Boletina arctica Holmgren, 1872

Salmela, Jukka, Suuronen, Anna & Kaunisto, Kari M, 2016, New and poorly known Holarctic species of Boletina Staeger, 1840 (Diptera, Mycetophilidae), Biodiversity Data Journal 4, pp. 7218-7218 : 7218

Boletina arctica Holmgren, 1872

Boletina arctica Holmgren, 1872: 105 ( Holmgren 1872)

Boletina arctica var. Edwards, 1933: 612 ( Edwards 1933)

Boletina arctica nec Rübsaamen, 1898: 104 ( Rübsaamen 1898), (= Boletina digitata Lundström)

Materials

Type status: Other material. Occurrence: recordedBy: H.K. Rutz; individualCount: 3; sex: male; Location: country: Canada; verbatimLocality: Axel Heiberg Island, Wh. Glacier; verbatimLatitude: 79.416; verbatimLongitude: -90.750; verbatimCoordinateSystem: WGS84; Event: eventDate: 1963-7-26; Record Level: institutionCode: CNC Type status: Other material. Occurrence: recordedBy: H.K. Rutz; individualCount: 4; sex: male; Location: country: Canada; verbatimLocality: Axel Heiberg Island, Wolf R.; verbatimLatitude: 79.416; verbatimLongitude: -90.750; verbatimCoordinateSystem: WGS84; Event: eventDate: 1963-7-25; Record Level: institutionCode: CNC Type status: Other material. Occurrence: recordedBy: H.K. Rutz; individualCount: 1; sex: male; Location: country: Canada; verbatimLocality: Axel Heiberg Island, Wolf R.; verbatimLatitude: 79.416; verbatimLongitude: -90.750; verbatimCoordinateSystem: WGS84; Event: eventDate: 1963-7-24; Record Level: institutionCode: CNC Type status: Other material. Occurrence: recordedBy: H.K. Rutz; individualCount: 3; sex: female; Location: country: Canada; verbatimLocality: Axel Heiberg Island, Wolf R.; verbatimLatitude: 79.416; verbatimLongitude: -90.750; verbatimCoordinateSystem: WGS84; Event: eventDate: 1963-7-25; Record Level: institutionCode: CNC Type status: Other material. Occurrence: recordedBy: H.K. Rutz; individualCount: 1; sex: female; Location: country: Canada; verbatimLocality: Axel Heiberg Island, Wh. Glacier; verbatimLatitude: 79.416; verbatimLongitude: -90.750; verbatimCoordinateSystem: WGS84; Event: eventDate: 1963-7-26; Record Level: institutionCode: CNC Type status: Other material. Occurrence: recordedBy: H.K. Rutz; individualCount: 1; sex: female; Location: country: Canada; verbatimLocality: Axel Heiberg Island; verbatimLatitude: 79.416; verbatimLongitude: -90.750; verbatimCoordinateSystem: WGS84; Event: eventDate: 1963-8-4; Record Level: institutionCode: CNC

Description

Redescription

Male: Head, mouthparts and palpomeres black. Scape, pedicel and flagellomeres dark-brown - black. Scutum dark-brown, with scattered light setae. Pleura dark brown, mediotergite, laterotergite, anepimeron, anepisternum and preepisternum glabrous. Fore coxae, all femora and tibiae yellow, trochanters black, tarsomeres brown, claws black. Mid and hind coxae dark-brown. Wing length 4.8 mm. Sc1, Sc2, Rs, ta, tb and M-stem bare, apical halves of M1, M2 and CuA1, entire CuA2 and stem of CuA setose on dorsal surface. Sc1 ending in costa little before Rs. Costa extending beyond tip of R5 to approximately 1/3 of the distance between R5 and M1. Halteres pale yellow. Abdominal tergites and sternites dark-brown, bearing light hairs. 9th tergite black. Cercus ca. 1.4 times wider than long, having basally 3-4 irregular combs (i.e. rows of dark-brown, stout setae): total number of such setae 37-40. Apex of cercus with a distinct comb, number of setae 14-15. Sternal submedian appendages of gonocoxites short, apically rounded, diverging, pubescent (Fig. 11c). Gonocoxite apicomesally with two black spines (Fig. 11a). Inner branch of gonostylus pollex-like, bearing two long black apical setae and a black spine. Outer branch of gonostylus rectangular, widest subapically, with a modest apical peak (Fig. 11a, b). Mesal edge of gonostylus hairy. Parameres short and straight (Fig. 11c). Parameral apodemes + parameres resembling the letter L in lateral view (Fig. 11d). Aedeagus short and curved (Fig. 11d). Ejaculatory apodeme with basal projections. Gonocoxite internally with a narrow, pointed projection (Fig. 11a). Close to this projection are two hyaline projections, bearing weak bristles; this latter projection is part of aedeagal complex.

Distribution

Boletina arctica has been recorded from Greenland ( Holmgren 1872, Söli et al. 2015), Arctic Russia ( Zaitzev 1994) and Akpatok Island, Hudson Strait, low arctic zone of Canada ( Edwards 1933). Here we report the species from the high arctic zone, Axel Heiberg Island, Canada.

Taxon discussion

Given the rarity of this species, B. arctica has been illustrated rather frequently in taxonomic literature. The first to illustrate this species was Rübsaamen ( Rübsaamen 1898), but instead of B. arctica , he actually figured B. digitata Lundström (or some related species of this complex, see Suppl. material 1). Johannsen ( Johannsen 1911) copied Rübsaamen's illustration of B. arctica and gave no additional occurrence data. Later Lundström ( Lundström 1912) provided good figures, based on material loaned from ZMUC, Copenhagen, originally collected from Greenland. It is not clear whether a type specimen was examined, but most likely it was a non-type male, since the type material of B. arctica is not deposited in ZMUC (http://www.zmuc.dk/EntoWeb/collections-databaser/Diptera/Mycetophilidae%20all.htm). Hence, authors after Lundström have followed his interpretation of B. arctica . Edwards ( Edwards 1933) was actually the first to report this species from North America (Akpatok Island), he illustrated Boletina arctica var. According to Edwards, his specimens were slightly different from a male specimen collected from Greenland. However, such differences on the outline of the gonostylus are due to aspect of the gonostylus to the viewer (Fig. 11b). Boletina arctica was also illustrated by Zaitzev ( Zaitzev 1994) and recently by Söli et al. ( Söli et al. 2015).

The species possesses some unique characters that have been misinterpreted in the literature. First of all, B. arctica has no sharply pointed parameres (cf. Edwards 1933, p. 612). Lundström, Edwards and Zaitzev have illustrated these sharply-pointed projections that actually stem from the inner lateral margin of the gonocoxite. Furthermore, close to these projections lie two spinose, hyaline projections that orginate from the aedeagal complex. The parameres themselves are inconspicuous, short and straight.