A review of Anapausis Enderlein (Diptera: Scatopsidae) in the Neotropical Region, with four new species and comments on the phylogeny of the genus
Author
Amorim, Dalton De Souza
Author
Balbi, Maria Isabel P. A.
text
Zootaxa
2006
1300
1
29
journal article
10.5281/zenodo.173627
bc7c4215-6044-4a9e-8c41-ba797ada1f07
11755326
173627
Anapausis
Enderlein, 1912
Anapausis
Enderlein, 1912
: 278
–279. Typespecies:
Scatopse soluta
Loew
, by original designation
Diagnosis.
Flagellum with 8, exceptionally 7 flagellomeres. Dorsal half of proepimeron bearing spiracle, “spiracular sclerite” incompletely separated from ventral part of sclerite; M1 incomplete basally, R5 moderately long, strongly bent toward C; wing membrane with setae and microtrichia; pedicel of halter with single seta or bare. Genital vesica attached to male terminalia, distal tubular aedeagus present. Female T10 not divided.
Comments.
Comments and corrections must be made on Cook’s (1965) characterization of the genus. First, the homology of R5, understood by him as R3, is not correct. The reduction in the length of R
5 in
Anapausis
is apomorphic in relation to the condition seen in the Psectrosciarini.
Cook (1965)
also stated that the spiracle is on a separate sclerite. The “spiracular sclerite”, which is completely independent in the Scatopsinae, actually corresponds to the dorsal half of the proepimeron. In
Anapausis
, the sclerite is only partially separated from the ventral half of the sclerite (but this incision is deeper than in
Psectrosciara
and is synapomorphic for
Anapausis
within the Psectrosciarinae). The elongated shape of the body in the
Psectrosciara
is apomorphic and, although the stout shape of
Anapausis
species helps to distinguish it from
Psectrosciara
, it is a plesiomorphic condition. Similarly, the presence of a single seta on the pedicel of the halter and the presence of a tubular aedeagus in
Anapausis
distinguish the genus from
Psectrosciara
, but these are also plesiomorphic features. Macrotrichia on the wing membrane, the genital vesica attached to the male terminalia, and the undivided cercilike T
10 in
females are
Scatopsidae
ground plan conditions, preserved in
Anapausis
. The apomorphic condition of M1, basally interrupted, is shared with
Psectrosciara
(homoplastic with other genera in the family). The antennal flagellum has 8 flagellomeres (a plesiomorphic condition in scatopsids), with the exception of the 7segmented flagellum in
A. inermis
. The palpus (
Fig. 1
) is not as small as in Aspistinae or
Ectaetiinae
, and the absence of an evident sensory pit is a distinctive feature of the genus. There is a long row of setae at the inner apex of tibia I (
Fig. 2
).
The male terminalia of the species of
Anapausis
are probably one of the most complex in all
Diptera
. There are considerable differences between the species of the genus in the shape of the numerous terminalia sclerites, and establishing robust hypotheses of homology is indeed difficult. Different from other scatopsid genera, tergites and sternites 7 and 8 (and, in some cases, sternite 6 and even sternite 5, as in the
soluta
group;
Haenni & Brunhes 1981
,
Fig. 2
;
Chandler 1999
,
Figs. 1–4
) take part in the structure of the terminalia (
Figs. 3–5
). The modified larger anteroventral sclerite probably is sternite 6. A pair of lobose sclerites on each side ventrally with numerous setae in some species corresponds to sternite 7. Tergite 7 forms a large dorsal shield (different from most other genera of the family, in which tergite 7 simply does not take place in the structure of the terminalia).
Tergite 8 is recognizable dorsally because of the pair of spiracles, but it is difficult to recognize tergite 9 (= epandrium), which in most scatopsid species is present as an independent plate. It does not seem plausible that a quite large plate in many species of
Anapausis
would be tergite 9 because it is posterior to the anus. Therefore, tergite 9 is probably fused to tergite 8, and the distal plate would be an oddly developed sternite 10, ventral to the anal opening. Tergite 10 would not be discernible in most species, but might be present in some cases. The aedeagus is conspicuous, usually with a tubular distal ending. In all species of the genus, there is a mesal anterior projection named pseudopenis by
Cook (1965)
, which is not homologous to the “pseudopenis” of
Aldrovandiella
of
Cook (1955)
(=
Rhegmoclema
), synapomorphic for
Anapausis
. The cerci seem to be absent in the groundplan of the genus. Sternite 8 is usually reduced to a short strip across the terminalia, maybe fused to sternite 9, which is also unrecognizable as an independent plate. The gonocoxite, even when recognizable, lost its original shape; the gonostyle is maintained only in some of the species of the genus.
FIGURE 1.
Anapausis absoluta
(Edwards)
, Kenya, Mt Kenya (NHM). Head.
In the female, sternite 8 varies considerably, in some cases keeping gonapophyses 8, also seen in many other genera of the family, but sometimes bearing only a pair of lateral, setose lobes. Internally, there is a pair of large lateral bursae of unknown function associated with segment 8, unique for
Anapausis
. The genital furca is usually wide and rounded posteriorly, not Yshaped, as in many dipteran groups. Tergite 8 is fused to tergite 9 and bears a pair of well sclerotized spiracles anteriorly; the shape of the distal margin varies among species. Tergite 10 is undivided, as also occurs in the Aspistinae and the
Ectaetiinae
, different from the Scatopsinae, in which this plate is divided into a pair of lobose plates (misunderstood by
Cook, e.g. 1981
, as the cerci). The single spermatheca is spherical and sclerotized, except in
A. baueri
Fritz
in which it is pear shaped. This species is thought to be parthenogenetic (
Fritz 1983
).
FIGURE 2.
Anapausis irritata
Cook. Inner
apex of tibia I.
Key to the Neotropical species of
Anapausis
(male of
A. mourei
unknown)
1. M1 at base directed towards M1+2; pedicelar setae absent; in males, a pair of articulated sclerites (S10) distally on T8+9; gonostyles recognizable, deeply bifid (
Figs. 7
,
8
,
16
); S6 not taking part in terminalia; S7 not lobose; vesica largely developed; aedeagus distal tubular projection short ............................................................................................ 2
M1 at base directed toward R5; 1 pedicelar seta; in males, S10 not projected distally; gonostyles absent; S6 with modifications on distal margin; S7 reduced to a pair of setose lobes connected by mesal bare strip; vesica small (
Figs. 23
,
31
); aedeagus distal tubular projection elongated ......................................................................................... 3
2. S10 sclerites slender, digitiform, pointed at apex; parameres not deeply bifid (
Figs. 16
)
.............................................................................................
A. mayana
sp. nov.
Panama
S10 with rounded inner projection close to apex; parameres strongly bifid (
Figs. 7
,
8
)
...........................................................................................
A. wirthi
sp. nov.
Costa Rica
3. Females.......................................................................................................................... 4
Males ............................................................................................................................. 6
FIGURES 3–5.
Anapausis absoluta
(Edwards)
, Kenya, Mt Kenya (NHM). Male terminalia.
3.
Ventral view.
4.
Dorsal view.
5.
Lateral view.
4. Female T8+9 with distal incision and a mesal sclerotized “tooth” directed posteriorly (
Figs. 27
,
36
) ................................................................................................................. 5
Female T8+9 without posterior incision and without wellsclerotized “tooth” directed posteriorly (
Fig. 25
)
........................................
A. clivicola
sp. nov.
Southeastern
Brazil
5. “Tooth” on female T8+9 well developed (
Fig. 27
) .........................................................
............................................................................
A. mourei
sp. nov.
southeastern
Brazil
“Tooth” on female T8+9 short (
Fig. 36
)
........................
A. fuscinervis
(Edwards)
Chile
6. S6 posterior projections smooth; S7 lobose; Gs not detectable (
Fig. 23
) ......................
.........................................................................
A. clivicola
sp. nov.
Southeastern
Brazil
S6 posterior projections with small scalelike projections; S7 more flattened, Gs present, digitiform (
Fig. 33
)
...........................................
A. fuscinervis
(Edwards)
Chile