Tritoxa, Loew, 1873

Sinclair, Bradley J., Macleod, Alyssa M. & Wheeler, Terry A., 2021, Revision of the Nearctic genus Tritoxa Loew (Diptera: Ulidiidae), Zootaxa 4920 (3), pp. 359-379: 361

publication ID

https://doi.org/10.11646/zootaxa.4920.3.3

publication LSID

lsid:zoobank.org:pub:20794FBC-E83E-419F-945D-4F94C6F9A47C

DOI

http://doi.org/10.5281/zenodo.4530725

persistent identifier

http://treatment.plazi.org/id/03AF8782-FFD6-FF8B-FF13-FE68468EFA3C

treatment provided by

Plazi

scientific name

Tritoxa
status

 

Key to the species of Tritoxa  

(modified from Steyskal (1967))

1 Thorax and abdomen dark brown to black ( Fig. 1 View FIGURES 1–2 ), wings with dark brown to black background ( Fig. 9 View FIGURES 6–13 ); crossvein dm-m sinuate................................................................................. T. flexa (Wiedemann)  

- Thorax and abdomen reddish-brown to brown ( Fig. 2 View FIGURES 1–2 ), wings with brown background ( Figs 6–8, 10–13 View FIGURES 6–13 ); crossvein dm-m straight to slightly sinuate or angulate..................................................................... 2

2 Crossvein dm-m straight or slightly sinuate ( Figs 6–8, 10, 13 View FIGURES 6–13 ); silvery parafrontal microtrichose stripe very narrow, only immediately adjacent to eye ( Fig. 3 View FIGURES 3–5 )........................................................................ 3

- Crossvein dm-m angulate, or slightly angulate ( Figs 11, 12 View FIGURES 6–13 ); silvery parafrontal microtrichose stripe broad, surrounding bases of orbital setae ( Figs 4, 5 View FIGURES 3–5 )............................................................................... 7

3 Discal and subapical hyaline crossbands arcuate and parallel ( Fig. 10 View FIGURES 6–13 ); subapical hyaline crossband attaining costa basad of crossvein r-m............................................................................ T. incurva Loew  

- Discal and subapical hyaline crossbands arcuate or straight ( Figs 6–8, 13 View FIGURES 6–13 ); subapical hyaline crossband essentially straight, attaining costa apicad of crossvein r-m.................................................................... 4

4 Discal hyaline crossband reaching posterior wing margin, or at least extending beyond cell dm ( Fig. 13 View FIGURES 6–13 ); small hyaline spot in costal cell distal to humeral crossvein; silvery parafrontal microtrichia stripe distinct, extending nearly half distance from eye margin to orbital setae......................................................................... Tritoxa   sp.

- Discal hyaline crossband not extending beyond cell dm ( Figs 6–8 View FIGURES 6–13 ); costal cell distal to humeral crossvein dark, without hyaline spot; silvery parafrontal microtrichia stripe narrow, extending less than one-third distance from eye margin to orbital setae.. 5

5 Discal hyaline crossband ending in or very close to posterior distal corner of cell dm, generally tapered ( Fig. 8 View FIGURES 6–13 ); inner surstylus with row of 5–8 strong prensisetae; outer surstylus arched mesally ( Fig. 17 View FIGURES 14–17 )........................ T. decipiens   sp. nov.

- Discal hyaline crossband ending distant to posterior distal corner of cell dm and usually wide posteriorly ( Figs 6, 7 View FIGURES 6–13 ); inner surstylus with prensisetae widely separated or in tight cluster; outer surstylus straight or arched ( Figs 14, 16 View FIGURES 14–17 )............ 6

6 Inner surstylus with 3–4 strong, separated prensisetae; outer surstylus straight ( Fig. 16 View FIGURES 14–17 ); phallus very long, comprising some 4–5 loops; discal hyaline crossband long, extending to opposite crossvein r-m ( Fig. 7 View FIGURES 6–13 ).................. T. cuneata Loew  

- Inner surstylus with straight row of 4–5 thick prensisetae in tight cluster, decreasing in size with largest adjacent to outer surstylus ( Fig. 14 View FIGURES 14–17 ); outer surstylus arched ( Fig. 14 View FIGURES 14–17 ); phallus much shorter than typical of genus, comprising 2 loops ( Fig. 15 View FIGURES 14–17 ); discal hyaline crossband shorter, not reaching opposite r-m crossvein ( Fig. 6 View FIGURES 6–13 ).......................... T. californica   sp. nov.

7 Crossvein dm-m with stump vein ( Fig. 12 View FIGURES 6–13 ); silvery parafrontal microtrichia stripe extending 1/4 to 1/3 distance from eye margin to midfrons ( Fig. 5 View FIGURES 3–5 ); discal hyaline crossband continuous from R 1 to posterior wing margin ( Fig. 12 View FIGURES 6–13 ); anepisternum shiny............................................................................................. T. ra Harriot

- Crossvein dm-m usually without stump vein ( Fig. 11 View FIGURES 6–13 ); silvery parafrontal microtrichia stripe extending halfway from eye margin to midfrons ( Fig. 4 View FIGURES 3–5 ); discal hyaline crossband disjunct along R 2+3 ( Fig. 11 View FIGURES 6–13 ); anepisternum densely clothed in yellow microtrichia............................................................................. T. pollinosa Cole  

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Ulidiidae