Grzegorzekia kerri Fitzgerald, 2019

Fitzgerald, Scott J., 2019, The Nearctic species of Grzegorzekia Edwards (Diptera: Mycetophilidae), Zootaxa 4623 (3), pp. 163-174 : 164-165

Grzegorzekia kerri Fitzgerald n. sp.

Figs. 1–6 , 11

Diagnosis. The combination of the presence of a mid-tibial sense organ ( Fig. 6 ), abdominal tergites with narrow pale posterior bands ( Fig. 1 ), and the structure of the terminalia ( Figs. 3–5 ) will distinguish males of G. kerri n. sp. from all congeners. Females can be distinguished by the combination of the following characters: abdominal tergites with narrow pale posterior bands (females of G. collaris may have pale coloration only at the anterolateral areas of some or all of tergites 2–7) and sternite 8 medially longitudinally divided and apically lobate with strong spine-like setae ( Fig. 11 ).

Description. Male. Body length: approx. 4.0 [4.0] mm (n=2). Head. Brown with thin grey pollinosity and short brown setae. Three ocelli, lateral ocelli slightly less than or equal to their diameter distant from the eye margin. Antennae ~ 1.5 times as long as head + thorax. Pedicel and scape short, thick, beige and brown, scape with grey pollinosity. Fourteen elongate, dark brown flagellomeres shortening distally, basal flagellomere five times as long as wide. Thorax brown, scutum matte dark brown with grey pollinosity both laterally and forming narrow longitudinal median and dorsocentral stripes converging posteriorly. Short, brown acrostichal and dorsocentral setae and longer, darker, lateral setae present. Pleura brown, with beige highlights and thin grey pollinosity. Antepronotum with setae, propleuron and pleural sclerites, including laterotergite and mediotergite, bare. Legs. Femora beige-brown, tibia light brown, but slightly darker than femora, tarsi brown. Mid tibia slightly swollen just basal to half way point with a thin whitish elongate sensory area along dorsal surface ( Fig. 6 ). Legs without strong setae, fore tibia without macrosetae, mid tibia with several tiny anterior setae, hind tibia with or without several tiny anterior and dorsal setae. Hind basitarsus slender, elongate, parallel-sided, approximately twenty-one times as long as wide. Tibial spurs 1:2:2. Tarsal claw with a basal tooth, empodia undeveloped. Wing ( Fig. 2 ). 5.5–6.0 [6.0 mm] (n=2). Hyaline with dark maculae in the following areas: around radial cell, base of Rs, r-m, and stem of M, along length of CuA, and along all longitudinal veins starting at apical third of wing (on apical third of wing, pale areas between veins (as Fig. 2 ) are sometimes more infuscated leaving only very narrow pale areas). Veins brown, all with dorsal setae except: Sc (sometimes bare, sometimes with a few setae), base Rs, R 2+3, base and stem of M, CuP (either bare or with a few setae). Sc ending before base of Rs, sc-r ending near apex of Sc, but before level of posterior fork. Radial cell rectangular, R 4+5 distinctly bowed distally. Stem M more than twice as long as r-m. Posterior fork beginning basal to level of medial fork, arising just before level of base of r-m, base of M 4 often weak or detached at fork. Abdomen. Brown with narrow, bright-beige band on posterior edge of tergites 2–7, bands becoming interrupted medially on posterior tergites. Terminalia ( Figs. 3–5 ). Tergite nine broader than long with broad shallow v-shaped emargination on posterior edge ( Fig. 5 ). In lateral view, gonocoxite section II tapered to a single rounded lobe with an apicodorsal comb of closely-set spine-like setae. Aedeagus, paramere, and aedeagal guide very large, dominating terminalia in ventral view ( Fig. 3 ) and strongly projecting anteroventrally in lateral view ( Fig. 4 ). Aedeagus triangular in ventral view. Paramere with broad rounded lateral lobes in ventral view and paired posteriorly directed median keel ( Figs. 3–4 ). Gonocoxal lobes thin, curved, apically acute, sickle-like, with several long setae apically ( Fig. 3–4 ). Gonostylus absent. Gonocoxite section I essentially bare of setae, broad in lateral view ( Fig. 4 ), narrower and strap-like in ventral view ( Fig. 3 ). Gonocoxite section III a pair of small curved, digitate, apically setose lobes closely associated with gonocoxal apodeme ( Fig. 4 ). Cerci fleshy, apically rounded-truncate with setae. Hypoproct not strongly developed; a pair of small, fleshy, setose, digitate lobes ventral to cerci.

Female. Similar to male except as follows. Body 5.0 mm (n=1), wing 5.5 mm (n=1). Mid-tibial organ absent. Cerci beige, basal segment elongate, rectangular, apical segment small, rounded. Sternite 8 longitudinally divided medially, posteromedial edge of sternite prolonged into a pair of apically truncate lobes (one lobe on either side of the medial cleft) each bearing numerous spine-like setae ( Fig. 11 ).

Biology. The Oregon sites where adults of G. kerri have been collected are best characterized as low elevation patches of mixed woods, interspersed with areas cleared for pasture, agriculture, and residential development (Willamette Valley Ecoregion). All Oregon sites included Oregon White Oak (Quercus garryana Douglas; see biology section of G. quercus n. sp.). The four California specimens were collected in Malaise traps in wooded areas (Peter Kerr, pers. comm.).

In contrast to Palearctic congeners which, based on published records, appear to be active during the summer months, G. kerri n. sp. has been collected primarily during the fall and winter (November–February, with two records from a March–April Malaise trap) which makes up part of Oregon’s lengthy rainy season. Most of the collected specimens were taken by UV light or Malaise trap. If the species and/or genus is crepuscular, or even nocturnal, this might account for why members of this genus are uncommonly hand-collected.

Distribution. Presently known only from Oregon and California.

Etymology. The specific epithet honors my colleague and friend Dr. Peter Kerr whose consistently high-quality work and fantastic photographs have greatly improved our knowledge of western Nearctic fungus-gnats. Furthermore, Peter has been a great support to the author’s studies of the group.

Type Material. Holotype: Male ( Fig. 1 ), point-pinned [ CNCI], USA: Oregon: Benton Co., Corvallis , 1460 SW Allen Street, 44.5509 N, - 123.2700 W, 17 Nov. 2012, S. Fitzgerald [white label] / HOLOTYPE, Grzegorzekia kerri Fitzgerald [red label], terminalia dissected. Paratypes: USA: California: 1 male, 09E190 [in alcohol, CSCA], Amador Co., Indian Grinding Rock St. Pk. , firebreak nr. envtl camp, MT3 , 38º25.7’ N, 120º38.6’ W’, 715masl, 26.ii–3.iv.2008 P.H. Kerr, CSCA08 L334; 2 males, 08A176 [in alcohol, CSCA], 10F753 [pinned, CSCA], Sonoma Co., Annadel SP, 0.9mi from park lot, Richardson trail, 38º26.11’N 122º36.67’W 220masl, 6m MT , 29.xi.2007 – 10.i.2008 P.H. Kerr, 07LOT762; 1 male, 08A149 [pinned, CSCA], Sonoma Co., Annadel SP, Two Quarry trail, 0.5km from White Oak Dr. entrance, 38º26.11’N 122º36.67’W 220masl, 29.xi.2007 – 10.i.2008 P.H. Kerr ; Oregon: 1 male [ JSL-UOC], same data as HT except 19 Nov. 2012 ; 3 males, 4 females [ SFC], same data as HT except 3 Dec.–7 Feb. 2018, S. Fitzgerald, MT078 ; 2 females [ SFC], same data as HT except 44.550867, -123.270537, 7 Feb.–24 March 2018, S. Fitzgerald, MT081 ; 1 male [ SFC], same except 3 Nov.–3 Dec. 2017, MT075 ; 1 male, 2 females [ SFC], Benton Co., Corvallis, 3430 NW Deer Run St. , 44.601571, -123.314098, 23 Dec. 2017 – 7 Feb. 2018, S. Fitzgerald, MT079 ; 8 males, 3 females [ SFC], same as previous except 3 Nov.–3 Dec. 2017, MT076 ; 2 males [ SFC], same except 12 Mar.–20 April 2018, MT082 ; 1 male, 2 females [ SFC], Benton Co., Corvallis, oak woods S. of MLK Jr. park, 11 Oct.–3 Dec. 2017, 44.587000, -123.315031, S. Fitzgerald, MT081 ; 1 male [ OSAC _0001001429], Benton Co., Philomath, Woods Creek , 44º35’N 123º25’ W, 100m, 12 Dec. 1998, UV light, leg. AVZ Brower; 2 males [ OSAC _0001001430, 0001001431], Benton Co., Blakesley Creek , 44º36.5’N 123º23’W, 300m, 6 Jan. 2002, UV light, leg. AVZ Brower/DD Judd; 1 male [ OSAC _0001001433] , 1 female [ OSAC _0001001432], same except 8 Jan. ; 2 males [ OSAC _0001001434, 0001001435], same except 10 Jan. ; 1 male [ OSAC _0001001436], same except 10 Feb. ; 1 male [ OSAC _0001001437], same except 24 Nov. 2000 ; 1 male [ OSAC _0001001438], same except 5 Feb. 2001 ; 1 male [ OSAC _0001001439], same except 16 Nov. 2001 .

Figures

FIGURE 1. Grzegorzekia kerri n. sp., holotype male, habitus. Scale bar = 5 mm.

FIGURE 2. Grzegorzekia kerri n. sp., wing. Scale bar = 1 mm.

FIGURES 3–6. Grzegorzekia kerri n. sp., 3–5. male terminalia. 3. Ventral view. Scale bar = 0.5 mm. 4. Lateral view. Scale bar = 0.5 mm. 5. Dorsal view. Scale bar = 0.5 mm. 6. Male mid-tibial sensory organ, dorsal view (anterior setae seen at left). Scale bar = 0.26 mm. Abbreviations: aed, aedeagus; aed g, aedeagal guide; cer, cerci; com, comb of spine-like-setae; gc I, gonocoxite section 1; gc II, gonocoxite section 2; gc III, gonocoxite section 3; gc lb, gonocoxal lobe; par, paramere; to, tibial organ; T9, tergite 9.

FIGURES 10–12. Female terminalia, ventral view. 10. G. collaris. Scale bar = 0.33 mm. 11. G. kerri n. sp. Scale bar = 0.5 mm. 12. G. quercus n. sp. Scale bar = 0.25 mm. Abbreviations: S8, sternite 8.