Pales Robineau-Desvoidy 1830
Creators: name: Cerretti, Pierfilippo
Publisher: name: Zenodo
Year: 2005
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Tachinidae
Pales

description: Pales Robineau­Desvoidy, 1830 (Figs 1–6, 9–30)
Pales Robineau­Desvoidy, 1830: 154. Type species: Pales florea Robineau­Desvoidy, 1830 (= Tachina pavida Meigen, 1824), designated by Coquillett (1910: 582).
Ctenophorocera Brauer & Bergenstamm, 1891: 38 (also 1892: 342). Type species: Ctenophorocera blepharipa Brauer & Bergenstamm, 1891, designated by Sharp (1893: 299).
Cerosomyia Hutton, 1901: 57. Type species: Cerosomyia usitata Hutton, 1901, by monotypy.
Neopales Coquillett, 1910: 575. Replacement name for Pales Robineau­Desvoidy, 1830 nec Pales Meigen, 1800 [suppressed name] (ICZN 1963).
Macrozenillia Townsend, 1927: 68. Type species: Macrozenillia aurescens Townsend, 1927, by original designation.
Micropales Villeneuve, 1927: 121. Type species: Micropales seminitida Villeneuve, 1927, by monotypy.
Myiofijia Baranov, 1934: 478. Type species: Myiofijia bezziana Baranov, 1934, by original designation.
Paloides Morley, 1944: 170. Replacement name for Pales Robineau­Desvoidy, 1830 nec Pales Meigen, 1800 [suppressed name] (ICZN 1963).
Recognition. Head (Figs 1–4): eye covered with long hairs. Arista with hairs that are shorter than the maximum diameter of the arista; first and second aristomere not longer than wide. Ocellar setae well­developed, proclinate. Medial vertical setae strong, reclinate, sub­parallel. One (rarely 2) reclinate upper orbital seta(e). Two proclinate orbital setae in female, absent in male. Parafacial bare. Face and lower facial margin not visible in lateral view. Vibrissa well­developed, arising near level of lower facial margin. Facial ridge with strong erect setae over most of its length. Genal dilation well­developed, with black setulae only. Palpus sub­cylindrical or sligthly clavate with some setulae ventrally, dorsally and apically. Thorax: Prosternum with some setulae on its lateral margin. Postpronotum with 4–5 setae, the basal 3 arranged in a straight line. Scutum with 3+3 acrostichal, 3+4 dorsocentral, 1+3 intraalar, 2 posthumeral, 1 presutural, 2 notopleural, and 3 supraalar setae (first postsutural supraalar seta longer than notopleural setae), postalar callus with 3 setae. Anatergite bare. Proepisternum bare. Katepisternum with 3 setae. One (rarely 2) robust anepimeral seta(e). Anepimeron with hair­like setulae on posterior half. Anepisternum with 7–10 setae and several long setulae. Katepimeron bare or with at most 3–4 setulae on anterior fourth. Meral setae present. Scutellum with 1 pair of crossed and horizontal apical setae, 1 pair of subapical, 1–2 pairs of lateral and 1 pair of basal setae. Legs: fore coxa with bare medial surface. Preapical anterodorsal seta on fore tibia shorter than preapical dorsal seta. Mid tibia with 2–4 anterodorsal setae, 1 ventral seta. Hind coxa bare or with one or more setae on posterodorsal margin (always bare in the West Palaearctic species); preapical posteroventral seta on hind tibia distinctly shorter than preapical anteroventral seta; hind tibia with 2 dorsal preapical setae. Wing: tegula and basicosta black. Second costal section (CS2) ventrally bare. Base of R4+5 with 3–4 setulae. Section of M between crossveins R­M and DM­Cu longer than section between DM­Cu and bend of M. Bend of M nearly at a right angle or slightly obtuse. Wing cell r4+5 open or closed just at the wing margin. Abdomen (Figs 27–30): oval in shape. Tergites not fused. Ventral edges of tergites 2, 3 and 4 almost entirely overlapping the corresponding sternites. Middorsal depression on abdominal syntergite 1+2 extending posteriorly to the hind margin. Tergites 2 and 3 with one pair of median marginal setae; tergite 4 with a complete row of marginal setae. Median discal setae on tergites 3 and 4 usually present in the West Palaearctic species with the exception of P. latifrons, P. m u r i n a and P. p e re g r i n a. Tergite 5 with a row of marginal and discal setae. Male terminalia (Figs 9, 12–26): hind margin of sternite 5 with a deep cleft; lateral lobe large, with several long setulae; medio­apical margin of lateral lobe with dense microtrichia; transversal membranous stripe present. Tergite 6 divided into two hemitergites. Sternite 6 well­developed and asymmetrical, articulated to segment 7+8 on its left side, and attached to it by a short membrane on its right side. Segment 7+8 usually with some setulae. Epandrium relatively short and convex. Cerci broad, with a dorso­medial suture, apically divided. Surstylus straight, very narrow il lateral view with short and robust setulae latero­distally. Bacilliform sclerite long. Medial plate of hypandrium sub­rectangular in dorsal view; hypandrial arms long, distally sub­parallel, basally joining postero­medially completely encircling the base of the aedeagus. Pregonite hook­like, basally fused to the hypandrium, with some setulae on its posterior margin; postgonite rounded apically and bent anteriorly. Basiphallus without a posterior basal extension. Epiphallus lobe­like. Distiphallus broad, joining basiphallus by a dorsal sclerite and by a ventro­lateral membrane; lateroventral surface of distiphallus sclerotized and covered with scale­like spinules. Female postabdomen and terminalia: Segments 6 and 7 retracted into segment 5. Tergite 6 and 7 interrupted medio­dorsally forming two sub­trapezoidal sclerites bearing setae. Sternites 6 and 7 wider than corresponding tergites. Tergite 8 divided into two curved sclerites. Sternite 8 short and robust, sub­triangular in ventral view. Postgenital plate slightly bent upwards in lateral view, bearing setulae and microtrichia ventrally. Cerci sub­circular in lateral view. Three sub­globular and well sclerotized spermathecae.
Egg: fully embryonated planoconvex microtype (length: 175–255 µm; width: 100–150 µm; height: 80–100 µm). Ovoid­shape with punctuated surface of chorion (cf. Marini & Campadelli 1994).
Remarks. The present definition of Pales excludes P. tamilensis Shima, 1994, which possesses the following non­characteristic features: no ocellar setae, katepisternum with 2 setae, mid tibia with 1 anterodorsal seta, surstylus broad and slightly bent posteriorly, hypandrium not as described above, and distiphallus long and narrow (Shima 1994: 283). It is likely that P. tamilensis should be removed from Pales, but this action is not taken at the present time because the proper placement of this species has not been determined. Pales basitincta (Walker) from Ambon Island, Indonesia, also differs from my concept of Pales in several characters (Shima 1994). There may be other non­Palaearctic Pales that also do not agree in all respects with the definition of the genus adopted here.
Existing keys for the identification of specimens of Palaearctic Pales. Tschorsnig and Herting (1994), Tschorsnig and Richter (1998).
Distribution. Afrotropical, Malgascian, Palaearctic and Oriental Regions, Fiji Islands and New Zealand (Cantrell & Crosskey 1989; Chao 1999; Crosskey 1973, 1976, 1980; Herting 1984; Herting & Dely­Draskovits 1993).
Systematic position of Pales within the Exoristinae. The eggs in Pales, like in all the Goniini (cf. Herting 1960; Wood 1987) are microtype, fully embryonated within a large ovisac and are laid on the leaves of the hosts’ plants; they hatch, after being ingested, in the mesenteron of the host and enter the haemocele by perforating the gut wall (cf. Herting 1960; Rivière 1974). No other morphological features nor combination of characters distinguishes and identifies the Goniini within the Exoristinae (Tschorsnig 1985, Wood 1987); as a consequence, many of the genera known only on male specimens are of uncertain systematic position.
Comparative notes. The genus Pales is morphologically distinguishable from other Palaearctic tachinids in possessing the following features: a) prosternum setose, b) preapical posteroventral seta on hind tibia distinctly shorter than preapical anteroventral seta, c) first postsutural supraalar seta longer than notopleural setae, d) facial ridge with stout and erect setae over most of its length, e) eye covered with long hairs, f) arista thickened on its basal 1/5–1/2, g) apical scutellar setae crossed and horizontal, and usually h) one reclinate upper orbital seta. In the Palaearctic region, P. m a r a e and P. p u m i c a t a include a good percentage (see below) of specimens with two reclinate upper orbital setae; these specimens, when examined superficially, could be mistaken for Clemelis Robineau­Desvoidy, 1863 or some Nilea Robineau­Desvoidy, 1863 and, for a correct identification, require the examination of male terminalia (very different in the three genera) and female genitalia. The goniine genus Clemelis produces microtype eggs like Pales but possesses very distinct features in the male terminalia: the right arm of sternite 6 is very short and attached to segment 7 by a large membrane; the surstylus is wide in lateral view, with relatively long setulae; the pregonite is not fused with the hypandrium and not hook­like. Nilea has macrotype eggs which are laid directly on the cuticle of the host and different male terminalia, and belongs to the Eryciini (cf. Herting 1960, Wood 1987).
The probable sister­group of Pales. The male terminalia of Pales species are very similar to those of Schembria Rondani, 1861: a) surstylus very narrow with short lateroapical setulae (Figs 7–9, 13–18, 20–26); b) hypandrial arms basally joining (not fused), postero­medially completely encircling the base of the aedeagus, showing a hook­like structure in lateral view (Figs 7 a, 9a, 17a); c) pregonite hook­like, basally fused to the hypandrium (Figs 7, 9, 17); d) aedeagus with epiphallus short, lobe­like and very weakly sclerotized. This combination of features are unique within the Tachinidae, so I presume that they are commonly derived and that Pales and Schembria form a monophyletic unit. The sole “remarkable” difference in the male terminalia of Schembria is that the right arm of the 6th sternite is fused with segment 7, a feature also found in the goniine genera Ocytata Gistel, 1848 (Tschorsnig 1985; Cerretti, unpublished) and Prosopodopsis Townsend, 1926 (Cerretti, unpublished); in Pales the 6th sternite is not fused, but attached very closely to segment 7 by a membrane, showing a plesiomorphic state. In external morphology, Schembria is separated from Pales by the following characters: a) mid tibia with 1 anterodorsal seta (at least 2 in Pales), b) wing cell r4+5 with a petiole about 1/7–1/10 as long as the section of M beyond the bend, c) basicosta yellow, and d) the facial ridge with more or less robust, decumbent setae on lower 1/2 or slightly more (in contrast with the robust and erect setae present in Pales). For all these reasons I am of the opinion that Pales and Schembria must, at the present state of knowledge, maintain equal rank within the goniine Pales ­group.
description: Published as part of Cerretti, Pierfilippo, 2005, Revision of the West Palaearctic species of the genus Pales Robineau­Desvoidy (Diptera: Tachinidae), pp. 1-36 in Zootaxa 885 on pages 4-7, DOI: 10.5281/zenodo.170907