Eucelatoria borealis Burington 2022, sp. nov.

Eucelatoria borealis sp. nov.

(Figs 1H, 7, 29, 52, 74, 97, 112, 126, 142, 159, 173)

Type material. Holotype ♂, labeled “QUE Cté Vaudreuil / summit Mt. Rigaud / 30. VII. 1997 / D.M.Wood 220m ”, “ HOLOTYPE / Eucelatoria / borealis/ Z.L. Burington [red label]”, “ZLB_E.Ferox 00037” (DMW).

Allotype ♀, labeled: “QUE Cté Vaudreuil / summit Mt. Rigaud / 28. VI. 1996 / D. M. Wood 220 m ”, “ALLOTYPE/ Eucelatoria / borealis/ Z.L. Burington [red label]”, “ZLB_E.Ferox 00022” (DMW).

Paratypes, 13 ♀♀ and 15 ♂♂. Canada — British Columbia: 1 ♀, “Mission City, B.C./ 28 -VI- 1953 / W. R. M. Mason ”, “ PARATYPE / Eucelatoria / borealis/ Z.L. Burington [yellow label]”, “ZLB_E.Ferox 00026” (CNC). New Brunswick: 1 ♂, “Chamcook, N.B./ 9-VII-1965 / G.E. Shewell ”, “Chamcook Hill/ Summit. 637′”, “ZLB_E.Ferox 00027” (DMW). Ontario: 1 ♀, “ St. Lawrence Is. / Nat. Park; ONT./ Grenadier I. Center ”, “ 29-VII-1975 / R.J. Mc-Millan/ Malaise Trap / Code 2-115K-92”, “ZLB_E.Ferox 00019” (CNC). 3 ♀♀ and 1 ♂, as previous except “ 5- VIII-1975 / E. Sigler / Malaise Trap / Code 2-184B-11”, “ZLB_E.Ferox 00020” [♀]; “ 6-VII-1975 / R.J. McMillan / Malaise Trap / Code 2-195M-18”, “ZLB_E.Ferox 00021” [♀]; “ 29-VII-1995 / R.J. McMillan / Malaise Trap / Code 2-115K-79”, “ZLB_E.Ferox 00024” [♀]; and “ 14-VII-1975 / E. Sigler / Malaise Trap / Code 2-42P-129”, “ZLB_ E.Ferox 00032” [♂; genitalia in vial under specimen] (CNC). 1 ♀, “ St. Lawrence Is. / Nat. Park, ONT./ Thwartway Is.”, “22: VII: 1976/ W. Reid/ Code 4182V-9”, “ZLB_E.Ferox 00031” (CNC). 1 ♀, “Sheffield - ONT./ Wentworth Co. / 5 -IX -1960 / Taylor & Wood”, “SLIDE/ E5580522A/ No.”, “ZLB_E.Ferox 00041” [terminalia in vial under specimen] (DMW). 1 ♀, as previous except “ 25 -VII - 1960 ”, ZLB_E.Ferox 00042”. Quebec: 1 ♀, “Mi. 61 Rte. 58/ La Verendrye/ Prov. Pk. Que. / 20-VIII.1965 / D.M.Wood ”, “Photo by A.J./ Fleming 2010/ 2010-1049”, “ZLB_E.Ferox 00023” (CNC). 4 ♂♂, “QUE Cté Vaudreuil/ summit. Mt. Rigaud / 22. VII. 1997 / D.M. Wood 220m ”, “ZLB_E.Ferox 00327”, “00325”, “00036”, and “00038” (DMW). 1 ♂, as previous except labeled “doesn’t fit either species [handwritten]”, “ZLB_E.Ferox 00043” (DMW). 2 ♂♂, as previous except “ 27.VII.1995 ”, “ZLB_E.Ferox 00323”, “00322”, the second labeled “ Eucelatoria / texana [handwritten]” (DMW). 2 ♂♂, as previous except “24. VI.98 (early year)”, “ZLB_E.Ferox 00035” and “00034” (DMW). 3 ♂♂, as previous except dates “19.VI.98 (early year)”, “ 21. VII. 1995 ”, and “ 16–18.VII. 1967 ”, specimen IDs “ZLB_E.Ferox 00044”, “00324” (DMW), and 00033” (CNC), the final specimen with handwritten label “Collected same loc/ CNCDC620-11”. USA — Maryland: 1 ♀, “Beltsville/ 14.7.16 [1916] Md”, “RCShannon/ Coll”, “USNM ENT 00040026”, “ZLB_E.Ferox 00347” (USNM). Ohio: 1 ♀, “Amherst, Ohio / July, 1933”, “H J Reinhard/ Collector”, “ Xiphomyia / texana/ Reinhard Coll”, “SLIDE/ ES6807-11E/ No.”, “ZLB_E.Ferox 00025” [terminalia in vial below specimen] (CNC). West Virginia: 1 ♀ and ♂, “WV Pocahontas Co. / Cranberry Glades / 13.VII. 1999 / G.&D.M.Wood ”, “ZLB_E.Ferox 00040” [♀] and “000326” [♂] (DMW). 1 ♀, as previous except locality “Briery Knob/ road”, date “17.VIII.99”, and specimen ID “ZLB_E.Ferox 00039” (DMW).

Recognition. This species is distinguished from other members of the E. ferox group by the diffuse, nearly absent tomentum of the thoracic notum rendering the thoracic vittae indistinct. It is most similar to E. texana in the subparallel paddle-shaped surstylus, the digitiform cercus in lateral view, the relatively short female piercer, and the usually gray thoracic and abdominal tomentum, but differs in addition to the dark thorax in having a partially yellow parafacial, an even shorter female piercer, weak ocellar setae, and a more rounded basal lobe on the surstylus.

Etymology. From the Latin boreas, meaning “the north wind”, as E. borealis sp. nov. has the most northern distribution of all sword flies.

Description. [Described from 14 ♀♀ and 16 ♂♂; head measurements from 4 ♀♀ and 3 ♂♂.] Length 5.8–7.5 mm (mean = 6.6 mm).

Head. Fronto-orbital plate, vertex, upper half of post-ocular plate tomentum pale yellow, at times appearing almost gray. Parafacial pale yellow on upper half to upper three-fourths, on lower area ash-gray. Gena, postgena, occiput, and lower half of post-ocular plate tomentum ash-gray. Pale occipital setae dirty gray. Ocellar setae weak, one-half or less the length of posterior reclinate orbital seta. Gena with 3 setea, subvibrissal ridge with 1 setae. Facial ridge with setulae on lower third or less. Postocellar setae one-half to three-fourths length of ocellar setae. Paravertical seta one-half length of postocellar seta. Outer vertical seta not differentiated in male, one-fourth to one-half length of inner vertical in female. Reclinate orbital setae 3. Frontal setae 3–5, last frontal setae level with or slightly past base of arista. Eye apparently bare or with very few, short setulae. Eye height 0.85 height head. Postpedicel length 0.4–0.7 (mean = 0.5) height of head. Facial ridge length 0.50–0.60 (mean = 0.56) height of head. Parafacial width 0.06–0.10 (mean = 0.08) lateral length of head. Pedicel 0.2–0.4 (mean = 0.3) length of postpedicel. Postpedicel 2.0–4.0 times width of parafacial in lateral view. Vertex 0.25–0.40 (mean = 0.30) width of head in dorsal view. Palpus yellow to tan at apex, darker at base; subcylindrical, slightly more dilated at tip on female; with short, stout dorsoapical setae.

Thorax. Dorsomedial length 1.3 dorsal width of thorax. Lateral tomentum fine diffuse gray, most visible on katepisternum, on some specimens seeming absent from anepisternum. Dorsal tomentum yellow to gray, dense on postpronotum, thinning medially and posteriorly on mesonotum except for a small posteromedial triangle, such that central area of thorax seems shining black. Presutural outer vitta triangular, indistinct. Postsutural outer vitta indistinct to apparently absent. Inner thoracic vittae linear, indistinct on presutural area except for anterior margin, indistinct to apparently absent on postsutural area. Scutellar dorsal tomentum yellow-gray to gray, diffuse, covering apical half or more. Postpronotum with 3 setae, occasionally with a fourth seta much weaker than the others. Presutural area with 2 supra-alar setae, the anterior seta weak. Postsutural area with 3 dorsocentral setae. Scutellum with 1 pair discal setae. Fore tibia with 2–3 posterodorsal setae. Wing hyaline. Calypters tan to cream colored.

Abdomen. Cuticle and setulae entirely black. Dorsal tomentum bands diffuse gray, occasionally with yellow tinge, one-fourth to one-third length of T3–5, with faint median vitta. Ventral tomentum bands gray, their extent as in dorsal bands. T4 with 1 pair of median marginal setae and 3–4 strong erect lateral setae, such that the marginal setae appear to form a widely spaced row.

Male terminalia (Figs 126, 142, 159). Sternite 5 basal plate with median teeth separated 0.2 width of basal notch; apical lobes 1.3 times length of basal plate. Postgonite broadly rounded, with emargination depth subequal width of postgonite at mid length. Surstylus flipper-shaped, bluntly pointed to subquadrate at tip, gradually curved at posterior base, nearly parallel sided along mid length. Cercus in lateral view expanded at base, subcylindrical along midsection, apex rounded to pointed tip; in caudal view gradually narrowed from base, somewhat expanded at apex. Upper lobe bluntly rounded, 0.3 length of cercus. Median section 0.4 length of cercus. Apical cleft narrow, nearly parallel sided, 0.3 length of cercus. Syncercus apex width in caudal view 0.46 width of syncercus base.

Female terminalia (Figs 97, 112). Piercer generally extending to middle of T4, in lateral view gradually curved near base, more strongly curved on apical third; in posterior view, parallel sided on basal third, gradually narrowed to tip.Aculeate lobe 1.7 times height of segment seven base. End tergite thin, rectangular, four times as long as wide. Cercus with 5 setae; ventral elongation subequal length of cercus. Postgenital plate with 12 setae.

Host(s). Unknown.

Geographic extent and seasonal occurrence. Eucelatoria borealis sp. nov. is the most northern of all the E. ferox group species, with most individuals collected in southern Ontario and Quebec (Fig. 173). It has been found as far North and West as southern British Columbia, as far east as New Brunswick, and as far south as West Virginia.

Discussion. This species was previously included as part of the geographic extent of E. texana (O’Hara & Wood 2004), but it is here separated by its distinctive characters, namely, the dark colored thoracic dorsum nearly devoid of tomentum, the faint or nearly absent thoracic vittae on everything except the anterior edge of the presutural area, the faint yellow coloration of the dorsal half of the parafacial, and the shorter piercer length of the female. The subparallel margins of the cercus past mid length in lateral view suggest a close relationship with E. texana and E. borealis sp. nov., as opposed to the dilated apex of the cercus in E. sabroskyi sp. nov. The dark thoracic coloration may seem similar side by side to the several species with triangular tomentum on the presutural area (e.g., E. kopis sp. nov.), but these species are entirely Neotropical. Males may be confused with E. auriceps or E. texana if head and thorax coloration is ambiguous, but generally the posterior margin of the surstylus in E. borealis sp. nov. is less rounded than in E. auriceps and the basal lobe is more rounded than in E. texana. If localities such as the Thousand Islands, Ontario, and Mt. Rigaud, Quebec, are any indication, this species is associated with a cooler temperate forest element than the related E. auriceps. The apparently disjunct individual in British Columbia is surprising, but genetic evidence (Fig. 1) suggests it belongs to the same species. Genetic support for a sister species is absent, but there is low support for a close relationship between E. borealis sp. nov., other North American species, and several Central American species of the E. gladiatrix subgroup.