Megophthalmidia saskia, Kerr, Peter H., 2014

Kerr, Peter H., 2014, The Megophthalmidia (Diptera, Mycetophilidae) of North America including eight new species, ZooKeys 386, pp. 29-83 : 62-66

Megophthalmidia saskia sp. n. Figs 82-92

Type material.

Holotype: ♂, "USA: CA: Marin: Pt. Reyes NS, LimantourRd, 2.6mi S BearVallRd, 2mMT, 38.0526°N,-122.8263°W, 13. iii– 1.v.2012 P. H. Kerr, C. J. Borkent, CSCA12L022" / "HOLOTYPE 12J607, Megophthalmidia saskia ♂, Kerr, 2014" [red label]. Deposited in CSCA, complete specimen in excellent condition, mounted on gray point (Fig. 82). See Fig. 107 for image of type locality.

Paratypes: ♀, "USA: CA: Humboldt Co., Humboldt Bay NWR, Lanphere Dunes, MT#3 (6m), ~6masl, 40°53.421'N, 124°08.601'W 10. iv– 18.viii.2008 P.H. Kerr, P.Haggard CSCA09L107" [CSCA; # 09E102]; 2 ♀♀, "USA: CA: Humboldt Co., Prairie Creek SP, Cal-Barrel Rd. trailhd, 41.3828°N, 123.9979°W, 300masl, 2. vi– 25.vii.2009 P. Kerr & O. Lonsdale, 2mMT, CSCA09L519" [CSCA; numbers 09D513, 13N400 (Fig. 82)]; 2 ♂♂, 3 ♀ ♀ "USA: CA: Marin: Pt. Reyes NS, MtVisionRd, 1.8mi E SFDrakeBlvd 6mMT, 38.1013°N,-122.8878°W 280masl, 13. iii– 1.v.2012, P. H. Kerr & C. J. Borkent, CSCA12L023" [CSCA; specimen numbers 12J951 (♂, Figs 84-92), 12J606 (♂), 12J450 (♀), 13N398 (♀),13N399 (♀)]; ♂, "USA: CA: Sonoma Co., Annadel SP, 0.9mi from park lot, Richardson trail, 38°26.11'N, 122°36.67'W 220masl, 6m MT#3, 17.v-7.vi.2007 P. Kerr & S. Blank, 07LOT196" [CSCA; # 07y537]; 2 ♂♂, "USA: CA: Marin: Pt. Reyes NS, MtVisionRd, 1.8mi E SFDrakeBlvd 6mMT, 38.1013°N,-122.8878°W 280masl, 13. iii– 1.v.2012, P. H. Kerr & C. J. Borkent, CSCA12L023" [CSCA; # 12J578, # 13M285 (Fig. 83); both in alcohol]; ♂, "USA: CA: Sonoma Co., Annadel SP, 0.9mi from park lot, Richardson trail 38°26.11'N, 122°36.67'W 220masl, 6m MT, 3-26.iv.2007 P. Kerr & S. Blank 07LOT029" [Locality Fig. 103; CSCA; # 12K736, in alcohol].

Diagnosis.

Megophthalmidia saskia is easily separated from its putative congeners by its having a setose frons, wing vein CuP (Fig. 83), dark haltere, and distinctive genitalia (Figs 84-89).

Description.

Male. Body length: 2.5-2.7, 2.6 [2.6] mm (n=3). Wing length: 2.5-2.7, 2.6 [2.6] mm (n=3).

Coloration (Fig. 82). Head, antennae, face, clypeus and labrum dark brown to black; palps and labellum light brown to brown. Thorax dark brown to black throughout; scutum setae black. Coxae light brown to brown, anterior surface of fore coxae darker; femora becoming gradually darker dorsoapically, tibiae brown to dark brown (hind tibia darkest), tarsi brown; hind tibial comb dark brown, preceded by one longer dark brown seta. Wing hyaline without markings, wing veins dark brown; haltere stem and knob dark brown. Abdominal segments concolorous dark brown to black, except sternites 1-3 usually paler brown. Terminalia dark brown to black.

Head. Ocelli slightly raised, not arranged in a line (median ocellus clearly anterior of lateral ocelli); median ocellus very small, approx. 0.2 × size of lateral ocelli; lateral ocellus located approx. 3 × diameter of ocellus from eye margin, separated from median ocellus by approx. twice its own diameter. Frons microtrichose and setose, flattened. Eyes with microsetae, which are approximately as long as width of facet. Antennal length 1.0-1.1, 1.0 [1.1] mm (n=3) (approx. 1 × length of head and thorax). Face nearly as wide as long, microtrichose, bearing black setae medially and along ventral margin; clypeus microtrichose, without setae; labrum microtrichose, without setae. Palpus with four palpomeres; palpomere 1 barrel-shaped, without setae; other palpomeres with golden brown to dark brown setae; palpomere 2 bearing small pocket of sensilla; palpomere 1 subequal in length to palpomere 2; palpomere 3 length slightly shorter than combined length of palpomeres 1 and 2; palpomere 4 length 0.75 –1× combined lengths of palpomeres 1-3.

Thorax. Dorsum with evenly-distributed, short, appressed setae, bearing longer setae only along lateral and posterior margins. Antepronotum, proepisternum, and laterotergite bearing setae; remaining lateral thoracic sclerites bare. Wing venation as in Fig. 83; costal vein extends beyond R5, approx. two-thirds distance between R5 and M1; R1, M1, M2, CuA1, and CuA2 with setae on upper surface (lacking setae on M1 + M2). CuA1 usually reaching wing margin (Fig. 83 shows irregularity in this respect). Wing vein A1 absent, CuP present as prominent fold with at least some apparent brown coloration (sclerotization).

Dorsum with evenly-distributed, short, appressed setae, bearing longer setae only along lateral and posterior margins. Antepronotum, proepisternum, and laterotergite bearing setae; remaining lateral thoracic sclerites bare. Costal wing vein extends beyond R5, approx. two-thirds distance between R5 and M1; cubital fork below, at same level or distad of r-m base; R1, M1, M2, CuA1, and CuA2 with setae on upper surface (lacking setae on M1 + M2).

Male genitalia (Figs 84-92). Epandrium narrow laterally, without setae medially, narrowly emarginate at center, with posterior margin bearing 6-8 posteriorly-directed strong setae, lacking posterior processes (Figs 84-86). Gonocoxites with anteroapical expansion, centrally-attached dorsal apodeme and bearing short ventral process (Figs 87-89). Aedeagus reduced, without aedeagal fork (Figs 90-92).

Female. Body length: 2.8-3.5, 3.2 mm (n=6). Antennal length: 0.7-1.1, 0.9 mm (n=5). Wing length: 2.6-3.5, 3.1 mm (n=6).

Coloration (Fig. 82). Same as male; cerci light brown to brown.

Etymology.

The species name “saskia,” a noun in apposition, is given in honor of my daughter, Saskia Ana Kerr, born April 20, 2013. Just as Saskia is to our family, Megophthalmidia saskia is a special addition to this group.

Discussion.

The male terminalia of Megophthalmidia saskia is unlike any other Megophthalmidia species in North America. Furthermore, Megophthalmidia saskia shares a number of characters with Mohelia and Aphrastomyia that until now, have not been observed in Megophthalmidia . These characters include wing vein CuP present and frons bearing setae. As such, Megophthalmidia saskia may be an important entity for understanding character evolution across the group containing Megophthalmidia , Mohelia , and Aphrastomyia . Megophthalmidia found elsewhere (e.g., Megophthalmidia crassicornis (Curtis) of Europe and Megophthalmidia divergens Edwards of the neotropics) show a degree of variation that implicitly defines the genus as a dumping ground of putatively related species that are not Aphrastomyia . Mohelia is also related, but its status is poorly understood and representative specimens were not available for this study. While Megophthalmidia saskia clearly represents a distinct evolutionary divergence, it is premature to construct additional genus-level concepts until the entire group is studied in detail, within a broader phylogenetic and biogeographic context. Such work is in development and ongoing.