Two new genera of Swammerdamellini (Diptera, Scatopsidae), with a discussion of the position of the species of Rhexoza
Author
Amorim, Dalton De Souza
text
Zootaxa
2007
1640
41
53
journal article
10.5281/zenodo.179668
e58dcdff-fec7-4f2d-aa2b-8ed80594606a
1175-5326
179668
Pararhexosa
Freeman
(
Figs. 1–3
)
Pararhexosa
Freeman, 1990
: 14
.
Type
–species
.
Scatopse flavipalpis
Edwards, 1928
(orig. des.).
Diagnosis
. A single whorl of setae on flagellomeres, maxillary palpus relatively short, cardo–stipes not fused mesally. Distal end of postmentum not projected between the labella. Pronotal apodeme straight, katepisternum bare along anterior margin. R5 long, in some species an incomplete false r–m vein on M1 or at least an angle on M1. Pretergite 2 present, pretergite 3 absent; sternites 2–6 sclerotized. Male sternite 7 rectangular, without a posterior mesal incision. Aedeagus without lateral projections on which the parameres articulate, no projection distal to aedeagus opening (aedeagal plate) (
Figs. 1–3
).
Discussion
. This genus was described by
Freeman (1990)
including only the
type
–species,
P. flavipalpis
, from
Thailand
.
P. flavipalpis
and some other species presently in
Rhexoza
are clearly plesiomorphic for some of the features modified in other Swammerdamellini genera, as
Coboldia
,
Rhexoza
,
Akorhexoza
,
Quateiella
, and
Abrhexosa
,
e.g.
, the well developed maxillary palpus with a reniform shape, the mesally fused cardo–stipes, the triangular shape of the labellar sclerite, the secondary presence of setae on the proepimeron and on the anterior margin of the katepisternum, the larger spiracular sclerite (i.e., the dorsal part of proepimeron), the presence of meral setae, the unsclerotized anterior abdominal sternites, the male terminalia laterally compressed, and a deep posterior incision in the tergite 9 (
Amorim, 1982
).
Amorim & Haenni (1996)
examined the
holotype
of
Scatopse tubifera
Edwards
, from
Chile
, and concluded that, even though the male was not known, the species was plesiomorphic for these features and should be at least provisorily included in
Pararhexosa
.
Rhexoza chelata
Cook
(
Figs. 1–3
) and
R. senticosa
Cook
, both from
Australia
, were examined in this study and fit in Freeman’s (1990) definition of the genus. They are also plesiomorphic for these features of more advanced Swammerdamellini. These species are herein formally transferred to
Pararhexosa
, which add to the
type
–species and to
P. t u b i f e r a
. Two other undescribed species from
Chile
also fit in the genus. Even though the inclusion of these species in
Pararhexosa
still does not guarantee a monophyletic genus, its placement here is more appropriate than in other genera of the tribe.
Species included
. Oriental:
P. flavipalpis
(
Edwards, 1928
)
. Australian:
P. c h e l a t a
(
Cook, 1971
),
n.comb.
;
P. s e n t i c o s a
(
Cook, 1971
),
n.comb.
Neotropical:
P. tubifera
(
Edwards, 1930
)
;
Pararhexosa
sp. 1 (
Chile
),
Pararhexosa
sp. 2 (
Chile
).