Cratyna (Diversicratyna) palustricola, Menzel & Salmela & Vilkamaa, 2020

Menzel, Frank, Salmela, Jukka & Vilkamaa, Pekka, 2020, New species and new records of black fungus gnats (Diptera: Sciaridae) from the Viidumäe Nature Reserve, Estonia, European Journal of Taxonomy 720, pp. 62-76 : 64-66

Cratyna (Diversicratyna) palustricola sp. nov.

urn:lsid:zoobank.org:act:4E4B22E3-0BED-4E10-92CD-F121EE7AF3E4

Figs 1–2

Diagnosis

Rather small species (wing length = 1.6–1.7 mm) with three-segmented palpi. Gonostyli narrowed toward apex, with long apical tooth and 4–6 megasetae. Tegmen conical, broader than long.

Etymology

The name, a noun in apposition, is derived from the Latin words ʻ palustris ʼ (ʻmarshyʼ) and ʻ– cola ʼ (ʻinhabitantʼ), referring to the habitat of the species.

Material examined

Holotype

ESTONIA • ♂; Saaremaa Island, Viidumäe Nature Reserve ; 58.2966° N, 22.0863° E; 15 Aug.–11 Sep. 2002; T. Talvi leg; Malaise trap; rich fen; with one male of Corynoptera postforcipata Rudzinski, 1993 on the same slide; MZH.

Paratypes

ESTONIA • 1 ♂; same collection data as for holotype; 12Apr.–15 May 2002; with 1 male of Claustropyga brevichaeta (Mohrig & Antonova, 1978) on the same slide; MZH • 1 ♂; same collection data as for holotype; 17 Jul.–15 Aug. 2002; with 2 males of Corynoptera unidentata (Hippa & Vilkamaa, 1994) on the same slide; SDEI • 2 ♂♂; same collection data as for holotype; 16 Jun.–17 Jul. 2002; with 1 male of Lycoriella lundstromi (Frey, 1948) on the same slide; MZH .

Description

Male

HEAD. Brown. Maxillary palpus very pale brown. Antenna concolorous, pale brown. Eye bridge 3 facets wide. Face with 6 scattered dark setae of various length. Clypeus with 1 dark seta. Maxillary palpus with 3 segments; segment 3 longest, segment 2 shortest; segment 1 with one long sharp seta, with dorsal pit of sensilla. Fourth antennal flagellomere 2.4 × as long as wide, neck shorter than broad; longest setae shorter than width of flagellomere.

THORAX. Unicolorous brown. Setae dark. Anterior pronotum with 2 setae. Prothoracic episternum with 5–6 setae. Scutellum with 4 long setae and some short setae.

WING. Length = 1.6–1.7 mm. Anal lobe very small. Width/length = 0.35–0.40. R1/R = 0.60. c/w = 0.60–0.75. r-m shorter than bM, both veins non-setose. Halter pale brown.

LEGS. Yellowish. Coxal setae dark. Fore tibial organ with pale vestiture, forming indistinct patch. Fore tibial spur slightly longer than tibial width.

ABDOMEN. Pale brown, paler than thorax. Setae dark and rather short. Hypopygium ( Figs 1 , 2A ) brown, as abdomen. Gonocoxae longer than gonostyli; ventral setosity of gonocoxae normal, sparse. Gonostyli ( Figs 1 , 2B ) elongated, narrowed towards apex, mesial side slightly impressed; setosity sparse; with long apical tooth, with 4–6 megasetae (subequal in size, slender, straight); apically with long curved seta. Tegmen unmodified, conical, broader than long, with small aedeagal teeth; aedeagal apodeme short.

Taxonomic remarks

Cratyna palustricola sp. nov. belongs to the subgenus Diversicratyna Menzel & Mohrig, 1998 . The new species resembles Cratyna spiculosa ( Rudzinski, 1993) and Cr. unispinula (Mohrig & Menzel, 1992) in having a narrow gonostylus with a long apical tooth and a group of apical and/or subapical megasetae (cf. Rudzinski 1993: 286, figs 11–14; Mohrig & Menzel 1992: 3, fig. 3a–d). Cratyna palustricola sp. nov. and Cr. unispinula are similar in having the megasetae very narrow (thickened in Cr. spiculosa ) and in having the maxillary palpus with three segments (two in Cr. spiculosa ). Cratyna palustricola sp. nov. differs from Cr. unispinula in having a broader gonostylus, with its subapical megasetae more numerous (4–7 vs 2) and the basalmost ones placed nearly at the middle of the gonostylus. Furthermore, Cr. palustricola sp. nov. has a modified long seta on the dorsal side of the gonostylus, not a megaseta as Cr. unispinula sometimes does (see Menzel & Mohrig 2000).

By its gonostylus, Cratyna (Diversicratyna) palustricola sp. nov. resembles Corynoptera salmelai Vilkamaa, Hippa & Heller, 2013 and Corynoptera spiciforceps Vilkamaa, Hippa & Heller, 2013 . Cratyna palustricola is similar to C. spiciforceps in having the gonostylus evenly narrowed towards apex, whereas C. salmelai has it bulged medially. Cratyna palustricola is similar to C. spiciforceps and differs from C. salmelai in having the tegmen rounded apically and in having a sensory pit on the 1 st palpal segment, whereas C. salmelai has sharp apicolateral teeth on its tegmen and the 1 st palpal segment with a patch of sensilla. Furthemore, C. spiciforceps has an elongated seta medially on its gonostylus. Cratyna (Diversicratyna) palustricola sp. nov. differs from both species of Corynoptera in having 2 megasetae, not normal setae, on the dorsal side of the apical tooth of the gonostylus, confirming its generic placement.

Figures

Fig. 1. Cratyna (Diversicratyna) palustricola sp. nov., holotype (MZH), hypopygium, ventral view.

Fig. 2. Cratyna (Diversicratyna) palustricola sp. nov. A. Hypopygium (holotype, MZH), ventral view. B. Gonostyli (paratype, MZH), ventral view. Scale bars: A = 130 µm; B = 40 µm.