Oecetis, McLachlan, 1877

Johanson, Kjell Arne, Mary, Nathalie Jeanne, Sjöberg, Tin & Malm, Tobias, 2020, Eighteen new species of Oecetis McLachlan 1877 (Trichoptera, Leptoceridae) from New Caledonia, Zootaxa 4809 (2), pp. 201-240 : 233-234

publication ID	https://doi.org/ 10.11646/zootaxa.4809.2.1
publication LSID	lsid:zoobank.org:pub:E697983F-7223-4009-91B4-80A401D0AB8A
DOI	https://doi.org/10.5281/zenodo.4333673
persistent identifier	https://treatment.plazi.org/id/03C0C513-FFE4-FFD3-D997-003590DC34FE
treatment provided by	Plazi
scientific name	Oecetis
status

Treatment

Key to New Caledonian Oecetis View in CoL species, males

1 Tergum X divided into bilobed main branch and posterior spine ( Figs 1 View FIGURES 1–5 , 21 View FIGURES 21–25 , 57 View FIGURES 57–61 ); upper posterolateral process on each side of segment IX not exceeding tergum X posteriorly............................................................. 2

- Tergum X lacking posterior spine ( Figs. 73-74 View FIGURES 73–77 ); upper posterolateral process of segment IX exceeding tergum X posteriorly ( Fig. 73 View FIGURES 73–77 ) ……....................................................................... Oecetis flucta sp. nov.

2 Tergum X with posterior spine longer than main branch ( Figs 21 View FIGURES 21–25 , 41 View FIGURES 41–45 , 46 View FIGURES 46–50 )......................................... 3

- Tergum X with posterior spine as long as ( Figs 6 View FIGURES 6–10 , 16 View FIGURES 16–20 , 31 View FIGURES 31–35 , 88 View FIGURES 88–92 ) or shorter than ( Figs 1 View FIGURES 1–5 , 11 View FIGURES 11–15 , 26 View FIGURES 26–30 , 36 View FIGURES 36–40 , 83 View FIGURES 83–87 ) main branch........ 10

3 Tergum X with posterior spine curved strongly ventrad (Figs 51, 57, 62).......................................... 4

- Tergum X with posterior spine almost straight ( Fig. 21 View FIGURES 21–25 ) or curved slightly ventrad ( Figs 41 View FIGURES 41–45 , 46 View FIGURES 46–50 , 67 View FIGURES 67–72 , 78 View FIGURES 78–82 )................. 6

4 Superior appendages as long as main branch of tergum X ( Fig. 57 View FIGURES 57–61 ); posterior spine very long and more slender than coxopodites in lateral view ( Fig. 57 View FIGURES 57–61 ).............................................................. Oecetis gracilis sp. nov.

- Superior appendages about half as long as main branch of tergum X (Figs 51, 62); posterior spine about as thick as or thicker than coxopodites in lateral view (Figs 51, 62)............................................................... 5

5 Coxopodites curving slightly ventrad in lateral view ( Fig. 62 View FIGURES 62–66 ); posterior spine uniformly curving along its length in lateral view ( Fig. 62 View FIGURES 62–66 )........................................................................ ….. Oecetis rostra sp. nov.

- Coxopodites curving slightly dorsad in lateral view (Fig. 51); posterior spine curving strongly ventrad after mid-length in lateral view (Fig. 51)................................................................. Oecetis multidentata sp. nov.

6 Coxopodites exceeding posterior spine of tergum X posteriorly in lateral view ( Fig. 21 View FIGURES 21–25 )............ Oecetis millei sp. nov.

- Coxopodites not exceeding posterior spine of tergum X posteriorly in lateral view ( Figs 41 View FIGURES 41–45 , 46 View FIGURES 46–50 , 67 View FIGURES 67–72 , 78 View FIGURES 78–82 )................. 7

7 Main branch of tergum X thicker than posterior spine in lateral view ( Fig. 46 View FIGURES 46–50 ); coxopodites each with long branch directed dorsad ( Fig. 46 View FIGURES 46–50 ).............................................................. ….. Oecetis dorsospina sp. nov.

- Main branch of tergum X more slender than posterior spine in lateral view ( Figs 41 View FIGURES 41–45 , 67 View FIGURES 67–72 , 78 View FIGURES 78–82 ); coxopodites directed posterad ( Fig. 41 View FIGURES 41–45 , 67 View FIGURES 67–72 , 78 View FIGURES 78–82 )........................................................................................... 8

8 Coxopodites curving ventrad along their length ( Fig. 78 View FIGURES 78–82 )........................ Oecetis nouvellecaledonensis sp. nov.

- Coxopodites not curving ventrad along their length ( Figs 41 View FIGURES 41–45 , 67 View FIGURES 67–72 )................................................ 9

9 Coxopodites each divided into three branches ( Fig. 67 View FIGURES 67–72 ); superior appendages almost as broad as long in dorsal view ( Fig. 68 View FIGURES 67–72 ); phallus with three sclerotized processes or spines ( Fig. 71 View FIGURES 67–72 ) ….............................. Oecetis triramosa sp. nov.

- Coxopodites simple, undivided ( Fig. 41 View FIGURES 41–45 ); superior appendages clearly longer than broad in dorsal view ( Fig. 42 View FIGURES 41–45 ); phallus with one sclerotized process or spine ( Fig. 44 View FIGURES 41–45 ).................................... …………...... Oecetis oxybelis sp. nov.

10 Tergum X with posterior spine as long as main branch ( Figs 6 View FIGURES 6–10 , 16 View FIGURES 16–20 , 31 View FIGURES 31–35 , 88 View FIGURES 88–92 )....................................... 11

- Tergum X with posterior spine shorter than main branch ( Figs 1 View FIGURES 1–5 , 11 View FIGURES 11–15 , 26 View FIGURES 26–30 , 36 View FIGURES 36–40 , 83 View FIGURES 83–87 )................................... 14

11 Coxopodites each with long, posteriorly curving, spine-like dorsal process ( Fig. 88 View FIGURES 88–92 )............... Oecetis ovata sp. nov.

- Coxopodites without long dorsal processes ( Figs 6 View FIGURES 6–10 , 16 View FIGURES 16–20 , 31 View FIGURES 31–35 )................................................... 12

12 Coxopodites in lateral view each with rectangular basal half separated from slender distal half ( Fig. 31 View FIGURES 31–35 ).................................................................................................. Oecetis rostrata sp. nov.

- Coxopodites in lateral view each with basal half not rectangular ( Figs 6 View FIGURES 6–10 , 16 View FIGURES 16–20 )..................................... 13

13 Coxopodites in ventral view with wide and long mesal plates only at base ( Fig. 18 View FIGURES 16–20 ); in lateral view with narrow triangular upper posterolateral process of segment IX ( Fig. 16 View FIGURES 16–20 )......................................... Oecetis loyolaensi sp. nov.

- Coxopodites in ventral view with wide and short mesal plates at mid-length ( Fig. 8 View FIGURES 6–10 ); in lateral view with wide triangular upper posterolateral process of segment IX ( Fig. 6 View FIGURES 6–10 ).............................................. Oecetis ovula sp. nov.

14. Superior appendages long, exceeding rest of genitalia posteriorly and each with bifurcated apex in lateral view ( Fig. 11 View FIGURES 11–15 )..................................................................................... Oecetis ramosa sp. nov.

- Superior appendages shorter than tergum X and each with rounded apex in lateral view ( Figs 1 View FIGURES 1–5 , 26 View FIGURES 26–30 , 36 View FIGURES 36–40 , 83 View FIGURES 83–87 )............. 15

15. Coxopodites each with ventral branch at base ( Figs 83, 85 View FIGURES 83–87 )................................ Oecetis variabilis sp. nov.

- Coxopodites without ventral branches at base ( Figs 1 View FIGURES 1–5 , 26 View FIGURES 26–30 , 36 View FIGURES 36–40 )................................................. 16

16. Coxopodites in lateral view each with basal third more than 4 times taller than distal third ( Fig. 1 View FIGURES 1–5 ); main branch of tergum X curving slightly ventrad in lateral view ( Fig. 1 View FIGURES 1–5 ); phallus more than seven times longer than narrowest part in lateral view ( Fig. 4 View FIGURES 1–5 ).............................................................................. Oecetis amphora sp. nov.

- Coxopodites in lateral view each with basal third less than 4 times taller than distal third ( Figs 21 View FIGURES 21–25 , 36 View FIGURES 36–40 ); main branch of tergum X straight in lateral view ( Figs 26 View FIGURES 26–30 , 36 View FIGURES 36–40 ); phallus less than four times longer than narrowest part in lateral view ( Figs 29 View FIGURES 26–30 , 39 View FIGURES 36–40 ) 17

17. Segment IX anterior margins in lateral view slightly convex ( Fig. 26 View FIGURES 26–30 ); acrotergite IX forming uniform punctate area ( Fig. 27 View FIGURES 26–30 ); superior appendages about 3 times longer than tall in lateral view ( Fig. 26 View FIGURES 26–30 ); distal part of each coxopodite angled slightly posterad in lateral view ( Fig. 26 View FIGURES 26–30 )....................................................... Oecetis christinae sp. nov.

- Segment IX anterior margin in lateral view strongly convex ( Fig. 36 View FIGURES 36–40 ); acrotergite IX forming two separate punctate areas ( Fig. 37 View FIGURES 36–40 ); superior appendages about 1.5 times longer than tall in lateral view ( Fig. 36 View FIGURES 36–40 ); distal part of coxopodites curving slightly dorsad in lateral view ( Fig. 36 View FIGURES 36–40 ).......................................................... Oecetis alicae sp. nov.