Anapausis Enderlein, 1912

Amorim, Dalton De Souza & Balbi, Maria Isabel P. A., 2006, A review of Anapausis Enderlein (Diptera: Scatopsidae) in the Neotropical Region, with four new species and comments on the phylogeny of the genus, Zootaxa 1300, pp. 1-29 : 4-8

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.

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).

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

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

Figures

FIGURE 1. Anapausis absoluta (Edwards), Kenya, Mt Kenya (NHM). Head.

FIGURE 7. Anapausis wirthi. Holotype, male terminalia, ventral view.

FIGURE 23. Anapausis clivicola. Male terminalia, ventral view.

FIGURE 27. Anapausis mourei, holotype. Female terminalia, lateral view.

FIGURE 31. Anapausis fuscinervis (Edwards). Thorax.

FIGURE 33. Anapausis fuscinervis (Edwards). Male terminalia, ventral view.

FIGURES 3 – 5. Anapausis absoluta (Edwards), Kenya, Mt Kenya (NHM). Male terminalia. 3. Ventral view. 4. Dorsal view. 5. Lateral view.

FIGURES 8 – 10. Anapausis wirthi. Holotype, male terminalia sclerites. 8. Sternite 10. 9. Parameres. 10. Gonostyle.

FIGURES 34 – 36. Anapausis fuscinervis (Edwards). Female terminalia. 34. Ventral view. 35. Dorsal view. 36. Lateral view.

FIGURES 24, 25. Anapausis clivicola. Female terminalia. 24. Ventral view. 25. Dorsal view.