Macrostomus alpinus, Rafael, José Albertino & Cumming, Jeffrey M., 2006

Rafael, José Albertino & Cumming, Jeffrey M., 2006, New species of Macrostomus Wiedemann (Diptera, Empididae) from Colombia, Ecuador and Peru, Zootaxa 1136, pp. 49-64 : 50-52

Macrostomus alpinus , n. sp.

( Figs. 1–4 , 40 )

Diagnosis. One pair of ocellar setae; hind femur bicolored, banded with yellow and black, median part and apex black; male fore tarsomeres 1–4 black, not white distally; hind tarsomere 1 with strong anterior and anteroventral setae; cell dm rather acute; M1, M2 and A1 veins rather distinct.

Description. Male. Frons one­third of anterior ocellus width. Face slightly narrower than anterior ocellus width. 1 pair of ocellar seta. Antennae lost in both specimens examined. Thorax black, gray­brown pruinose; 3 dorsocentral setae, the posterior longer; 3 notopleural setae; 4 antepronotal setae; 2 proepisternal setae with one strong; 7–8 katatergital setae. Legs, predominantly yellow with apex of fore tibia, apex of mid femur, distal half of mid tibia, median part and apex of hind femur, entire hind tibia and all tarsi, black; fore tarsomeres 1–4 black, not white distally. Slightly stronger setae: fore tibia with 2 posterior along basal half; mid femur with 1 anterior near apex; mid tibia with 1 anterodorsal near base, 2 posterodorsal at base and apex of median third, 1 posterior near middle, 2 anteroventral along distal half; hindleg longer setation as depicted in Fig. 1 : femur with 2 anterior, one at basal quarter and one at distal quarter; 2 anteroventral, one near middle and one at base of distal third; 1 dorsal at base of distal third. Slender setae: hind tibia with 6–7 dorsal; hind tarsomere 1 with 2 dorsal, 1 anterior and 1 anteroventral, the last rather strong spiniform setae. Wing brown­infuscated at pterostigma and slightly infuscated at costal cell and apex of cell r2+3; cell dm rather acute; M1, M2 and A1 rather distinct; costal margin with longer slender setae at base. Halter whitish. Abdomen black. Terminalia ( Figs. 2–4 ). Tergite 8 ( Fig. 2 ) with small rounded projection distally and a narrow basal cleft. Epandrium ( Fig. 3 ) with anterodorsal and posterodorsal lobes of subequal height, with a small protuberance between them. Anterior cercus short and narrow presenting two parts, the anterior wider with a internal dorsal sinus and the posterior smaller, thinner connected with anterior part ventrally; posterior cercus very large, rounded with many short setae, antero­ventrally with wide protuberance with many yellow marginal setae; anterodorsal lobe slightly sclerotized with few small setae at apex. Hypandrium ( Fig. 4 ) with many long setae, basal pair longer; with small subapical lateral protuberance with short setae.

Size. Body approximately 4.0 mm, abdomen curved; wing length 4.3 mm.

Female. Unknown.

Geographical distribution. Colombia, Ecuador ( Fig. 40 ).

Material. Holotype ɗ: COLOMBIA, Cauca, 11 mi [les] N[orth] Popayan, 1830 m, III.5.1955 (sic), E.I. Schlinger & E.S. Ross coll. (CAS). Paratypes. ECUADOR, Napo­ Pastaza, 6–8 mi [les]. W. Mera, 1500 m, II.10.1955, E.I. Schlinger & E.S. Ross (1ɗ INPA).

Holotype condition. Not dissected.

Etymology. From Latin alpinus = high mountains, in reference to the high altitude in which the specimens were collected.

Discussion. M. alpinus apparently belongs to the same group as M. ciliaticosta , M. lineatus and M. tarsalis . These species all have a rather membranous area medially on the hypandrium. M. alpinus is distinct in having tergite 8 with a small rounded projection, and in having the hypandrium with longer setae concentrated medially along the posterior margin and laterally bearing a small subapical protuberance with short setae.

Figures

FIGURE 40. Distributions of new species of Macrostomus. Symbols represent the known collection localities as follows: square = M. alpinus; diamond = M. ciliaticosta; circle = M. lineatus; star = M. occidentalis; triangle = M. penai; cross = M. tarsalis.

FIGURES 1 – 4. Macrostomus alpinus, n. sp. 1, left hind leg, anterior view, larger setae represented, holotype ɗ; 2, tergite 8, dorsal view, right setae not represented, paratype ɗ; 3, male terminalia, lateral view, paratype ɗ; 4, hypandrium and phallus, lateral view, paratype ɗ. Abbreviations: a ce, anterior cercus; adp, anterodorsal protuberance; ej apod, ejaculatory apodeme; ep, epandrium; hypd, hypandrium; p ce, posterior cercus, pdp, posterodorsal protuberance; ph, phallus; st, sternite; tg, tergite.