Leucophora plumiseta (Malloch, 1934)

Figs. 38–40

Hammomyia plumiseta Malloch, 1934:194 . Type locality: Peru, Lima, Verrugas Canyon; Albuquerque, 1953:538 (catalogue); Pont, 1974:7 (catalogue).

Diagnosis. Leucophora plumiseta can be differentiated from its congeners by the following combination of characters: arista plumose, 9–10 pairs of fr s, with three longitudinal vittae on thorax; male with vibrissal angle projected beyond the frontal angle in profile, the central vitta on thorax extending only over dorsal surface of the scutellum, not over the ventral surface of the scutellum nor over the mediotergite.

Material examined. Holotype 1 ♂ (BMNH): Peru, Lima, Verrugas Canyon https://data.nhm.ac.uk/object/ 5c167137-56ed-470b-b62a-ca0cabd1ab52

Other material: 1 ♀ (IFML). ARGENTINA: Tucumán, Burruyacú, V . Padre Monti [-26.4998, -64.7412] [529 m. a.s.l.] 17-I–7-II-1948. R. Goldbach col. Det. F. Snyder, 1 ♀ (DIP0894) .

Description

Male (Fig. 38)

Body length 6.6 mm, wing length 5.8 mm.

Coloration (Fig. 38). Head black to dark brown, with light greyish pruinosity; frontal vitta dark brown to black (Fig. 38B). Fronto-orbital plate, parafacialia and genae with whitish-silvery pruinosity; parafacialia in profile with a wide shifting dark brown to black patch from level of insertion of antennae to mid-length of postpedicel (Fig. 38C); genae with a brown patch from vibrissal angle to almost the lower eye margin. Face with light brown pruinosity. Ocellar triangle with dark brown pruinosity. Antennae dark brown to black; pedicel lighter on distal margin; arista light brown with dark brown base. Prementum dark brown. Palpi brown with darker apices. Thorax black to dark brown, with grey pruinosity; with three longitudinal dark brown vittae (Fig. 38D), central vitta anteriorly filling the space almost between the acrostichal setae, at middle almost reaching the dorsocentral setae, extending on the scutellum, lateral vittae filling the space between the posthumeral and supra-alar presutural setae and intralar postsutural and prealar and supra-alar setae.Anepisternum with some light brown patches. Legs brown. Fore femora and dorsal surface of mid and hind femur darkened. Fore and mid tibiae slightly darkened, hind tibiae lighter. Tarsomere dark brown. Pulvilli brown. Wing membrane hyaline. Veins brown. Calypters whitish. Halteres brown with darker base. Abdomen dark brown with greyish pruinosity, with a continued longitudinal dark brown vitta (Fig. 38D), with a dark brown band at posterior margin of each segment (Fig. 38A).

Head. Fronto-orbital plate at narrowest point 0.8x width of anterior ocellus, widening anteriorly; frontal vitta at narrowest point 1.2x width of anterior ocellus, slightly widening towards lunule; eyes separated at narrowest point 3.0x width of anterior ocellus (Fig. 38B). 9–10 pairs of fr s; with short setulae in between (Fig. 38C). infr s as long as the shortest fr s. oc s the longest setae on head; ocellar triangle with 3 additional pairs of setulae; poc s slightly shorter than the oc s. i vt s slightly shorter than oc s, convergent; o vt s about 0.5x the length the i vt s. Postpedicel 2.0x the pedicel length; arista 2x the postpedicel length, plumose, longest hairs 1.5x the postpedicel width. Parafacials 0.5x width of eye. Genae below lowest point of eye margin 0.25x eye height. Vibrissal angle in profile projected beyond frontal angle (Fig. 38C). Prementum 0.7x head height. Palpus slightly expanded at tip.

Thorax. Chaetotaxy: 5 pairs of psut acr s, prescutelar pair longer than the longest presut acr s (Fig. 38D). Prealar seta less than 0.5x the length the notopleural anterior. 6 anepst s. 2+2 kepst s, lower anterior less developed.

Abdomen. Lateral marginal setae strong (Fig. 38D).

Female (Figs. 39–40)

Body length 6.6 mm, wing length 5.7 mm.

Differs from male as follows:

Coloration (Fig. 39). Head with frontal vitta dark brown, lighter anteriorly (Fig. 39B). Fronto-orbital plate with brown-golden pruinosity on posterior half, otherwise silvery. Parafacialia and genae white-silvery pruinosity; patches on parafacialia and genae slightly lighter (Fig. 39C). Ocellar triangle with brownish pruinosity. Thorax. Black to dark brown, with brownish-grey pruinosity; with three longitudinal dark brown vittae (Fig. 39D), central vitta filling the space between almost between the dorsocentral setae, slightly extending on anterior half of scutellum (Fig. 39A). Abdomen. Dark brown with greyish pruinosity, with a longitudinal dark brown vitta (Fig. 39D), interrupted at anterior margin and connected with a dark brown band at posterior margin of each segment; in profile with an expansion of the dark brown posterior margin band in tergites 3–4 (Fig. 39A). Major setae with darker base.

Head. Fronto-orbital plate at narrowest point 2.0x width of anterior ocellus, widening anteriorly, with minute scattered setulae; frontal vitta at narrowest point 2.3x width of anterior ocellus, almost parallel sided; eyes separated at narrowest point 6.0x width of anterior ocellus (Fig. 39B). 9 pairs of fr s setae, with short setulae in between (Fig. 39C). infr s short and thin. oc s as long as the longest fr s; ocellar triangle with 2 additional pairs of setulae; poc s slightly shorter than oc s. o vt s as long as the longest fr s. Postpedicel 1.6x the pedicel length; arista 1.7x the postpedicel length, plumose, longest hairs 1.1x the postpedicel width. Parafacials 0.25x width of eye. Genae below lowest point of eye margin 0.3x eye height. Vibrissal angle in profile reaching the frontal angle (Fig. 39C). Palpus filiform.

Thorax. Chaetotaxy: prescutelar pair longer than the longest psut acr s (Fig. 39D). Prealar seta 0.5x the length the notopleural anterior seta. 5 anepst s. 1+1 kepst s (Fig. 39A).

Legs. Mid femur with 1 av seta on basal fourth; 2–3 pv setae on basal third; a row of a setae slightly projecting beyond basal half; 2 p setae. Mid tibia with 1 ad and pd setae; 2 p setae. Hind femur with a complete row of av and ad setae; 2 subapical d setae; 1 subapical p and pv setae. Hind tibia with 3 av setae; 2–3 ad and pd setae.

Abdomen. Lateral marginal setae strong (Figs. 39A, D). Sternite 1 more than 2x wider than long, with a couple of setulae on posterolateral corners. Sternite 2 2x longer than wide, narrowed posteriorly. Sternites 3–5 almost 1.5x longer than wide, narrowed towards anterior margin; sternites setulose, longer pair of setae on posterolateral margin; sternite 5 with abundant long setulae.

Ovipositor (Fig. 40). Tergite 6 represented by a pair of plates almost narrowly separated on posterior half, wider than long, widened towards lateral margins, less pigmented towards inner basal margins (Fig. 40A); posterior margin with two rows of abundant setae, the anterior row with longer setae (longest setae longer than tergite length), rows extending onto lateroventral membranes forming with the setulae of sternite 6 a more or less continuous band around segment. Spiracles 6th and 7th both situated in membrane (Fig. 40B), 6th at posterior half, 7th on posterior margin in line with the rows of setae. Tergite 7 represented by two lateral plates widely separated, longer than wide, longer than tergite 6, with anterolateral corner acute and incurved; on posterior margin with two rows of setae extending onto lateroventral membranes connecting with the setulae of sternite 7 (longest setae shorter than tergite length), the dorsal space between both plates bare. Tergite 8 widely divided into a pair of strongly sclerotized and pigmented lateral plates continuous along a broad posterior margin and almost connected each other preapically, the longest tergite; in dorsal view, tapered anteriorly, with rounded apex; in profile (Fig. 40C) rather wide posteriorly and tapered anteriorly; posterior margin with two rows of short and strong setulae. When fully extended, anterior tip of tergite 8 remains partially hidden in the anterior segment (Figs. 40A, C). Epiproct laterally fused with cerci, almost 2x wider than long, notched on posterior margin with two pairs of setulae. Sternite 6 1.1x wider than long (Fig. 40B), as long as tergite 6, with anterior margin rounded and well-sclerotized; posterior margin slightly concave and less-sclerotized; posterior margin with many rows of setulae. Sternite 7 more than 1.5x longer than wide, slightly shorter than tergite 7 and longer than sternite 6, anterior margin tapered and well sclerotized, posterior margin less sclerotized, with many rows of short setulae. Sternite 8 represented by a pair of small and scarcely sclerotized plates, setulose. Hypoproct wider than long, with posterior margin rounded, pilose and setulose, longer setulae on posterior margin. Cerci broad distally, as long as epiproct (Fig. 40A), in profile parallel sided; dorsally on distal half with recurved spines with acute apex, two longest and stoutest towards inner margin (longer than cerci height) (Fig. 40C). Spermathecae (Fig. 40D).

Remarks. The male specimen could only be examined through photographs of type material. In external appearance, the male of L. plumiseta resembles those males of L. calilegua sp. nov., L. chalten sp. nov., and L. junin sp. nov., but can be differentiated from L. calilegua sp. nov., by the vibrissal angle projected beyond the level of the frontal angle in profile, and by 9–10 pairs of fr s; from L. chalten sp. nov., by the plumose arista; and differs from L. junin sp. nov., by the absence of the longitudinal vitta on the ventral surface of the scutellum and mediotergite. The ovipositor structure in L. plumiseta is similar to L. johnsoni, but differs in the shape of tergites 6–8.

Distribution. Neotropical: ARGENTINA * (Tucumán), PERU (Fig. 56C).