & Żyła, 2023

Koszela, Katarzyna, Sarmiento, Yoan Camilo Guzman & Żyła, Dagmara, 2023, A new species of the genus Paulianidia Jarrige and a new combination in Pseudolathra Casey (Coleoptera, Staphylinidae, Paederinae), Zootaxa 5343 (6), pp. 521-530 : 528-529

Key to species of Paulianidia

The newly described species is incorporated into the key of Lecoq (2008). The key has been translated and slightly modified in order to adapt it to widely accepted Paederinae morphological terminology ( Bogri et al. 2020).

1. Integument of posterior half of head and pronotum distinctly reticulated between punctures................. P. reticulata

- Integument of head and pronotum smooth between punctures (weakly reticulate in P. marojejy )....................... 2

2. Elytra shorter and equal to or narrower than pronotum.............................................. P. microptera

- Elytra at least as long as and wider than pronotum........................................................... 3

3. Elytral punctures raised, coarse or granular................................................................. 4

- Elytral punctures depressed, not coarse or granular........................................................... 6

4. Temples receding, straight for most of their length; eyes much shorter than temples (R = 0.55)................ P. marojejy

- Temples evenly rounded to neck; eyes almost as long as temples................................................ 5

5. Size: 5.2 mm; antennomeres 8–10 transverse; head as wide as pronotum............................... P. densipennis

- Size: 6.4 mm; antennomers 8–10 at most square; head slightly wider than pronotum........................... P. nigra

6. Pronotum with straight lateral margins, subparallel over large part of their length................................... 7

- Pronotum with regularly convex lateral margins, narrowed anteriorly............................................ 8

7. Antennomeres 8–10 subquadrate or elongate; metatrochanter elongate and pointed.......................... P. armata

- Antennomers 8–10 distinctly transverse; metatrochanter not elongate, regular....................... P. descarpentriesi

8. Head punctation sparser in centre of disc, leaving only small sparsely punctate area................................ 9

- Head punctation dense, progressively less dense from front to back but not leaving small sparsely punctate area in centre of disc............................................................................................... 12

9. Integument of tergites smooth between punctures.......................................................... 10

- Integument of tergites with fine and shallow microstriae..................................................... 11

10. Punctation of tergites very fine and dense; body length: 5 mm ........................................... P. hova

- Punctation of tergites fine and sparse; body length: 4 mm ............................................. P. minima

11. Elytra more than half longer than pronotum (R = 1.55); elytral punctures dense; male: parameres hooked in apical portion.............................................................................................. P. itremo

- Elytra slightly longer than pronotum (R = 1.15); elytral puncture sparse; male: parameres wide from base to apex, apical portion pointed...................................................................................... P. janaki

12. Integument of abdominal tergites without microsculpture between punctures..................................... 13

- Integument of abdominal tergites with wrinkled, striate or reticulate microsculpture............................... 17

13. Curvature of temples not very pronounced, making them more or less receding.......................... P. peyrierasi

- Curvature of temples more pronounced................................................................... 14

14. Size: 5.4 mm; temples evenly curved; elytra slightly longer than wide (R = 1.14)............................ P. vicina

- Size: 4.6–4.8 mm; temples subrectilinear, starting from eyes for half their length; elytra slightly more rectangular (R = 1.18– 1.20).............................................................................................. 15

15. Pronotal punctation coarser; elytral punctation coarse and more widely spaced........................... P. hammondi

- Pronotal punctation finer; elytral punctation less coarse...................................................... 16

16. Aedeagus: parameres no longer than median lobe............................................... P. andringitrensis Aedeagus: parameres longer than median lobe.......................................... P. parahammondi sp. nov.

17. Small subapterous species not exceeding 4.5 mm in length; antennomere 3 about 1/5 longer than preceding; elytra as long as pronotum.................................................................................. P. parvalata

- Larger species, at least 5 mm long...................................................................... 18

18. Tergite VIII lacking striae or reticulation; other tergites with fine, inconspicuous superficial reticulation.......... P. ikoka

- Tergite VIII visibly reticulated, like preceding segments..................................................... 19

19. Elytra with fine, dense, rasp-like punctation........................................................ P. pauliani

- Elytra with sparser and coarser punctation................................................................ 20

20. Head longer than wide (R = 1.10)................................................................. P. fisheri

- Head as long as wide................................................................................. 21

21. Eyes larger in relation to temples (R = 0.70)........................................................ P. steineri

- Eyes smaller in relation to temples (R = 0.55–0.60)......................................................... 22

22. Aedeagus: apex of median lobe simple, poorly developed.................................................... 23

- Aedeagus: apex of median lobe widened................................................................. 24

23. Aedeagus: parameres slender, narrow............................................................. P. elegans

- Aedeagus: parameres wider and thicker........................................................ P. ivohibensis

24. Elytra considerably longer than pronotum (R = 1.40)................................................. P. proxima

- Elytra slightly longer than pronotum (R = 1.15)..................................................... P. brunnea

Comments. The placement of Paulianidia within the subtribe Lathrobiina lacks confirmed phylogenetic validation and seems artificial. According to Żyła et al. (2021), the most important synapomorphic character for the diagnosis of this lineage is the expanded area of the protibia that holds the comb-like rows of setae (protibial combs). Paulianidia lacks such an area, which led us to a preliminary conclusion that the genus does not, in fact, belong to the subtribe Lathrobiina . However, due to the lack of phylogenetic estimation here, we do not decide to exclude it from the subtribe yet. Our ongoing large-scale phylogenetic studies will allow for a formal decision soon (Żyła et al., in prep.). Based on morphological similarities, like the shape of head and pronotum, similar shape of labrum and maxillary palpomeres, it seems plausible that the Oriental genus Enallagium , which has been previously suggested as similar, is a close relative of Paulianidia .

Among Madagascan Paederinae , Paulianidia is easily distinguished by the acicular maxillary palpomere 4 (from Pinophilini , Paederini and Lathrobiini : Micrillus ), the transversally placed protibial combs (from Medonina , Astenina , Stilicopsina , and Stilicina), and by the wide neck, not narrower than 1/3 of head width (from Scopaeina ). A single, unique diagnostic character, which is easy to observe, is the presence of two longitudinal shallow depressions laterally in the posterior half of the pronotum.