Revision of the West Palaearctic species of the genus Pales RobineauDesvoidy (Diptera: Tachinidae)
Author
Cerretti, Pierfilippo
text
Zootaxa
2005
885
1
36
journal article
10.5281/zenodo.170907
6d24a957-c673-4d86-938f-739ddfe6b06c
11755326
170907
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.