Pseudeurybata zeta, Marshall, S. A., 2016

Marshall, S. A., 2016, Revision of the genus Pseudeurybata Hennig (Diptera, Micropezidae, Taeniapterinae), Zootaxa 4132 (2), pp. 254-268 : 266-267

Pseudeurybata zeta new species

Figs. 45–52

Description. 13–14mm. Epicephalon shining but head otherwise pollinose. Frontal vitta broad anteriorly, barely distinguishable from narrow orbital strips, postocellar part of vitta slightly narrowed behind ocelli but almost parallel-sided. Postocellar seta absent (in contrast to congeners). One lower fronto-orbital seta. Base of arista yellow and slightly swollen; arista bare. Clypeus densely microsetulose.

Thorax mostly reddish brown, notum darker than pleuron and with a broad silvery median longitudinal strip, postpronotal lobe and notopleuron silvery except for a brown area around posterior notopleural seta. Postpronotal lobe with anterior margin swollen, with a tuft of setae. Anepisternum and anterior part of katepisternum bare except for white microsetulae.

Legs brown except for hind tarsomere one, which is white on basal 3/4. Wing infuscated, slightly darker along leading edge; halter knob brown.

Female abdomen with pleuron colour as described below for male; oviscape uniformly brown, setulose basally, shining and tapered disally, 3X length of T6. Spermathecal ducts conspicuously hirsute, paired spermathecae elongate and distally expanded, smooth, stems long and sinuate up until expanded spermathecal base, without processes; single spermatheca elongate and small. Ventral receptacle long and narrow, far from point of origin of separate spermathecal ducts (distal part of bursa copulatrix forming a broad common spermathecal duct).

Male (one specimen). Pleuron 2 with a large pleural sac extending length of segment, dark on dorsal third, cream yellow on ventral third. Pleura 3–5 dark on dorsal third, not inflated like pleuron 2. Genital fork large, with long arms encircling an elongate-oval space, inner surface with 9 short stout spurs and a broad basal tubercle with 3–4 stout spurs. Epandrium sparsely setose except posteroventral corner where it is densely short-setose. Basal part of basiphallus very broad and heavily sclerotized, phallic bulb large and heavily sclerotized dorsally, ventrally continuous with short, sinuate distal distiphallus section.

Type material. Holotype (♀, USNM). ECUADOR. Napo. Res. Ethnica Waorani, 1kmS Onkone Gare Camp, TransEnt 4.Oct. 1994, 220m, 039 ° 10' S 076 ° 26, W, T.L. Erwin et al, Insecticidal fogging of mostly bare green leaves, some with covering of lichens or bryophytic plants in terra firme forest [= upland forest]. At trans 2 Stn. 7 Project Maxus lot 866.

Paratypes. ECUADOR, Napo. Res. Ethnica Waorani, 1kmS Onkone Gare Camp, TransEnt 7.Oct. 1994, 220m, 039 ° 10'S 076 ° 26'W, T.L. Erwin et al, Insecticidal fogging of mostly bare green leaves, some with covering of lichens or bryophytic plants in terra firme forest [= upland forest]. Trans. 7 Sta. 4. Project Maxus lot 893 (1♂, USNM). COLOMBIA. Amazonas. Amacayacu National Park, Sector Matamata, 150m, Malaise trap, 11– 24.April.2000, debu00138387, A. Felix (1♀, IAVH). One damaged specimen (sex unknown, no abdomen, only 2 legs) from the latter locality was used for sequencing but was not labelled as a paratype.

Non-type material examined. Two BMNH specimens labelled " Brazil. Amazonas, H. W. Bates" and identified as Phaeopterina heteropus Frey , are almost certainly this species, a conclusion based on photographs (taken in 2014) clearly showing the chaetotaxy and pruinosity pattern of the scutum. I would be reluctant to dissect a specimen collected by Henry Walter Bates, and prefer not to designate these specimens as types without dissection.

Etymology. The specific name of Pseudeurybata zeta is an arbitrary collection of letters. A name beginning with "z" was chosen because this species is added on to the end of this revision as an outlier.

Distribution. Ecuador, Colombia, Brazil.

Remarks. Pseudeurybata zeta , the only South American member of the genus, differs widely from other members of the genus in head chaetotaxy and in structure of the male and female genitalia, but resembles other Pseudeurybata in pleural pigmentation, size and colour. More significantly, this species keys out to Pseudeurybata on the basis of its receeding clypeus. The pattern of marginal silver pruinosity, anteriorly tufted postpronotum and uniquely hirsute spermathecal ducts render P. zeta a distinctive species. Described species in the closely related genus Phaeopterina (sometimes treated as a subgenus of Scipopus ) also lack postocellar bristles, so the placement of P. zeta should be reconsidered when that genus is fully revised.

Figures

FIGURES 45 – 52. Pseudeurybata zeta. 45, male, head and notum, dorsal view; 46, male paratype, habitus lateral; 47, male abdomen, ventral view; 48, male abdomen, lateral view; 49, male terminalia, lateral view; 50, female head, lateral view; 51, female holotype, habitus lateral; 52, spermathecae and associated structures.