Megophthalmidia radiata,

Kerr, Peter H., 2014, The Megophthalmidia (Diptera, Mycetophilidae) of North America including eight new species, ZooKeys 386, pp. 29-83: 59-62

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Megophthalmidia radiata

sp. n.

Megophthalmidia radiata  sp. n. Figs 72-81

Type material.

Holotype: ♂, "USA: CA: San Luis Obispo Co., UC Rancho Marino Res., Malaise, 35.5391°N,-121.0790°W, 9-25.iv.2009 M.S. Caterino, CSCA12L333" / "HOLOTYPE 13M301, Megophthalmidia radiata  ♂, Kerr, 2014" [red label]. Deposited in CSCA, mounted on gray point, missing mid and hind right legs, otherwise in excellent condition; specimen not dissected (Fig. 72).

Paratypes (all bearing blue paratype label): 3 ♂♂, ♀, same locality as holotype [SBMNH # 13M345 (♂); CSCA, specimen numbers 13M318 (dissected ♂, Figs 73-81), 13M343 (♂), 12M344 (♀, Fig. 72)]; ♂, "USA: CA: San Luis Obispo Co., UC Rancho Marino Res., Malaise, 35.5392°N,-121.0813°W, 15. iv– 7.v.2009 M.S. Caterino CSCA13L250" [CSCA; # 13M787].


Megophthalmidia radiata  sp. n. may be confused with several Nearctic congeners that also have a brown thorax. Among these, it is most similar to Megophthalmidia ignea  , Megophthalmidia perignea  , and Megophthalmidia misericordia  on account of having broad posterior epandrial processes. Megophthalmidia radiata  has thicker posterior epandrial processes at their base than any of its congeners, including Megophthalmidia ignea  and Megophthalmidia misericordia  however, a character which is especially noticeable in lateral view (Fig. 73). The posterior epandrial processes are also very narrowly separated at their base (Fig. 74). The form of the adeagal complex is also diagnostic for this species (Figs 79-81).


Male. Body length: 2.6-2.9, 2.8 [2.9] mm (n=4). Wing length: 2.8-3.1, 3.0 [2.9] mm (n=4).

Coloration (Fig. 72). Male. Head dark brown; antennal scape, pedicel and flagellomeres brown to dark brown; face dark brown, clypeus and labrum brown to dark brown; palps and labellum cream-colored, pale yellow, to light brown (palpomeres 1-3 usually slightly darker than others, palpomere 2 with light patch where sensilla present). Thorax brown to dark brown throughout; scutum setae brown. Coxae nearly the same or lighter in color as thorax, light brown to brown, fore coxa same color as mid- and hind coxa; femora, tibia, and tarsi light brown to brown; hind tibial comb yellowish, preceded by 0-3 (usually 3) dark brown setae. Wing hyaline without markings, wing veins brown; haltere stem and knob cream-colored. Abdominal segments concolorous brown to dark brown. Terminalia brown.

Head. Ocelli slightly raised, median ocellus in line with anterior margin of lateral ocelli, median ocellus approx. 0.4 –0.8× size of lateral ocelli; lateral ocellus located 1.5 –2× diameter of ocellus from eye margin, separated from median ocellus by approx. same distance. Eyes with microsetae, which are approximately as long as width of facet. Frons microtrichose, without setae, flattened. Antennal length 1.5-1.6, 1.5 [1.5] mm (n=3). Face clearly longer than wide, setose; clypeus and labrum microtrichose, without setae. Palpus with four palpomeres; palpomere 1 oblong-triangular, without setae; other palpomeres with golden brown setae; palpomere 2 bearing small pocket of sensilla; palpomere 1 length longer than or subequal in length to palpomere 2; palpomere 3 length subequal to or slightly shorter than combined length of palpomeres 1 and 2; palpomere 4 length 0.7 –1.2× combined lengths of palpomeres 1-3 In female, palpomere 4 appx. length of palpomeres 2-3.

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. Costal wing vein extends beyond R5, approx. two-thirds distance between R5 and M1; R1 approximately the same length as r-m or slightly longer; cubital fork below, slightly proximad or slightly distad of r-m base; R1, M1, M2, CuA1, and CuA2 with setae on upper surface (lacking setae on M1 + M2). Wing veins A1 and CuP absent.

Male genitalia (Figs 73-81). Epandrium dorsal surface with medial depression, where setae are lacking; posterior margin broadly emarginate at center (Figs 74, 75). Posterior processes of epandrium broad, approx. 2.5 × longer than narrowest width, narrowly separated at base, length of setae at base of epandrial processes approximately 0.5 × width of process, bare along most of length (Figs 73, 74). Gonocoxites as in Figs 76-78. Aedeagal fork bifurcated into two tines one clearly longer (approx. 3 ×) and wider (approx. 2 ×) than the other; smaller tine pointed upward, longer tine s-curved, slightly recurved backward at apex (Figs 79-81).

Female. Body length: 3.2 mm (n=1). Wing length: 3.0 mm (n=1). Antennal length 1.1 mm (n=1).

Coloration (Fig. 72). Same as male, except abdominal segments 8-10 brown; cerci light brown to brown.

Head and thorax. Same as male, except antenna length shorter.


The species epithet “radiata” is a noun in apposition, due to the proximity of this species to Pinus radiata  (Monterey Pine). The only known locality for this Megophthalmidia  species, Kenneth S. Norris Rancho Marino Reserve (University of California Natural Reserve System), is one of only three areas where natural Pinus radiata  forests still exist.