Anacroneuria guambiana Zúñiga & Stark, 1999

Stark, Bill P., Kondratieff, Boris C. & Gill, Brian, 2012, New Species And Records Of Anacroneuria (Plecoptera: Perlidae) From Ecuador And Paraguay, Illiesia 8 (6), pp. 78-93 : 82-83

Anacroneuria guambiana Zúñiga & Stark

( Figs. 11-13 )

Material examined. Ecuador, Napo Province, 6.38 km W Baeza, Hwy E-20, 1,987 m, 25 January 2012, B.C. Kondratieff, B. Gill 1♂, 1♀, 1 larva, 1 exuvium ( CSUC) . Napo Province, 8.68 km NW Baeza, Hwy E- 20, 2,134 m, 24 January 2012, B.C. Kondratieff, B. Gill, 1♂, 1 exuvium ( CSUC) .

Larva. Body length pre-emergent female 16-17 mm. General color brown, patterned with dark brown. Head brown with pale areas at frontoclypeus, M-line, lateral to ocelli and over most of occiput ( Fig. 11 ); Mline incomplete adjacent to pale mesal spot. Pronotum brown but with pale leg shaped areas adjacent to median suture, and with a few additional pale rugosities. Lateral pronotal setal fringe incomplete anterolaterally. Femora pale brown but darker along ventral and apical margins; fine setal fringe well developed; basal patch of short thick setae extensive along dorsal margin; transverse setal row consists of ca. 7 long, thick setae; scattered thick setae sparse beyond transverse row and with ca. 16 on lower half of femoral surface. Ventral margin with a few thick setae and interspersed fine short setae ( Fig. 12 ). Abdomen dark brown but apical segments with a small median pale spot ( Fig. 11 ), terga without apparent intercalary setae. Cerci without welldeveloped fine setal fringe ( Fig. 13 ), only a few fine setae occur along dorsal margin of apical segments; cercal segments bear apical whorls of short, thick setae, except on some basal segments.

Comments. The male specimen from the first site listed above varies slightly from typical A. guambiana specimens in having the apical aedeagal section with convergent lateral margins and in having the aedeagal shoulders approaching the apical section at an obtuse angle. Larger samples are needed to resolve whether this specimen represents a sibling member of the A. guambiana complex. The larva is generally similar to that of A. paleta Stark 1995 ( Maldonado et al. 2002), but that species has a complete M-line and more extensive dark pigment on the occiput. These specimens are the first representatives of this species to be reported for Ecuador.

The first site listed in the materials section above ( Figs. 32-33 ) is located in the lower montane cloud forest at 1,987 m, and is composed mainly of alternating step-pools. The substrate ranges from depositional fines to large boulders, however, size extremes of sand and boulders dominate. The stream channel has numerous debris dams and downed trees from adjacent riparian zones. Steep walls surrounding the stream are covered with plants that confine the channel and create approximately 71% canopy cover. The channel is 1.56 m wide and depth averaged 0.13 m. Discharge measured during the collection at this site was 37.1 L s-1. Interestingly, the substrate was partially covered at the time of the collection by filamentous algae not typically seen in the region. The second stream ( Fig. 34 ) is characterized by stretches of cobble filled riffle between cascades formed by large boulders. The channel is braided and narrow at various points, and is relatively free of debris dams or downed trees. Channel width is 2.32 m and depth averages 0.19 m. Discharge was measured at 105.3 L s-1 during collecting. Canopy cover varies from open to closed along the channel. Adjacent riparian areas are composed of vegetation typical of lower montane cloud forest.

Figures

Figs. 11-13. Anacroneuria guambiana larval structures. 11. Head, pronotum and terminal abdominal segments. 12. Left fore femur. 13. Cercal segments 5-7, 16-18, 31-33, lateral.

Figs. 32-35. Ecuadorian collecting sites. 32. Napo Province, 6.38 km W Baeza, 1,987 m. 33. Same site as previous figure. 34. Napo Province, 8.68 km W Baeza, 2,134 m. 35. Napo Province, 2.78 km W Papallacta, 3,296 m.