Ptilosphen yasuni Marshall sp. nov.
urn:lsid:zoobank.org:act: 9A0A3494-FDEE-445E-AF5F-CF686F133C0F
Fig. 27
Etymology
The name is a noun in apposition taken from the type locality.
Type material
Holotype
ECUADOR • ♂; Prov. Orellano, Yasuni Natl. Pk., Yasuni Research Station; 0°40′S, 76°24′W; 250 m a.s.l.; 25 Apr.–8 May 2009; S.A. Marshall leg.; CO 1 specimen MYCRO945-22; QCAZ.
Paratypes
COLOMBIA • 1 ♀, 1 ♂; Putumayo, Parque Nacionales Naturales La Paya Caban Viviano Varzea; 320 m a.s.l.; 15–20 Oct. 2011; R. Cobete leg.; Malaise; IAVH.
ECUADOR • 1 ♀, 4 ♂♂; same data as for holotype; CO 1 specimen MYCRO945-22; QCAZ • 4 ♂♂; same data as for holotype; DEBU • 3 ♀♀, 4 ♂♂; same data as for holotype; V. Belluz and C. McCreary leg.; DEBU • 1 ♀; same data as for preceding; 14–19 Feb. 1998; D.C. Darling leg.; DEBU • 3 ♀♀; Prov. Orellano, Tiputini Biodiversity Station; Aug. 1999; M. Kotrba leg.; USNM • 1 ♀; same data as for preceding; W.N. Mathis, A. Baptista and M. Kotrba leg.; USNM • 1 ♀; Yasuni Ntl. Pk, Yasuni Research Station; 0°38′ S, 76°36′ W; Nov. 1998; T. Pape and B. Viklund leg.; Malaise trap, rain forest; DEBU ..
Other material examined
COLOMBIA • 1 ♀; Prov. Putumayo, La Paya Fca, Charapa; 0°8′ S, 74°57′ W; 330 m a.s.l.; Oct. 2001; R. Cobete leg.; IAVH • 1 ♀; Prov. Caqueta, Serrania de Chiribiquete Rio Cunaré, bos. Tierra; 0°32′ N, 72°38′ W; 330 m a.s.l.; Nov. 2000; Gonzalez and Ospina leg.; IAVH.
ECUADOR • 4 ♂♂; same data as for holotype, excluded from paratype series because they have an apparently atypical pale pleural sac; DEBU.
VENEZUELA • 1 ♀; Bolivar. Rio Grande Research Station, 26 km E of Palmar; 700 m a.s.l.; 24–25 Mar. 1978; J.B. Heppner leg.; rainforest; USNM.
Description
LENGTH. 13–15 mm.
COLOUR (Fig. 27A, D–E, G). Pale orange except as follows: preocellar frontal vitta mostly velvety black to dark reddish brown but orange at anterior margin; postocellar frontal vitta and adjacent epicephalon densely silvery pruinose but sometimes with a narrow bare and shiny area immediately behind ocelli; frontal plate shiny brown with distinct longitudinal striae; paracephalon shiny brown. Lunule orange; face sometimes with a black patch anteromedially; clypeus densely pale microtrichose, yellow. Antenna and subantennal depression black; subantennal depression bare, shiny. Palpus yellow to pale orange. Thorax orange, posterior margin of anepisternum with a silvery pruinose patch. Fore tarsus white; fore femur orange on basal half, dark brown distally, fore tibia brown. Mid tarsus and tibia dark brown; mid femur with a pale base, otherwise uniformly orange or with an indistinct medial pale ring; hind femur with a pale subbasal area 2–3× femoral width and a weak medial pale ring subequal to femoral width; margins of rings not distinct or darkened; hind tibia and tarsus dark brown. Wing with discal band small and subquadrate, extending from R4+5 to CuA1; apex of wing indistinctly pigmented. Male abdomen with T1 orange; T2–6 black to brown sometimes with weak central orange strip, T7 orange-brown; T5 entirely microsetulose, T3 silvery microsetulose laterally but almost bare centrally from anterior to posterior margin, T4 microsetulose but weakly so dorsally and epandrium dark. Pleural pigmentation distinct: female with P1 pale reddish brown, P2 with a broad diagonal dark brown strip slightly tapering ventrally, P3 with a brown dorsal third, and upper part of P4–5 with dark area increasing in extent towards posterior margin. Abdominal pleuron of male with a densely microsetulose elongate oval pleural sac occupying most of P2 and dark band of P3 encircling posterior margin of segment; pleural sac usually dark and longer than high (as in type specimen) but pale and higher than long in some specimens (two such specimens were dissected and matched the type in other features). Oviscape with a broad preapical black ring and an orange apex, heavily silvery pollinose dorsally and basally, orange laterally.
HEAD. Frontal vitta convex, 0.6× as wide as frons at maximum, sharply tapered to anterior margin and gently tapered to a broadly rounded posterior margin. Two fronto-orbital bristles, a large upper (orbital) at level of upper ocelli and a small lower (frontal). Frontal plate with about six distinct striae, orbital plate smooth and mostly shiny but upper epicephalon microsetulose from inner vertical to posterior vitta. Outer vertical bristle present.
THORAX. Prosternum microsetulose and with scattered fine setulae anteriorly. Cervical sclerite of female with a slightly concave middle part and a strongly lobate posterior quarter; male cervical sclerite only slightly convex on posterior half. Scapular setae absent. Katepisternum with one main posterior row of strong yellow bristles, setae anterior to row fine and pale.
FEMALE TERMINALIA (Fig. 27H). Single and paired spermathecae similar in size and shape, elongate oval with an evaginated apex in available dissections; primary (paired) duct parallel-sided, twice as wide and 1.5× as long as single duct, ending in a small bulb separated from the long, sinuate paired spermathecal stems by a thin, threadlike constriction about as long as duct width. Single spermathecal duct without an apical bulb, apically separated from the very short-stemmed spermatheca by a remarkably long threadlike constriction as long as the spermatheca and its short stem. Spermathecal ducts arising together at apex of narrow bursa extension.
MALE TERMINALIA (Fig. 27B–C, F). Genital fork arm mostly cylindrical but incurved to a slightly swollen apex, with short, stout spines on inner surface most densely packed at base and apex; base of fork between arms about twice as long as arms, with a median groove and a deep narrow cleft. Postgonite broad, larger than basiphallus and distinctly longer than in congeners, with strongly spinulose posterodistal surface. Basiphallus smaller than base of distiphallus, barely projecting posteriorly as a rounded lobe (Fig. 27F). Distiphallus longer than epandrium, distal distiphallus almost straight, with distinct transverse striations or rings, 0.3× as wide and 1.3× as long as basal distiphallus, apex forming a broad funnel. Phallic bulb elongate, appearing mostly as a simple swelling between basal and distal distiphallus, distal chamber small and cap like. Hypandrium with tongue-like anterior bridge. Ejaculatory apodeme slightly smaller than epandrium.
Remarks
Ptilosphen yasuni Marshall sp. nov. belongs to the Pt. insignis species group, members of which can be difficult to distinguish on the basis of external morphology. It resembles Pt. notatus Marshall sp. nov. in having a long distal distiphallus and strongly incurved genital fork arms, but the spermathecal complex differs conspicuously between these species. The maximum likelihood analysis (Fig. 30) shows Pt. yasuni next to a clade including Pt. insignis and Pt. crassus Marshall sp. nov.
Publication Date: 2026-05-26