Megalinga insignata Irwin & Lyneborg (1981a:244).

Derivation of name: in (Latin) = not; signatus (Latin) = mark.

Diagnosis. Megalinga insignata is readily separated from M. bolbocera in that the males and females have distinctly paler wings with 2 dark brown spots along R2+3, and cell br is hyaline; the halter knobs are pale yellow; the male sternite 8 has a shallow emargination posteriorly, the dorsal apodeme of the aedeagus is nearly three times wider than the ventral apodeme, and the apical cleft of the distiphallus is long and diverges distinctly from the apex of the distiphallus; the female frons are silver to silver brown with two small elongate dark brown areas, the furca is longer in length, and the penis guide is narrow and pointed anteriorly.

Description of holotype male
(CAS Type No. 13670, MEI 005144) Body length 9.0 mm.

Type Material: The holotype Megalinga insignata Irwin and Lyneborg was collected at Bennetts Well, Inyo County, California on 30 March 1952 by A. E. Michelbacher.

Head. Length 1.6 mm. Ocellar tubercle dark reddish brown, dense gray pruinose; ocellar setae black. Eyes dull reddish brown; medial margin sinuate. Frons covered with dense silver pile with a small, elongate, dark brown area dorsolateral on each side of frons. Antenna pale yellow, pale yellow pruinose; style dark brown; setae pale yellow, scattered over scape and pedicel with short brown setae scattered basally on flagellum; macrosetae dark brown, scattered ventrally on scape; length of antenna 0.5 times head length; length of scape 0.18 mm, 1.1 times width, 1.8 times length of pedicel; length of pedicel 0.10 mm, 0.6 times width; length of flagellum 0.36 mm, 2.0 times width, 2.0 times length of scape; length of basal stylomere 0.04 mm, length of apical stylomere 0.08 mm. Parafacial and gena covered with dense silver pile; genal setae white, becoming dark reddish brown near ventral margin of parafacial. Maxillary palpus cylindrical; yellow, yellow pruinose; length 0.46 mm, 3.8 times width; setae pale yellow.

Thorax. Macrosetae: np 3, sa 2, pa 1, dc 2, sc 2. Dark reddish brown, dark yellowish gray pruinose; setae pale gold, appressed. Postpronotal lobe concolorous with thorax; setae pale yellow. Prosternal setae white. Propleuron pale yellow with dense pale yellow pile; anepisternum dark reddish brown with dense gray pile; katepisternum dark reddish brown, its dorsal half dark yellow with dense whitish gray pile, anepimeron dark yellow, dense whitish gray pile, meron reddish brown, dense gray pile; setae pale yellow, abundant on propleuron, scattered over entire anepisternum. Scutellum pale reddish brown, whitish gray pruinose; setae yellow. Laterotergite dark yellowish brown, dense whitish gray pile; setae pale yellow. Wing (Fig. 14). Length 7.2 mm, 2.6 times width; opaque, maculate, particularly at crossveins and forks of veins; R 2+3 with 2 dark brown spots medially; cell br hyaline, without medial dark brown spots; posterior cells hyaline medially; veins pale yellowish brown; pterostigma brown. Halter pale yellow. Legs. Coxae dark yellow, dense yellow pruinose; apical macrosetae brown. Femora reddish brown, whitish gray pruinose; setae white, appressed, lanceolate. Tibiae dark yellow. Tarsomere 1 dark yellow, becoming reddish brown apically; tarsomeres 2-5 reddish brown.

Abdomen. Pale yellowish brown, concolorous, whitish gray pruinose; dorsal and lateral setae white.

Terminalia (Figs. 15-20). Tergite 8 broad, bilobed; posterior margin deeply concave. Sternite 8 moderately reduced, posterior margin with shallow emargination (Fig. 17). Gonocoxite with reduced parameral apodemes. Dorsal apodeme of aedeagus nearly three times wider than ventral apodeme (Fig. 19); apical cleft of the distiphallus long, diverging distinctly from the apex of the distiphallus (Fig. 19).

Variation. Body measurements for males are provided in Table. Variation in the thoracic macrosetal counts was not noticed.

Description of Female

Similar to male with following exceptions. Body measurements for females are provided in Table.

Head. Eyes with medial margin straight. Frons (Fig. 21) dense yellowish gray pruinose, small, linear, brown area dorsolaterally; setae reddish brown, scattered.

Thorax. Macrosetae: np 2-4, 3. Dorsum with scattered reddish brown setae on anterior third in addition to pale gold appressed setae. Legs. Femora dark yellow, yellow pruinose; setae pale yellow, lanceolate, appressed.

Abdomen. Pale reddish brown, yellowish gray pruinose; posterior tergites darker. Terminalia (Figs. 22-24). Tergite 8 and sternite 8 with medial band on elongate, dark brown setae. Furca (Fig. 24) oblong; length 1.1 mm; anterior and posterior margins rounded; lateral margins sinuate; penis guide elongate, pointed anteriorly.

Seasonal Activity. In the specimens examined, adults were taken from 27 March to 30 May, with several specimens collected in a Malaise trap at a water hole.

Distribution. Megalinga insignata in known only from Baja California, southern California, and southwestern Arizona. (Map)

text from Webb & Irwin 1991b

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