Phacelochaeta Norrbom, 2010

Norrbom, Allen L., Sutton, Bruce D., Steck, Gary J. & Monzón, José, 2010, New genera, species and host plant records of Nearctic and Neotropical Tephritidae (Diptera) 2398, Zootaxa 2398, pp. 1-65 : 33-34

Phacelochaeta Norrbom , new genus

Type species: Procecidochares quinquefasciata Hendel, 1914 .

Diagnosis. This genus includes three species from Ecuador, Peru and Bolivia, one of which is here described. Their biology is unknown, but they occur at relatively high elevations (2800–5000 m). The two previously described species have most recently been classified in the genus Cecidochares Bezzi , but do not belong in that genus nor the tribe Cecidocharini (sensu Korneyev 1999) . They have the lateral vertical seta white, lanceolate, and less than half as long as the blackish medial vertical seta, the postocular setae mixed small, acuminate and large, lanceolate, and the frons setulose medially ( Fig. 70) (see discussion under Dracontomyia ).

Probable synapomorphies of Phacelochaeta include: scutellum ( Fig. 70) with 5 marginal clusters of whitish, lanceolate setulae, including one proximal to each basal seta, one on both sides between the basal and apical setae, and an unpaired medial apical cluster between the apical setae (a pair basal to the basal seta occurs in most Stenopa and some Dracontomyia species and in many Cecidocharini , e.g., Hetschkomyia , Neorhagoletis , and a few species of Cecidochares and Procecidochares , but the 3 distal clusters are unique to Phacelochaeta ); subscutellum with ventral half nonmicrotrichose (also occurs in Hetschkomyia and Neorhagoletis ); wing ( Figs. 54–56) with oblique band covering pterostigma and crossveins r-m and dm-cu, r-m displaced distally, distance from bm-cu to r-m along vein M/ distance from bm-cu to dm-cu 0.73–0.76; and surstyli ( Figs. 66–67, 75–76) elongate and posteriorly curved (in Cecidochares species they are relatively short; Fig. 69).

In wing pattern and venation, species of Phacelochaeta superficially resemble Tomoplagia Coquillett , but differ from them by the same characters as above. They may be most closely related to Dracontomyia and Stenopa (see discussion under Dracontomyia ), which they resemble in mesonotal microtrichia and setulae patterns, having a strongly convex scutellum, and banded wings. They differ from species of those two genera in having crossvein r-m distinctly distal to the midlength of cell dm and in the middle of the same oblique band covering the pterostigma and crossvein dm-cu.

Description. Most major setae blackish; most setulae whitish, lanceolate.

Head: Frons broad; setulose medially. 3 black frontal setae; 2 orbital setae, anterior seta black, posterior seta usually white (variable, sometimes black in quinquefasciata ). Ocellar setae well developed, black. Postocellar and postvertical setae white, lanceolate. Postocular setae mixed small brown acuminate and large white lanceolate; lateral vertical seta less than half as long as medial vertical seta, white lanceolate. Arista minutely pubescent. Proboscis capitate, labella large and fleshy.

Thorax: With dark brown to black ground color, mostly densely gray to tan microtrichose; posterior margin of scutum, margin of scutellum (ventral to setae) at least laterally, and at least dorsal half of subscutellum densely dark brown microtrichose; small medial area on anterior margin of scutum, entire disk of scutellum, ventral part of subscutellum, and most of mediotergite shiny, nonmicrotrichose. Mesonotal setulae white, lanceolate; nearly evenly distributed on gray or tan area of scutum; blackish posterior area of scutum nonsetulose except for 4 clusters of setulae near posterior margin. Scutellum strongly convex; nonsetulose except 5 clusters of setulae on margin, 1 pair of clusters basal to basal seta, 1 pair between basal and apical setae, and 1 unpaired cluster between apical setae. Anepisternum, anepimeron, and katepisternum setulose. Postpronotal, 2 notopleural, pre- and postsutural supra-alar, intra-alar, postalar, acrostichal, dorsocentral, 2 scutellar, 1-several anepisternal, 1-several anepimeral, and 1 katepisternal setae present. Pleural setae and setulae whitish except katepisternal seta and most dorsal anepisternal seta. Posterior notopleural seta white. Dorsocentral seta very close to transverse suture. Apical scutellar seta 1/3–1/2 as long as basal scutellar seta.

Legs: Entirely yellow to orange brown.

Wing: Costa with marginal setulae at humeral break not enlarged; at subcostal break with 2–3 larger setae. Pattern with base orange brown and 5 transverse to oblique bands, basal area and subbasal band broadly connected in cells c, bm, and bcu. Third band covering pterostigma and crossveins r-m and dm-cu. Crossvein r-m at 0.71–0.77 distance from bm-cu to dm-cu. Vein R 2+3 nonsetulose dorsally and ventrally; vein R 4+5 dorsally with a few setulae basally and between r-m and dm-cu, ventrally setulose to level of dm-cu, sometimes interrupted. Vein R 2+3 relatively straight, slightly sinuous distal to r-m; moderately long, ending considerably distal to level of dm-cu. Cell r 4+5 more or less parallel-sided, without bulla anterior to dm-cu.

Male terminalia: Surstyli ( Figs. 66–67, 75–76) without posterodorsal lobe, elongate, projecting posteriorly at nearly 90° angle to epandrium; lateral surstylus tapering to very slender, acute apex. Medial surstylus closely associated with lateral surstylus, with pair of stout prensisetae. Glans ( Figs. 68, 77–78) short and stout, mostly sclerotized, acrophallus with subapical bend.

Female terminalia: Oviscape moderately long, shiny nonmicrotrichose, with setulae acuminate to slightly lanceolate. Eversible membrane ( Fig. 72) with paired taenia dorsally and ventrally, denticles simple, decreasing in size posteriorly. Aculeus ( Figs. 73–74) relatively narrow, gradually tapering to slightly elongate, blunt apex.

Etymology. The name of this genus is derived from the Greek phakelos (cluster, bundle) and chaite (hair), in reference to the clusters of lanceolate, white setulae on the posterior margin of the scutum and scutellum. It is considered feminine in gender.