Puyehuemyia chandleri, Amorim & Silva & Brown, 2018

Amorim, Dalton De Souza, Silva, Vera Cristina & Brown, Brian V., 2018, Puyehuemyia chandleri, gen. nov., sp. nov. (Diptera: Opetiidae): remnant of a Cretaceous biota in Chile, American Museum Novitates 2018 (3892), pp. 1-28 : 4-9

publication ID	https://doi.org/ 10.1206/3892.1
DOI	https://doi.org/10.5281/zenodo.5463441
persistent identifier	https://treatment.plazi.org/id/DB43B027-FFF5-FFA1-13FE-6C43F44EF92B
treatment provided by	Carolina
scientific name	Puyehuemyia chandleri
status	sp. nov.

Treatment

Puyehuemyia chandleri View in CoL , new species

Figures 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 , 12A

MATERIAL EXAMINED: Holotype, female, Chile, Osorno , Parque Nacional Puyehue , Termas Aguas Calientes, Sendero Rápido del Chanleufú, Malaise trap, Jan. 14–Feb. 3, 2017, D.S. Amorim and V. C. Silva, cols. ( MNHN).

DIAGNOSIS: As stated for the genus.

FEMALE: Total body length, 2.5 mm (habitus, fig. 1A).

Head (fig. 1B, C): Blackish brown, rounded, eyes reddish, large, dichoptic, dorsal and ventral ommatidia of same size, eye entirely covered with pale ommatrichia. Labella cream yellow; maxillary palpus apparently 1-segmented, small, brownish, apically blunt, no apical sensory pit. Entire frons, occiput, and gena densely covered with setulae. Ocellar triangle clearly defined, ocelli of equal size, well separated. Frons with three well-developed fronto-orbital setae evenly spaced, anterior fronto-orbital and inner vertical slightly lateroclinate, mid and posterior fronto-orbitals inclinate; pair of reclinate strong ocellars, postocellars small. Eyes well separated dorsally at vertex and closely approximated ventrally, frons strongly triangular from a dorsal view. Antenna inserted at dorsal third of head, face slender, setose on ventral third, antennae close together. Antennal scape small, about half length of pedicel, with few setulae along distal margin; scape widening to apex, about one-half length of first flagellomere, with setae around distal half; first flagellomere wider midway to apex, with some scattered small setae on basal half, not produced at junction with arista or stylus; arista clearly with three slender articles of about equal length, texture similar to first flagellomere, covered with microtrichia, lacking setation. Face slender, brown, bare mesally, sparse setae on ventral third of parafacialia. Gena narrow, setose, with some stronger setae in irregular row.

Thorax (fig. 2A, B): Cervical sclerite brown. Scutum dark brown anteriorly, gradually turning ochreous posteriorly; pair of dark brown stripes over undifferentiated dorsocentrals; one strong prescutellar dorsocentrals, no differentiated acrostichals. Two postpronotal setae, one strong and one minute; three strong presutural intraalars in irregular row; two large and three small notopleural setae; one strong supraalar. Scutellum ochreous, with apical pair of stronger, upcurved setae and pair of smaller, anteromarginal scutellars. Thoracic pleural sclerites not strongly sclerotized, ochreous, some areas brown or light brown on prosternum and proepimeron, anteriorly and dorsoposteriorly on anepisternum, on ventral two-thirds of katepisternum, on dorsoanterior corner of meron, on metepisternum and on ventral margin of metepimeron, around posterior spiracle, mesially on mediotergite, and at contact between scutellum and mediotergite laterally (fig. 2A). Pleural sclerites entirely bare of setae, except ventral half of proepisternum. Anterior spiracle small, rounded, surrounded by membrane, placed dorsally to proepimeron. Prosternum V-shaped, bare, more sclerotized ventrally (fig. 2B). Propleural suture sigmoid, proepimeron entirely fused to katepisternum at posterior end. Anapleural suture depressed mesially. Anepisternum cleft dorsal opening bearing single elongated basalare. Short dorsoposterior projection of katepisternum over meron. Katepisternum shield and meron shield well developed (respectively over mid- and hind legs). Meron more or less rectangular, reaching level of posterior spiracle, suture separating meron from mesepimeron and from metepisternum well marked. Partial suture of separation of mesopleurotrochantim and meron present. Limits of laterotergite from mesepimeron anteriorly and from mediotergite posteriorly well marked. Halter elongate, greyish, except lighter area basally; entirely bare of macrotrichia. Metanotum slender, but well characterized.

Legs delicate, coxae dark brown, densely setose anteriorly, remainder of legs brown with light brown areas. Tibial spurs absent on all legs, hind tibia distally with regular comb of longer setae. Tarsomeres gradually shorter, with no denticles or enlarged setae, no teeth on tarsal claws. Foretibia distally with inner, less well-sclerotized area covered with slightly stronger setae, and distal regular comb of elongate setae; mid- and hind tibiae with some more developed setae distally in more or less regular row.

Wing (fig. 2C): Length, 2.5 mm. Membrane light fumose brown, slightly darker along anterior margin, but without maculae. All wing veins bare of macrotrichia except R 1 with setae above along distal three-fourths. Hu present, well developed, Sc complete, reaching C at basal third of wing; R 1 long, gradually approaching C, reaching margin at distal threefourths of wing; R 2+3 long, reaching C close to wing tip, R 5 ending at wing tip (fig. 3A). C clearly circumambient. Transverse vein r-m discrete, in basal fourth of wing; M 1+2 (including sector basal to r-m) slightly longer than medial fork; M 4 thicker and more sclerotized than other posterior veins. Cells bm and br closed, crossvein m-m+M 3 (formerly dm-Cu) absent, very base of M 4 broken, m-cu present, cell cua present, closed, CuA+CuP reaching wing margin (fig. 3B).

Abdominal tergites and sternites light ochreous brown, darker along posterior margin (fig. 3C). No abdominal muscle plaques. Abdomen more or less flattened; segments 1–4 well developed, sternite 1 nearly unsclerotized, posterior border of sternites 2–3 with unsclerotized lunular area, tergites 1–4 sclerotized, with row of slightly more developed setae along posterior margin; segments 5–6 slender, weakly sclerotized, tergite 5 with row of setae along posterior margin, sternite 5 with scattered setae, segment 6 bare, segments 7–8 strongly modified to constitute well sclerotized, elongated ovipositor (fig. 3D). Cercus probably absent.

MALE: Unknown.

ETYMOLOGY: The generic epithet refers to the locality—Puyehue National Park, in southern Chile —where the holotype was collected. Puyehue is the name of one of the big lakes in Osorno Province. The park was created in 1941 just east of the lake. In the Mapudungum, or Mapuche language, hue means “place,” while puye is the common name of the galaxiine fish, Galaxias maculatus (Jenyns, 1842) . The specific epithet honors Peter Chandler, who has a long and substantial contribution to dipterology in general and on platypezids and opetiids in particular, including his excellent review of the European Opetiidae and Platypezidae ( Chandler, 2001) .

DISTRIBUTION: This species is so far known only from the type locality, lowlands of Puyehue National Park. The vegetation is part of the Subantarctic Valdivian phytogeographic district ( Gajardo, 1994), also known as Valdivian Forest. It is dominated by Nothofagus dombeyi Mirb. Oerst. , also having the characteristic Myrtaceae Luma apiculata (DC.) Burret , the conifer Podocarpus nubigenus Lindl. and other austral floral elements.

BIOLOGY: Not much can be said about the biology of this fly. It was collected with a Malaise trap in the lowlands (440 m) of a temperate rain forest, in a patch of primary forest recovering from previous anthropic influence, but still with large Nothofagus trees and a good amount of rotting wood and woodland detritus (fig. 4). The general structure of the environment where P. chandleri was collected is similar to the reports for O. nigra in Europe (e.g., Roháček and Ševčík, 2011; Tkoč and Roháček, 2014) and for the Japanese species of the genus ( Saigusa, 1963). It is interesting to note that O. nigra adults have been reared from rotten Fagus wood ( Speight et al., 1990; Chandler, 2001) and the larvae are still unknown. The sclerotized, piercing ovipositor of the females in Opetia species and in P. chandleri may suggest a parasitoid biology for the larvae, even though some tephritoids have a piercing oviscapt used to oviposit in fruits or stems. If this is correct, it would explain why the larvae have not been found although quite a number of adults have been reared from different localities.

COMMENTS: The spermathecae cannot be observed without dissection. In Opetia there is a single, unpigmented spermatheca ( Sinclair and Cumming, 2006). It may be the case that the spermathecae is similar in P. chandleri . Additional specimens would allow dissection of specimens, clarifying several morphological features, including details of the maxillary palpus and ovipositor. There are some dimorphic features in Opetia that may well apply also to Puyehuemyia . Females of Opetia also have dichoptic eyes, with undifferentiated dorsal and ventral ommatidia, and the anal lobe is not developed in the wing. Male eyes of Opetia nigra (fig. 5A, C) are holoptic, the dorsal ommatidia are larger than the ventral ones, and the wing has a well-developed anal lobe.