Macrostomus occidentalis Rafael & Cumming, 2006, n. sp.
Creators: name: Rafael, José Albertino
name: Cumming, Jeffrey M.
Publisher: name: Zenodo
Year: 2006
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Empididae
Macrostomus
Macrostomus occidentalis

description: Macrostomus occidentalis, n. sp.
(Figs. 20–22, 40)
Diagnosis. Postcranium black dorsally, rather yellow ventrally; thorax, abdomen and legs predominantly yellow; male fore tarsomeres 1–3 light brown, not white distally; hind tarsomere 1 with 7 slender dorsal setae; cell dm rather truncate; M1, M2 and A1 rather evanescent distally; male tergite 8 acute distally with apex rather blunt.
Description. Male. Frons approximately one­third of anterior ocellus width. Face slightly wider than frons only at apex. 1 pair of ocellar setae. Postcranium black dorsally, yellow ventrally. Postgena with slender setae. Antennae black with scape and pedicel yellow; flagellum trisegmented. Palpus yellow. Thorax yellow with yellow to gray­brown pruinescence. 4 dorsocentral setae; 1 presutural supra­alar seta; no postsutural supra­alar seta; 3 notopleural setae; 2 pairs of scutellar setae; 3–5 antepronotal setae; 1–3 tiny proepisternal setae; 3–5 katatergital setae. Legs entirely yellow with apex of hind femur and all tarsi slightly light brown. Slightly stronger setae: hind femur with 5–6 anteroventral subapical stronger. Slender setae: hind trochanter with 1 posterior long and slender; hind tibia with 7 dorsal; hind tarsomere 1 with 7 dorsal. Wing with costal margin and pterostigma inconspicuously light brown­infuscated; cell dm rather truncate; M1, M2 and A1 rather evanescent distally. Halter yellow with knob slightly brown. Abdomen yellow with dorsal half of terminalia black. Terminalia. Tergite 8 (Fig. 20) with rather blunt projection distally. Epandrium (Fig. 21) with anterodorsal and posterodorsal lobes of subequal length. Anterior cercus (Fig. 21) rather elongate; posterior cercus with bifid apex, slender anterodorsal setae and a small inconspicuous simple protuberance at margin. Hypandrium (Fig. 22) membranous at posterior basal half, without strong setae and with a rather membranous paired protuberance distally.
Female. unknown.
Size. Body not measured; wing 3.4 mm.
Geographical distribution. Colombia (Cauca) (Fig. 40).
Material. Holotype ɗ: COLOMBIA [Cauca], Buenaventura, xi.6.1950, Michelbacher and Ross (CAS).
Holotype condition. Left antenna and left mid leg lost. Abdomen in glycerine.
Etymology. From Latin occidens = west, in reference to the distribution, west of the Andes.
Discussion. M. occidentalis appears related to M. ferrugineus (Fabricius) and M. fulvithorax (Curran) which all possess a rather long and truncate tergite 8 projection (although shorter and more acuminate in M. ferrugineus, shorter and truncate in M. fulvithorax). M. occidentalis differs from both in the structure of the male genitalia and in the postcranium, which lacks a dorsal shinning spot (present in the other two species), as well as in hind tarsomere 1, which bears 7 slender dorsal setae (maximum of 5 in the other two species).
description: Published as part of Rafael, José Albertino & Cumming, Jeffrey M., 2006, New species of Macrostomus Wiedemann (Diptera, Empididae) from Colombia, Ecuador and Peru, pp. 49-64 in Zootaxa 1136 on pages 55-58, DOI: 10.5281/zenodo.171981