Isoperla kozlovi Zhiltzova 1972

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 : 13-15

Isoperla kozlovi Zhiltzova 1972

( Figs. 29–34 )

Description. The nymph of I. kozlovi was originally described by Beketov (2004). However, the illustration of the habitus was very small and did not include abdominal pigment pattern. Length of mature nymph 7.5–8.6 mm. General body color yellow with light­brown pattern on the head, thorax, and abdomen; antennae light; dorsum of body covered with clothing hairs.

Head ( Fig.29 ) with occiput spinule row interrupted medially; wide, brown, transverse band between antennal bases, delimited posteriorly by epicranial suture and anteriorly by pale M­line; interocellar area with small oval, pale spot. Lacinia bidentate, with five long setae below subapical tooth, galea short, its tip does not reach the base of subapical tooth ( Fig. 30 ). Mandible with six unserrated teeth ( Fig. 31 ).

Thorax. Pronotum fringed with short, thick setae, their tips obtuse and dilative ( Beketov 2004). Medial pronotal band lighter than submedial areas; lateral pronotal margins pale, anterior margin dark ( Fig. 29 ). Meso­ and metanotum pale medially, wing bases dark, and apical parts pale. Legs light ( Fig. 29 ) with fringe of silky swimming hairs along outer margin of femur and tibia.

Abdominal terga ( Fig.29 ) with three dark stripes, one medially the others submedial, each consisting of dark spots that widen on the anterior of each tergite; dark stripes alternate with four pales ones; posterior terga margin with fringe of pale setae that elongate laterally. Cerci ( Figs. 32–34 ) in apical half with dorsal fringe of long silky hairs; apical whorl in apical third with one ventral seta longer than others.

Material examined: Russia. Novosibirsk, Inya R., 20.V 2003, M. Beketov, 3 nymphs, 1 exuvium; the same place, 18.V 2003, M. Beketov, 2 exuvia; the same place, 17.V 2003, M. Beketov, 1 exuvium; Kazakhstan. Malaya Ubinka R., Set. Bystrukha, 25. V 2003, V. Devyatkov, 15 nymphs.

Distribution. Russia: West Siberia, Sayan Mnts., Transbaikal Region, Amur Region, Khabarovsky and Primorsky Regions; Kazakhstan; Mongolia.

Figures

FIGURES 29 – 34. Isoperla kozlovi Zhiltzova: 29. Habitus. 30. Maxilla, ventral. 31. Mandible, ventral. 32 – 34. Basal, medial, and apical sections of right cerci, lateral. (Figs. 30 – 34 borrowed with permisson from Beketov 2004).