Isoperla maculata Zhiltzova, 1977

Teslenko, Valentina A. & Zhiltzova, Lidiya A., 2006, Nymphs of the genus Isoperla Banks (Plecoptera, Perlodidae) from the Eastern Palaearctic Region, Zootaxa 1130, pp. 1-33 : 17-20

Isoperla maculata Zhiltzova, 1977

( Figs.42–48)

Description. Association was established by rearing nymphs from the Barabashevka River. Length of mature male nymph 8.8–9.0 mm, female 10.0– 10.5 mm; cerci of male nymph 3.8–4.0 mm; female 4.7 –5.5 mm. General body color brownish­yellow with distinct dark brown pattern on head, thorax and abdominal terga, venter yellowish. Clothing hairs dark, occipital setae light and short.

Head with occiptal spinule row incomplete, dark­brown ( Fig. 42) M­shaped pigment pattern between antennal bases; ocelli connected by dark pigment; interocellar area pale and open posteriorly; clypeus and labrum yellow­brownish, without spots. Lacinia bidentate ( Fig. 43 ), triangular; inner margin with 4–5 stout setae and a few short and thin setae below subapical tooth; galea reaching base of subapical tooth. Mandible similar to other species ( Fig. 44 ).

Thorax. Pronotum ( Fig. 42) transverse­oval, evenly fringed with long pale setae, occasional longer setae interspersed at upper and lower angles and at lateral margins; middle of pronotum with large, pale, cross­shaped spot surrounded by dark pigment. Lateral margins of pronotum pale. Meso­ and metanotum ( Fig.42) with pale, median patches widest anteriorly; lateral margins and tips of wing pads pale. Legs pale ( Fig. 45 ) with silky fringe hairs on femora, tibiae, and tarsi.

Abdominal terga ( Fig. 42) with narrow dark stripe medially, contrasted by pale stripes; sublateral dark stripes are bracketed by pale lines. Intercalary bristles visible on dark longitudinal tergal stripes. Cerci ( Figs. 46–48 ) yellowish­brownish; apical half with dorsal fringe of long silky hairs; apical whorl in apical third of cerci with short setae and one dorsal and one ventral long seta whose length does not exceed half the length of its corresponding segment.

Material examined: Russia. Primorsky Region, Barabashevka R., 9.VI 2003, V. Teslenko, 27 nymphs (reared); the same place, 4.VI 2002, V. Teslenko 15 nymphs; Margaritovka R., 14.VI 1998, V. Teslenko, 3 nymphs; Milogradovka R., 13.VI 1998,V. Teslenko, 3 nymphs; Kievka R., 13.VI 1998, V. Teslenko, 3 nymphs; Isvilinka R., Ussuri R.Basin, 15.VI 1998, V. Teslenko, 2 nymphs; Khabarovsky Region, Sukpai R., Khor R. Basin, 22.VI 1998, V. Teslenko, 4 nymphs.

Distribution. Russia: Amur River Region, Khabarovsky and Primorsky Regions; Mongolia.

Figures

FIGURES 43 – 48. Isoperla maculata: 43. Right maxilla, ventral. 44. Right mandible, ventral. 45. Right leg, dorsal. 46 – 48. Basal, medial, and apical sections of right cercus, lateral. Scale (mm): 45 = 0.5 mm; 43, 44, 46 – 48 = 0.1.