Maietta trimedia Alexander, 1967

(Figs 1b, 2, 4, 5b, 6b, 7b, 8b, 9b, 10b)

Maietta trimedia Alexander, 1967, p. 493 (description); Alexander, 1968 (fig. 19: wing, fig. 20: male terminalia).

Material examined: Holotype. Maietta trimedia Al. Det. C. P. Alexander, male, Chile, Chiloé Is., Chepu [42° 02’ S, 74° 01’ W], 10/ 14-II-1952, Peña, Holotype 9618 (USNM). Part of specimen pinned and part in slide prepared by Charles Paul Alexander. Paratypes. Pinned specimens: Maietta trimedia Al. Det. C. P. Alexander, 1 male and 1 female, Chile, Arauco, Nahuelbuta [37° 46’ S, 72° 59’ W], 5/10/- I-1953, Luis E. Peña (USNM). Allotype. Pinned specimen: Maietta trimedia Al. Det. C. P. Alexander, female, Chile, Chiloé Is., Aucar [42° 10’ S, 73° 30’ W], 15-I- 1952, Luis Peña (USNM). Material identified by Charles Paul Alexander. Pinned specimens: Maietta trimedia Al. Det. C. P. Alexander, 3 male, 3 female and 3 [sex unknown], Chile, Arauco, Nahuelbuta, Butamalal [37° 49’ S, 73° 14’ W], 1100–1400 m, 23/ 31-I-1954, Peña (USNM); Maietta trimedia Al. Det. C. P. Alexander, 5 male and 1 [sex unknown], Chile, Arauco, Nahuelbuta, Pichinahuel [37° 48’ S, 73° 02’ W], 1100–1400 m, 23/ 31-I-1954, Luis Peña (USNM); female, Chile, Chiloé Is., Aucar [42° 10’ S, 73° 30’ W], 6/ 15-I-1952, Peña (USNM). Specimens in slides prepared by Charles Paul Alexander: Maietta squamigera Al. Det. C. P. Alexander, male, Chile, Arauco, Nahuelbuta, Pichinahuel [37° 48’ S, 73° 02’ W], 1100–1400 m, 23/ 31-I-1954, Luis Peña (USNM); Maietta trimedia Al. Det. C. P. Alexander, 1 male and 1 female, Chile, Arauco, Nahuelbuta, Butamalal [37° 49’ S, 73° 14’ W], 1100–1400 m, 23/ 31-I-1954, L. E. Peña (USNM); Maietta trimedia Al. Det. C. P. Alexander, male, Chile, Arauco, Caramavida [37° 40’ S, 73° 20’ W], 1100–1400 m, 23/ 31-I-1954, Peña (USNM); Maietta trimedia Al. Det. C. P. Alexander, female, Chile, Chiloé Is., Aucar [42° 10’ S, 73° 30’ W], 1100–1400 m, 23/ 31-I-1954, Peña (USNM).

Diagnosis. Last flagellomere longer than the penultimate. Dorsal margin of female tergite IX as long as the ventral margin. Parameres divergent. In addition, this species has the largest anepisternum and the smallest laterotergite found in the genus.

Description. Head. Scape 1.7 times longer than wide. Pedicel almost circular, 1.2 times longer than wide. Scape as long as pedicel. Pedicel 2 times longer than first flagellomere. Last flagellomere 1.7 longer than penultimate flagellomere (autapomorphic feature) (Fig. 5b).

Thorax. Thoracic sclerites shown in Fig. 6b. Wing shown in Fig. 7b. Vein Sc ending near the level R 2 branches from R 1. Vein R 2 4 times longer than vein R 2+3. Length of vein R 2+3+4 2.7 times longer than vein R 2+3. First section of vein R 5 1.5 times longer than cross-vein r-m. First section of vein M 1+2 1.9 times longer than cross-vein r-m. Three medial veins present. Vein M 3+4 1.1 times longer than M 4, 2 times the length of cross-vein m-cu. Distance between M 1+2 and R 5 shorter than distance between R 4 and R 5 and distance between M 3 and M 1+2.

Female terminalia. Female tergite X 1.6 times longer than wide. Dorsal margin of tergite X without projections. Cercus straight, 1.9 times shorter than length of tergite X. (A small cercus in this species is homoplastic with the clade 4 in Fig. 11). Ventral margin of tergite IX 1.1 times longer than dorsal margin. Dorsal projection of sternite IX angulated. Hypogynial valves almost circular, 1.1 times wider than long and as wide as sternite IX. Posterior projection of sternite IX stretched out (Fig. 8b).

Male terminalia. Male terminalia illustrated in Fig. 9b (details of chaetotaxy shown in Fig. 10b). Gonocoxite 1.9 times longer than lobe of gonostylus and 1.6 times longer than the clasper of gonostylus. Parameres with pointed lateral margin. Sheath of aedeagus with bifid projection with tips as long as the extremities. Bridge between interbases wider than aedeagus. Long tip of bifid posterior projection of interbases 2.3 times longer than the short tip. Projections of the interbase divergent, i.e. the left interbase pointed to the left and right interbase pointed to the right.

Coloration. General coloration dark brown. Head: dark brown. Rostrum dark brown, palpi dark brown. Antennae obscure yellow with outer segments darker. Thorax: dark brown, pleuron brown. Halters yellowish white. Coxae brown, trochanters obscure yellow, remainder of legs pale. Wings hyaline, scales light brown, veins nearly hyaline. Abdomen dark brown.

Remarks. One specimen of this species was misidentified by C. P. Alexander as M. squamigera Alexander.