Parorthocladius

Makarchenko, Eugenyi A. & Makarchenko, Marina A., 2015, A review of the genus Parorthocladius Thienemann, 1935 (Diptera: Chironomidae: Orthocladiinae) from the Russian Far East, Zootaxa 3974 (3), pp. 413-423 : 421-422

Parorthocladius sp. 1

( Figs. 29–32 )

Material: 1 pupa with larval skin, Primorye Territory, Terneisky District, Sikhote-Alin’sky State Nature Reserve, Zimoveiny Stream of Serebrianka River basin, 23.VIII. 2006, leg. O. Zorina.

Pupa (n=1). Colouration dark brown.

Cephalothorax. Frontal apotome without tubercles and frontal setae. Thoracic horn 52–56 µm long, 24 µm wide, oblong-rounded, transparent and naked ( Figs. 29–30 ). Pore and 3 precorneals placed near thoracic horn ( Fig. 29 ). Distance between Pc1 and Pc2 52–80 µm; distance between Pc2 and Pc 3 12–24 µm. Antepronotum with 2 middle setae and 1 lateral seta. Dorsal surface of mesonotum rugose, with 1–2 rows of pointed tubercles. Three hair-like dorsocentrals; distance between Dc1 and Dc2 136–140 µm; between Dc2 and Dc 3 14–24 µm.

Abdomen. Tergite I missing. Tergite II with two spots of small spinules in anterior part. Tergite III with two spots of small spinules in anterior part and two spots in posterior part. Tergite IV–V with two spots of small spinules in anterior part and with transverse stripe of larger spinules at posterior edge; spinules sparse between anterior and posterior shagreen ( Fig. 31 ). Shagreenation of tergite VI as on tergites IV–V but size of spinules in anterior part almost equal to that of posterior part. Tergites VII–VIII with anterior and posterior stripes of spinules of almost equal size. Sternites without shagreen. Segments II–VIII with 3 pairs of short and hair-like lateral setae. Male genital sac overreaching anal lobe. Anal lobe length 216 µm. Anal macrosetae 92 µm long. Anal macrosetae length/anal lobe length 0.42.

Fourth instar larva (1 larval skin). Head. Head capsule dark brown. S I–IV of labrum simple and hair-like. Pecten epipharyngis consisted of 3 scales. Premandible ca 60 µm long, with 1 tooth. Antenna with 5 segments, length of segments 1–5 (in µm): 49–50: 15–16: 6: 8: 5; segment 3 shorter than segment 4; large ring organs in proximal 1/4 of basal segment; apex of segment 2 with stylus; lauterborn organs well developed; blade ending at apex of segment 5 ( Fig. 32 ); AR 1.37–1.43. Mandible 92–96 µm long, with 3 equal inner teeth and 1 apical tooth. Mentum with broken apical part and 4 pairs of lateral teeth. Procercus with 2 short lateral setae and 6 apical setae 224–480 µm long. Body segments with 6 pairs of branched setae.

Remarks. Among all species of the genus Parorthocladius recorded from the Far East this is the only pupa having the thoracic horn, which is similar to that of P. nudipennis . However, shagreenation of tergites and sternites of these two species is different. Larva is similar to those of other known species and can be separated only on the basis of antennal characters (see key above).

Distribution. Known from Primorye Territory of the Russian Far East.

Figures

FIGURES 29 – 32. Parorthocladius sp. 1, pupa (29 – 31) and larva of fourth instar (33). 29, thoracic horn and precorneals; 30, thoracic horn; 31, tergites II – IV; 32, antenna. Scale bars: Figs. 29 – 30 — 50 µm; Fig. 31 — 200 µm; Fig. 32 — 20 µm.