Antillocladius 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 : 23-25

Antillocladius Saether

Antillocladius Saether, 1981: 4 ; Coffman et al. (1986: 160); Cranston et al. (1983: 157); Cranston et al. (1989: 176); Saether (1982: 471; 1984: 1).

Type species

Antillocladius antecalvus Saether, 1981 , by original designation.

Other included species

Antillocladius arcuatus Saether, 1982 ; A. biota new species; A. calakmulensis new species; A. folius new species; A. herradurus new species; A. musci new species; A. pluspilalus Saether, 1982 ; A. scalpellatus Wang and Saether, 1993 ; A. skartveiti Andersen and Contreras­Ramos, 1999 ; A. sooretama new species; A. ubatuba new species; A. venequatoriensis new species; A. zempoalensis new species and A. zhengi Wang and Saether, 1993 .

Diagnostic characters

The imagines can be separated from other orthoclad genera by having scalpellate acrostichals at least in the middle of scutum combined with a moderately to extremely long anal point with lateral setae . (Although A. pluspilalus in the original description is mentioned as apparently having non­scalpellate acrostichals, more recently found specimens show that scalpellate acrostichals are present.) All known females and several males have setae apical on the wing membrane. The combination of absence of thoracic horn and presence of thorn­like macrosetae will separate the pupae from other genera. The larva is distinguished by a palmate S I; pecten epipharyngis divided into about 8–15 teeth; anal segment protruding over posterior parapods; and anal setae absent or perhaps reduced to single seta on minute tubercle.

Generic diagnosis

Imago

Small to medium sized species, wing length 0.8–2.3 mm.

Female antenna with 5 flagellomeres. Male antenna with 13 flagellomeres, groove beginning at flagellomere 3, sensilla chaetica on flagellomeres 2, 3 and 13. Male antennal ratio 0.50–1.70.

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 3 sensilla clavata apically, longest 8–23 µm long.

Thorax. Antepronotum well developed, lobes meeting medially along short suture. Acrostichals, short, all scalpellate or anterior few simple, beginning close to antepronotum, some distance from antepronotum or in the middle of scutum; prealars uniserial; supraalar 0–1; scutellars uniserial.

Wing. Anal lobe protruding to absent. Costal extension moderately to strongly developed (1/2 to 4 times the length of RM). 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 straight to slightly sinuous; An ending proximal to FCu. Veins bare or with setae on R, R1, R4+5, M1+2, M3+4, Cu, Cu1 and An. Membrane with apical setae in female; male without setae , with few weak setae apically in cell r4+5, or with numerous setae apically in cells r4+5, m1+2 and m3+4. Squama bare or with up to 15 setae .

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

Abdomen. Tergites with irregularly arranged setae .

Hypopygium. Anal point long, pointed, with strong lateral setae , with microtrichia only at base or nearly to apex; apex never with setae . Phallapodeme and aedeagal lobe well developed. Anterior margin of sternapodeme nearly straight to strongly arcuate, oral projections barely indicated to strongly developed. Virga absent or consisting of 2–6 long, strong spines. Inferior volsella highly variable; simple and rounded or triangular; with anterior dorsal triangular or digitiform part and a more rounded ventral, posterior part; posterior lobe low to prominent; consisting of a posteriomedially directed, apically simple or bifid lobe; or circular with or without additional rounded posterior extension and conspicuously set off.

Gonostylus with or without heel; crista dorsalis absent to rounded and well developed.

Megaseta normal.

Female genitalia. Gonocoxapodemes curved and meeting anterior of vagina. Gonocoxite relatively well developed, with a few long setae and additional short setae . Tergite IX divided or undivided with setae concentrated to lateral halves. Gonapophysis IX with large ventrolateral lobe covering apodeme lobe and apex of narrow, line­like dorsomesal lobe. Labia relatively large, pointed. Cerci small. Seminal capsules small to medium­sized, circular, with triangular neck. Spermathecal ducts with bends or loops, with weak bulbs before separate openings.

Pupa

Small to medium sized, total length 2.0 to 3.5 mm.

Cephalothorax. Frontal setae absent. Frontal apotome smooth. Antennal sheath with or without pearl row above pedicel. Ocular field with 2 reduced postorbitals. Thoracic horn absent. Three weak precorneals situated in row or narrow triangle. Apparently two median and 0–1 lateral antepronotals. Dorsocentrals very small, in two groups of two. Thorax and wing sheath smooth.

Abdomen. Tergite I without shagreen; tergites II–VIII covered with coarse, shagreen except along anterior margin; tergite IX with strong shagreen except along anterior and posterior margin. Sternites I and II bare; sternite III with median and lateral shagreen; sternites IV–VI with slightly more extensive median and lateral shagreen; sternites VII and VIII with extensive shagreen; sternite IX with anterolateral shagreen. Tergite II without posterior hooklets. Tergites II–VII or VIII with posterior row of weak spines. Conjunctives bare. Pedes spurii A and B absent. Apophyses weak, nearly straight. Segment II–VIII with 2 weak, hair­like L setae . Anal lobe with 3 thorn­like macrosetae, sometimes laterally expanded; male genital sac overreaching anal lobe, female genital sac not reaching apex of lobe.

Larva

Small to medium sized, 3.0– 3.3 mm long.

Head. Antenna 5­segmented, less than half as long as mandible, last three segments short. Blade as long as or longer than flagellum, striated. Lauterborn organs absent, style large. S I nearly palmate with 5–6 teeth, one of them usually larger. Other S setae normal. No discernible labral lamellae. Pecten epipharyngis of 8–15 teeth (each of the normally scales divided into 2–5 teeth). Chaetulae laterales simple, 3 strong and sclerotised, 4–5 weak, pointed and unsclerotised. Chaetulae basales simple or bifid. Mandible with apical tooth shorter than the combined widths of 4 inner teeth, fourth tooth sometimes joined to mola. Seta subdentalis triangular. Seta interna slender, of 4–5 nearly smooth to strongly serrated branches. Mentum with large, irregular triangular, sometimes medially notched median tooth higher than 5 pairs of lateral tooth, fourth pair smaller than fifth and apparently occasionally completely reduced. Ventromental plates small, visible only below 3 outermost teeth, no beard. Maxilla without pecten galearis, lacinial chaeta reduced to rounded lamellae.

Abdomen. Without distinct setae . Anterior parapods fused for most of their lengths, with minute groups of minute claws and some longer mostly smooth claws. Procercus apparently absent, but a vestigial tubercle with one short seta may represent procercus at least in some species. Anal tubules shorter than half the length of posterior parapods (shape not clear in any available material). Posterior parapods well developed, with strong apical claws.