Tritoxa californica, Sinclair & Macleod & Wheeler, 2021

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: 361-362

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Tritoxa californica

sp. nov.

Tritoxa californica   sp. nov.

( Figs 6 View FIGURES 6–13 , 14, 15 View FIGURES 14–17 , 24 View FIGURES 24–26 )

Type material. HOLOTYPE ♂, labelled: “ CALIF: Plumas Co. / Little Long Valley / Creek [39°52′06″N 120°42′08″W], 6000′ 6 mi. E./ Spring Garden/ VIII-4-10-1977 ”; “ Malaise Trap / 8A-6P/ M. Wasbauer / Collector”; “ HOLOTYPE / Tritoxa   / californica Sinclair   ,/ MacLeod & Wheeler” ( CSCA) GoogleMaps   . PARATYPES: USA. California: El Dorado Co., Pollack Pines [38°45′41″N 120°35′12″W], 2.ix.1986, Jackson trap, peach, D. Bolster (1♂, CSCA) GoogleMaps   ; Nipa Co., Angwin , 38.575°N 122.453°W, 17.ix.2008, McPhail trap, T. Samansky (1♂, 1♀, CSCA) GoogleMaps   ; Same data as holotype (1♂, 2♀, CSCA) GoogleMaps   ; Santa Cruz Co., Big Basin SP [37°10′21″N 122°13′21″W], 13.ix.1966, E.L. Sleeper (1♂, CAS) GoogleMaps   ; Trinity Co. [40.66°N 123.12°W], (1♂, CAS) GoogleMaps   ; Tuolumne Co., 2.7 mi E Smoky Jack [37°49′3.72″N 119°42′45.61″W], Summer 1962, Frick trap on Prunus emarginata, D.P. Allen   (1♂, CSCA) GoogleMaps   .

Possible additional material. USA. California: El Dorado Co., Placerville [38°43′47″N 120°47′55″W] GoogleMaps   ,, P.H. Arnaud (1♂, USNM) [genitalia lost]; Sagehen Ck Field Stn., 15 km N Truckee , 39°25.89′N 120°14.61′W GoogleMaps   , 16.viii.1999, J. Savage (1♀, LEM); Nevada Co., Sagehen Ck [39°25′57″N 120°14′13″W] GoogleMaps   , 2.vii.1968, R. W. Pinger (1♀, USNM)   .

Diagnosis. This species has the general appearance of Tritoxa cuneata   , but is distinguished by the short, oblique discal hyaline crossband not extending beyond level of crossvein r-m in cell dm, inner surstylus with tight cluster of 4–5 thick prensisetae and phallus is shorter, with two loops.

Description. Entirely yellowish brown to brown, abdomen darker brown bands. Head: ocellar triangle dark brown to black, microtrichose; frons yellowish brown to brown; parafrontal silvery microtrichia stripe very narrow, limited to extreme margin of eye, continuous with very narrow microtrichose parafacial; gena slightly darker brown below narrowest part of lower eye margin; postocular microtrichia slightly wider than parafrontal microtrichose stripe in lateral view, extending from base to middle of eye; face concolourous with face laterally, slightly paler medially; supracervical setulae very pale. Antenna with postpedicel greyish brown, yellowish brown on inner and medially surfaces. Proboscis with yellowish brown palpus. Thorax: yellowish brown; scutum mostly thinly microtrichose without pair of vittae; lateral margin of scutum and postpronotal lobe broadly shiny; scutellum concolourous with scutum; mediotergite without distinct stripe; pleura shiny, anepisternum and katepisternum lightly clothed in whitish microtrichia when viewed obliquely; whitish microtrichia above fore coxa; 2 anepisternal setae. Wing ( Fig. 6 View FIGURES 6–13 ) entirely brown, slightly tapered apically, with 3 hyaline crossbands; some faded or paler regions between bands; costal cell without hyaline band at humeral break, with narrow hyaline band at extreme apex of cell in line with discal hyaline crossband; oblique subbasal hyaline crossband very short, extending to basal fifth of cell dm; discal hyaline crossband short, continuous from R 1, reaching posterior margin of cell dm, not extending beyond level of crossvein r-m in cell dm; subapical hyaline crossband nearly straight, anterior end not extending proximal to crossvein r-m; crossvein dm-m straight to slightly arched; anal lobe developed; calypter with white margin. Abdomen: yellowish brown. Male terminalia ( Figs 14, 15 View FIGURES 14–17 ): inner surstylus with tight cluster of 4–5 thick prensisetae, inner margin concave; outer surstylus slender, slightly tapered and arched, slightly longer than length of inner surstylus, with narrow apex ( Fig. 10 View FIGURES 6–13 ); subepandrial sclerite with strong dark setae. Cercus with short setae; apical margin slightly pointed. Phallus short, with 2 loops.

Distribution. This species is known exclusively from northern California ( Fig. 24 View FIGURES 24–26 ).

Remarks. See comments under T. cuneata   .


California State Collection of Arthropods


Tavera, Department of Geology and Geophysics


California Academy of Sciences


Smithsonian Institution, National Museum of Natural History


Departamento de Geologia, Universidad de Chile