Sarcofahrtiopsis thyropterontho, Pape, Thomas, Dechmann, Dina & Vonhof, Maarten J., 2002

Sarcofahrtiopsis thyropterontho View in CoL s Pape, Dechmann & Vonhof, sp. n.

(fi gures 1-6)

Etymology. The species epithet, which should be treated as a noun in apposition, is a word composed from the generic name of the disk-winged bat, Thyroptera , and the Greek noun onthos =dung.

Type material. HOLOTYPE: Costa Rica: Limo'n , Estacio'n Can^o Palma , N of Tortuguero near Cerro Tortuguero , 0-30 m, 10°27'N, 83°32'W, 1-5 June 1999, D. Dechman and M. Vonhof (Instituto Nacional de Biodiversidad). Holotype equipped with a red, handwritten label giving`HOLOTYPE / Sarcofahrtiopsis thyropteronthos / Pape, Dechmann / & Vonhof ’. GoogleMaps Paratypes: 9 8, data as holotype (1 1 in INBio, others in SMNH), and with a yellow, printed label giving`PARATYPE [or] / Sarcofahrtiopsis / thyropteronthos / Pape, Dechmann & Vonhof ’. GoogleMaps

Additional material. Six puparia, three glued together on a piece of cardboard, remaining three loose together in a microvial pinned under the cardboard (SMNH). Description

Male. Head: fronto-orbital plate and postocular strip with yellowish or light golden microtomentum, parafacial plate silvery or at most with weak golden tinge. Parafacial plate with row of widely spaced setae along eye margin (strongest setae at level of lowermost eyemargin); frontal vitta brown to black; frons at narrowest 0.25-0.30x head width (variation may be partly due to shrinkage from preparation method); frontal row of four or fi ve bristles; one reclinate and two proclinate frontoorbital bristles, upper proclinate 0.75x as long as lower; outer vertical bristle well differentiated from the postocular setae, about 0.75x as long as the strong inner vertical seta; gena and postgena grey microtomentose and with black setae, white setae only in posteriormost part and di ffi cult to observe in lateral view; antenna blackish, fi rst fl agellomere 2.5-3.0x as long as pedicel, arista long plumose in basal 0.6; palpus black.

Thorax: dark grey microtomentum with slight yellow tinge. Chaetotaxy: acrostichals =1 (weak)+ 1, dorsocentrals =2+ 3, intra-alars =1+ 1(-2) (anterior weak), supra-alar s =1+ 3, postpronotal s =2, postalars =2, notopleurals =2 (no subprimaries), scutellum with marginal bristles =2 (plus weak secondary bristle near the posterior one), apicals =0, discals =1 (weak, not crossed); meropleurals =4, katepisternals =3 (in a line, middle one weak), prosternum bare, metasternum bare, proepimeron bare, postalar wall bare. Wing hyaline, R setulose in full length to 1 junction with costa, R setulose almost to crossvein r -m, costal spine not differen-4+5 tiated, third costal sector with ventral setae. Legs black; mid tibia with no anterior and anteroventral bristles, two posterior and one posterodorsal bristle; hind tibia with one subapical anteroventral bristle, two anterodorsal and two to three posterodorsal bristles; mid femur with two median anterior bristles, two median anteroventral, two preapical posterior and two (to three) posteroventral bristles, without ctenidium; hind femur with rows of bristles along anterodorsal, anteroventra l and posteroventral margins, and one strong preapical anteroventral bristle; hind coxa bare on posterior surface.

Abdomen: black with the usual pattern of silvery grey microtomentum; T4 and T5 each with a row of marginal bristles.

Terminalia: syntergosternit e 7+ 8, epandrium and cercus blackish brown; syntergosternite 7+ 8 with row of marginal bristles; epandrium with scattered setae of which two to four are bristly. Gonopod slender, gently curved, with most of the curvature taking place along dorsal (posterior) margin; some short setae irregularly spaced along dorsal margin. Paramere with strong bristle just proximal to middle; apodeme at base of paramere not especially elongate. Phallus with cuticular spines laterally on distiphallus; separation between basi- and distiphallus indicated by a change in sclerotization, no hinge-like structure developed. Vesica compact, fi tting into the arched or hood-like juxta, and equipped with a short, uncinnate basal process directed at right angles to the phallic axis. Acrophallus with lateral styli strongly sclerotized and stylar bases visible as slender hooks behind the juxtal wall. Median stylus of medium length and with a few cuticular spines at tip.

Length: 3.0- 3.5 mm.

Female. Like the male in general appearance but with the usual sexual differences. Length: 3.5-4.0 mm.

Puparium. A somewhat slender, barrel-shaped fl esh fl y puparium. Last segment (abdominal segment 8) with a dorsomedian crest [not visible in strict posterior view as it is hidden by the fl aring cavity of the posterior spiracles (fi gure 6), visible in lateral view (fi gure 5)]; cavity of posterior spiracles wide and shallow, taking up entire posterior surface, fl anked by 12 long, triangular processes (fi gures 5, 6). Dorsal processes three to four times longer than reduced ventral ones. Cuticle covered with short pile, slightly increasing in length posteriorly.

Length: 3.5-4.0 mm.

Note. The adult material is teneral due to conservation early after emerging from the puparia and before cuticular sclerotization had been fully completed, and specimens suffer somewhat from shrinking after being mounted from alcohol. Live specimens will probably be slightly longer than indicated.

Distribution. NeotropicalÐCosta Rica,? Panama. It should be noted that Thyroptera tricolor is a lowland species distributed in three subspecies from Veracruz in Mexico through Central America to Rio Juquia in south-east Brazil ( Wilson and Findley, 1977).

Taxonomic discussion

Species of the genus Sarcofahrtiopsis were revised and keyed by Dodge (1965a, 1965b). Mello-Patiu and Pape (2000) describe an additional species and re fi ne the generic de fi nition. The present species is assigned to genus Sarcofahrtiopsis Hall due to agreement with the generic diagnosis given by Mello-Patiu and Pape (2000) in general and due to the possession of a bare metasternal area in particular. Sarcofahrtiopsi s thyropterontho s differs from its congeners in a number of features as follows.

All species of Sarcofahrtiopsis show a long, rod-like elongation of the phallic vesica that is directed towards the base of the phallus, but S. thyropterontho s has a vesical process, which is considerably shorter, and which is perpendicular to the phallic axis. The vesical process is even shorter than that seen in Pacatuba Lopes , which is considered the most probable sister group of Sarcofahrtiopsis ( Lopes, 1990) , and the feature should therefore be considered a specialized (apomorphic) feature of S. thyropterontho s. The third costal sector of S. thyropterontho s is setose ventrally, while all other Sarcofahrtiopsis (and Pacatuba ) have this sector bare. Probably an apomorphic feature as well. Wing vein R of S. thyropterontho s is setose in full 1 length, while all other species of Sarcofahrtiopsis have this row of setae reaching only as far as the level of the subcostal knob. Note that Mello-Patiu and Pape (2000) included the short row of setae on R as a ground-plan feature of 1 Sarcofahrtiopsis . Pacatuba has this vein completely bare, and phylogenetic polarity and ground plan condition cannot be settled in the absence of a species-level cladogram.

The parameral apodeme of S. thyropterontho s is not elongated and differs in this respect from at least S. spathor and S. cuneata (Townsend) . Mello-Patiu and Pape (2000) considered an elongated parameral apodeme as especially valuable in the de fi nition of Sarcofahrtiopsis , and the presence of a short (or normal-sized) parameral apodeme in S. thyropterontho s should therefore indicate a phylogenetically basal position within the genus.

Biology

Flies were successfully bred only from faeces of Spix’s disk-winged bat, and the fl y may be suspected to be partly or entirely specialized to larvipositing in the fresh faeces located in T. tricolor roosts. It is noteworthy that larvae were found in two consecutive years and in almost every roost examined for this purpose (n =259; no exact measure was made on the frequency of larval occurrence, but probably>90% and with no major difference between the two periods). In addition, fl y larvae were observed and collected from a single T. tricolor roost examined on Barro Colorado Island, Panama, March 2000 (conspeci fi city with S. thyropterontho s assumed; no larvae were bred through to adults). Larvae were never found in unoccupied Heliconia leaves, despite extensive searching.

Rearing larvae of Sarcofahrtiopsi s thyropterontho s in the small centrifuge tubes was mostly unsuccessful with only two adults emerging. The second method, using larger containers, was more successful with numerous larvae maturing. Larvae were found crawling in the moistened paper towel (away from the faeces) at the bottom of the containers within 24 h of collection, and puparia were found as early as 48 h after collecting the faeces, also within the layers of the moistened paper towel. All surviving larvae pupated within 72 h. Adult fl ies emerged 8-10 days after larvae were fi rst encountered in the faeces in all cases. No adult specimens of Sarcofahrtiopsis were caught in any of the bait traps.

Bats enter roosts shortly before sunrise (approx. 6 a.m. local time), and larvae were found in roosts as early as 30 min after local sunrise. The tubular leaf-roosts used by T. tricolor (fi gure 7) are only available to the bats for 1 day, and thus the bats must use a different roost-site each day ( Findley and Wilson, 1974; M. Vonhof, personal observation). Leaves were generally fully open after a maximum of 2 days, and any faeces remaining in the leaf fell to the ground, although they left a stain on the surface of the leaf (fi gure 8). Furthermore, roosts occur at low densities (0-11 roosts per ha, mean 2.6), while tubular leaves not used as roosts generally occur at much higher densities (7-89 leaves per ha, mean 40; M. Vonhof, personal observation). Thyroptera roosts do not appear to provide a stable (nor predictable) resource for larviposition, and the female fl y may be constrained to either search a large number of leaves each day to fi nd suitable locations for larviposition, or utilize other breeding media as a more opportunistic coprophage. The almost constant presence of larvae in the ephemeral roosts would then imply either that the fl y is very e ffi cient in its search for roosts, or that it is so common that its mere abundance will ensure breeding in the large majority of roosts. The latter possibility appears to us as unlikely as adults were never observed even though actively searched for in leaves, nor were any adults caught in the traps or attracted to the bait. The early appearance of larvae in the faeces is interesting as adult Sarcophagidae are known to be strictly diurnal and in the humid tropical forests rarely appear on foliage, tree trunks, etc. until well after sunrise (T. Pape, personal observation). The few cases of species of Sarcophagidae caught at light ( Walton, 1915; Audcent, 1951) may be due to local disturbance rather than true nocturnal activity.

Sarcophagid larvae generally develop rapidly, often maturing in 3-5 days under favourable conditions ( Lopes, 1973; T. Pape, personal observation), yet the present indication of a larval feeding period of only (1-) 2 days and pupariation within 72 h may be an adaptation to the short duration of faeces within roosts.

The biology of other Sarcofahrtiopsis spp. has remained largely unknown, but males of S. cuneata (Townsend) are attracted to human faeces and rotting fi sh ( Lopes, 1973; T. Pape, personal observation).