Antarctoperlinae, Enderlein, 1909

McLellan, Ian D. & Zwick, Peter, 2007, New Species Of And Keys To South American Gripopterygidae (Plecoptera), Illiesia 3 (4), pp. 20-42 : 27-29

Antarctoperlinae gen. sp. I

( Figs. 18 ‐ 23 )

Material examined. 1 LA Chile, Malleco, Vegas Blancas, 27 km W Angol , 700 m, 17 January 1987, CMF & OSF ; 1 LA Chile, Llanquihue Prov., a stream 15 km SW of Las Quemas 17 December 1972, MLP ; 1 LA Chile, Osorno, Rio El Gringo Park , Puyehue, 1075 m, 13 December 1972, MLP; 2 female LA, Chile, Malleco, Vegas Blancas, 27 km W Angol , 700 m, 17 January 1987, CMF & OSF .

Dimensions. Larva (last instar): body length, 9.0 ‐ 10.0; antenna, 5.0 ‐ 7.0; cerci, 1.0.

Larva. Pale brown, with a sand like matt surface; indistinct muscle attachments on head and thorax a darker brown; a brown ring across widest part of antennal flagellum, subgenual rings and apices of tibiae dark grey. Hairless, except as mentioned below.

Head: Rounded, massive. Eyes large, no ocelli. Unpaired cephalic suture long, well visible, its fork distinct; depression in front of fork deep. Frons bulging over downwardly directed clypeus and labrum. Mandible ( Fig. 19 ) with large sharp pointed teeth ventrally and a dorsal elongate oval spiny mola and a faint prosthecal hair brush but no other hairs; a transverse row of sensilla inward from ventral condyle. Maxilla ( Fig. 20 ) with 5 ‐ segmented simple palp, basal segment very short, in ventral view not easily distinguished from palpiger. Galea simple, a few outwardly turned elongate sensilla at apex, medial face closely appressed to lacinia. Lacinia very broad at base, especially from lateral view, strongly tapered to narrow tip which has three very dark sharp slender teeth. Basally from teeth along mediodorsal edge are a series of pale setae with about five of the apical ones modified into large spike ‐ like structures. Antennae ( Fig. 18 ) almost as long as body, scape large, and pedicel dark and basally strongly constricted. Flagellum distinctly enlarged basally with a dark band, segments on wide part very short and transverse, scarcely discernable, only distinguished by rings of curved short setae; distal segments narrow, almost twice longer than wide, hairless.

Thorax. Dorsum flat and much wider than parts below. Laterally flanged with a sharp edge, along which there is a row of small sharp pale setae. Pronotum with all four angles produced into prominent angular lobes. Mesothoracic wing pads with parallel sides and free distal parts only about as long as wide. Metathoracic wing pads divergent and shorter. Legs simple, long, with inconspicuous pilosity. Outer face of tibiae with a series of 4 ‐ 7 long pale hairs along a narrow bare longitudinal space between two regular rows of very short setae. No tibial spurs, but a few stronger setae ventrally at apex. Tarsi ( Fig. 21 ) ventrally with fine hair brushes, dorsally with some thin hairs. First segment longer than wide with narrow base, Segment 2 incomplete, a ventral lobe dorsally divided completely by insertion of segment 3; segment 3 longer than first two together.

Abdomen formed of 10 complete segmental rings, each of the first nine medially strongly constricted, with fringe of setae arising from dark spots along bulging distal edge ( Fig. 22 ). Most setae are short, truncate, of variable length but some long, extending into a soft pale filament which is probably broken in the truncate setae. Ventrally, the distal bulges are less prominent, setae are shorter, soft, pale, appearing woolly. Segment 10 ( Fig. 23 ) forms a distally obliquely truncate cylinder and bears a regular fringe of short setae posteriorly along its upper edge. The ventrodistal opening of the segment is almost completely covered by the flat, hard subanal lobes from which rise a short hard apical spine. Cerci minute, pale and sparsely pilose; the longer one with seven segments but both are probably broken. The pale tips of numerous retracted gill filaments project between the subanal lobes.

Remarks. The width and seeming shortness of the wing pads results from their flanged nature; the adult is probably fully winged. The mandibular mola resembles the “Stachelmola” as illustrated for Brachyptera, Wichard et al., 1995 .

Figures

Figs. 18‐23. Antarctoperlinae gen.sp. I, larva.18, habitus; 19, left mandible, ventral; 20, left maxilla, ventral; 21, tarsus, lateral and dorsal; 22, lateral part of tergal hair fringe; 23, abdominal tip, ventral. Figs 19‐21 to same scale, 22‐23 not to scale.