Compterosmittia Saether

Humberto F. Mendes, Trond Andersen & Ole A. Saether, 2004, A review of Antillocladius Saether, 1981; Compterosmittia Saether, 1981 and Litocladius new genus (Chironomidae, Orthocladiinae), Zootaxa 594, pp. 1-82 : 59-62

Compterosmittia Saether

Compterosmittia Saether, 1981: 20 ; Cranston et al. (1989: 186); Saether (1982: 491); Cranston and Oliver (1988: 429); Cranston and Kitching (1995: 229).

Type species

Compterosmittia dentispina Saether, 1981 , by original designation.

Other included species

Compterosmittia aberrans new species; C. berui new species; C. claggi ( Tokunaga, 1964: 506, as Metriocnemus , possible synonym of C. nerius ); C. croizati new species; C. nerius ( Curran, 1930: 34, as Camptocladius , syn. clavigera Saether, 1982 ); C. pectinata ( Freeman, 1961: 662, as Gymnometriocnemus ); C. pittieri new species; C. tuberculifera ( Tokunaga, 1964; 530, as Smittia ); C. virga Wang, 1998 .

Diagnostic characters

The imagines can be separated from other orthoclad genera by having scalpellate acrostichals in the middle of scutum, or in C. croizati new species and C. virga Wang starting closer to antepronotum, combined with bare squama, very long costal extension, and often absence of virga and dentate megaseta. All known females and several males have setae apical on the wing membrane. The pupa is not separable from Limnophyes Eaton. The only differences between the larvae of Limnophyes and Compterosmittia consist in the mandible which has 4 inner teeth in Compterosmittia , 3 in Limnophyes ; and in that the supra­anal seta is 1/3 the length of the anal setae in Compterosmittia , much longer in Limnophyes .

Generic diagnosis

Imago

Small species, wing length 0.7–1.3 mm.

Female antenna with 5 flagellomeres. Male antenna with 10–13 flagellomeres, groove beginning at flagellomere 3, sensilla chaetica on flagellomeres 2, 3 and 13. Male antennal ratio 0.5–1.0.

Head. Eye naked, with or without minute pubescence between ommatids, without dorsomedial extension. Temporal setae divided into weak inner verticals, stronger outer verticals, postorbitals absent or few. Third palpomere with about 1–3 sensilla clavata apically, longest 8–17 µm long.

Thorax. Antepronotum well developed, lobes meeting medially along short suture. Acrostichals, short, all scalpellate in the middle of scutum or starting about 1/3 of scutum length from antepronotum; prealars uniserial; supraalar 0–1; scutellars uniserial.

Wing. Anal lobe protruding or absent. Costa strongly extended. R2+3 running and ending midway between R1 and R4+5; R4+5 ending opposite or slightly distal to M3+4; FCu far distal to RM; Cu1 nearly straight to distinctly sinuous; An ending proximal to FCu. Veins bare or with setae on R, R1, R4+5, and/or M1+2,. Membrane with apical setae in female; male without setae , with few weak setae apically in cell r4+5, or with several setae apically in cells r4+5, and m1+2. Squama bare.

Legs. Pseudospurs, sensilla chaetica and pulvilli lacking. Comb and tibial spurs normal.

Abdomen. Tergites with irregularly arranged setae .

Hypopygium. Anal point moderately long, sharply to bluntly pointed, with mostly strong lateral setae , with microtrichia only at base or nearly to apex. Phallapodeme and aedeagal lobe well developed. Anterior margin of sternapodeme arcuate, oral projections moderately to strongly developed. Virga absent or, in C. virga , consisting of 16–18 spines. Inferior volsella simple, rounded and projecting or with anterior microtrichia­free, digitiform anterior projection and low to prominent posterior lobe.

Gonostylus without heel; crista dorsalis absent. Megaseta often dentate.

Female genitalia. Gonocoxapodemes curved and meeting anterior of vagina. Gonocoxite relatively well developed, with several long setae and a few short setae . Tergite IX divided. Gonapophysis IX with large ventrolateral lobe covering apodeme lobe and apex of narrow, line­like dorsomesal lobe. Labia small. Cerci normal. Seminal capsules long, with triangular, pale neck. Spermathecal ducts with large loop and common opening.

Immatures

The immatures of one species are described by Cranston and Kitching (1995). Except for the characters mentioned in the diagnostic characters, the diagnoses for both pupa and larva are identical to those given for Limnophyes by Saether (1990: 9).

Key to the males of Compterosmittia Saether

1. — 2. — 3.

— 4. — 5.

— 6. — 7.

Virga consisting of 16–18 spines; China................................................. C. virga Wang Virga absent ................................................................................................................... 2 Inferior volsella a rounded strongly projecting simple lobe ......................................... 3 Inferior volsella with an anterior, dorsal, digitiform, bare lobe and a posterior, ventral, more rounded, more or less well developed lobe.......................................................... 6 Anal point well developed with several strong lateral setae ; Australia.......................... .................................................................................................. C. pectinata (Freeman) Anal point short with few and weak setae .................................................................... 4 Megaseta not dentate ( Fig. 19 D); Venezuela, Brazil................. C. croizati new species Megaseta dentate .......................................................................................................... 5 Anal lobe present, Cu1 moderately sinuous; Micronesia, Bonin Is., Guam, Belau......... ........................................................................................... C. tuberculifera (Tokunaga) Anal lobe reduced, Cu1 strongly sinuous ......................................... C. nerius (Curran) New York, South Carolina; and C. claggi (Tokunaga) Bonin Is. , Belau, Micronesia Megaseta strongly dentate; St. Vincent, St. Kitts......................... C. dentispina Saether Megaseta apparently simple ......................................................................................... 7 Antennae with 10 flagellomeres; inferior volsella with prominent elongate ventral part — 8.

— ( Fig. 17 F); Costa Rica............................................................. C. aberrans new species Antennae with 13 flagellomeres; inferior volsella either with reduced elongate ventral part or with posterior ventral part short and rounded................................................... 8 Anal point narrow, sharply pointed; posterior ventral part of inferior volsella low and elongate; no supraalar ( Fig. 18 D); Brazil...................................... C. berui new species Anal point moderately long with blunt apex; ventral part of inferior volsella prominent, short and rounded; supraalar present ( Fig. 20 D); Venezuela................................. .................................................................................................... C. pittieri new species

Figures

FIGURE 17. Compterosmittia aberrans new species, male imago. A – head; B – cibarial pump, tentorium and stipes; C – thorax; D – wing; E – anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; F – hypopygium with anal point and tergite IX removed, left dorsal aspect, right ventral aspect.

FIGURE 18. Compterosmittia berui new species, male imago. A – cibarial pump, tentorium and stipes; B – thorax; C – wing; D – anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; E – hypopygium with anal point and tergite IX removed, left dorsal aspect, right ventral aspect.

FIGURE 19. Compterosmittia croizati new species, male imago. A – cibarial pump, tentorium and stipes; B – thorax; C – wing; D – anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; E – hypopygium with anal point and tergite IX removed, left dorsal aspect, right ventral aspect.

FIGURE 20. Compterosmittia pittieri new species, male imago. A – cibarial pump, tentorium and stipes; B – thorax; C – wing; D – anal point and tergite IX and dorsal aspect of left gonocoxite; E – hypopygium with anal point and tergite IX removed, left dorsal aspect, right ventral aspect; F – gonostylus.