Tokunagaia lagutini Makarchenko et Makarchenko, 2017

Makarchenko, E. A. & Makarchenko, M. A., 2017, A new species of the genus Tokunagaia Sæther, 1973 (Diptera: Chironomidae: Orthocladiinae) from the Russian Far East, Far Eastern Entomologist 343 (343), pp. 19-24 : 20-24

Tokunagaia lagutini Makarchenko et Makarchenko , sp. n.

Figs 1–16

total view of hypopygium (holotype) from above; 2 – thoracic horn and precorneal setae; 3 –

distal part of thoracic horn; 4–5 – thoracic horn; 6–7 – dorsocentral setae of thorax; III; 8 –

mandible; 9 – premandible; 10 – antenna; 11–12 – mentum. Scale bars for Figs 1–2, 4–7 are

50 µm, for Figs 8–12 are 20 µm.

long, with more wide basal part (46–49% of total length) and narrow distal part ( Figs 2, 4–5 ),

which may be covered by short and thin spinules in apical part ( Fig. 3 ). Precorneals length:

Pc 1 –72 μm, Pc 2 –76–108 μm, Pc 3 –56 μm. Pc 2 more strong than other precorneals.

posterior rows of spinules of tergite IV; 16 – posterior rows of spinules of tergite VII.

Abdomen. Tergite I without shagreen. Tergites II–VI with evenly shagreen of small spinules; in posterior part with row of narrow spines 12 μm long. Tergites III–V after narrow posterior row of long spinules with row of caudal hooklets, number of which on these tergites respectively 17–26, 20–23, 21–22 ( Figs 13, 15 ). Tergites VI–VIII without caudal hooklets, only with posterior spines and tender shagreen ( Fig. 16 ). Tergite IX with shagreen of small spinules. Sternites I–III without shagreen of spinules. Strnites IV–VIII with shagreen of spinules along posterior edge. Sternite IX with small spinules in anterior half.

Segments I with 1–2 pairs of lateral setae. Segments II–VIII with 4 lateral setae L 1 and L 2

located side by side. Length of lateral setae L 1 –L 4 of segment VIII respectively 16–24 µm,

72–88 µm, 40–52 µm, 28–36 µm. Anal macrosetae 140–148 µm long. Anal lobe length 260–

268 µm. Genital sac of male overreaching anal lobe by 12–28 μm ( Fig. 14 ).

Head dark-brown. Labral setae SI–SIV simple. Antenna with 5 segments; AR 1,5–1,73.

First segment with large ring organ in basal part and small ring organ distal of middle part;

laurerborn organs good visible and the same length as segment 3; blade of second segment rich to base and sometime apex of 5th antennal segment ( Fig. 10 ). Premandible with 1 wide apical tooth. Mandible with 1 apical and 4 inner dark brown or black teeth and 2 seta-like long molar spines; apical tooth the same length as first of inner tooth; seta subdentalis rich to

3 rd inner tooth; seta interna branched to 5 parts. Pecten galearis of maxilla absent. Mentum

62–66 µm wide, with 2 middle tooth and 5 pairs of lateral teeth; middle teeth good separated;

one of middle teeth in 1.3–1.7 times wider of first lateral tooth; ventromental plates good visible, in basal part with bend and rounded apically ( Figs 11–12 ); postmentum 160–168 µm

long.

Abdomen. Abdominal segments setae rare and shorter of ½ of segment length. Supraanal seta length 40–80 μm. Width of procercus is equal to their length, with 7 anal setae of different length: 3 setae 224–300 μm long, 4 setae 120–200 μm long; and with 2 weak lateral setae.

Anal tubules shorter of posterior pseudolegs. Posterior pseudolegs at base in 1.7–2 times longer than their width.

DIAGNOSIS AND COMMENTS. T. lagutini sp. n. is close related to the Palaearctic T.

rectangularis (Goetghebuer, 1940) and adult male can be distinguished from latter by LR 1

(0.62–0.66), HV (2.71–3.01), rectangular-rounded inferior volsella and more short (80–88

μm) gonostylus. Male of T. rectangularis with LR 1 0.74, HV 3.1–3.47, inferior volsella rectangular, gonostylus length 90–98 μm (Halvorsen & Saether, 1987). Pupa of T. lagutini sp.

n. with thoracic horn, which is not typical for the genus Tokunagaia and the diagnosis of which indicates that the thoracic horn is absent. However, we have previously described pupa of T. oleantoni Makarchenko et Makarchenko , which also lacked thoracic horns (Makarchenko & Makarchenko, 2007). If do not take into account the presence of the thoracic horn, the pupa of the new species is close related also to T. rectangularis which have total length 3.06–3.78 mm, tergites III–V with 32–51 hooklets in posterior row, segment VIII with

2 pairs of lateral setae and genital sac of male overreaching anal lobe by 56–75 μm

(Halvorsen & Saether, 1987). Total length of pupa T. lagutini sp. n. 2.5–2.95 mm, tergites

III–V with 17–26 hooklets in posterior row, segment VIII with 4 pairs of lateral setae and genital sac of male overreaching anal lobe by 12–28 μm. Larvae of both species are very similar and can be separated only two features. Larva of T. lagutini sp. n. with 4 inner teeth of mandible and 2 seta-like molar spines, while larva of T. rectangularis with 3 inner teeth of mandible and 3 seta-like molar spines (Halvorsen & Saether, 1987).

We believe at present there is a need to revise the genera Tokunagaia and Eukiefferiella due to the fact that the pupae of species T. oleantoni and T. lagutini sp.n. have thoracic horns and do not conform to the diagnosis of this genus. At the same time, the males of some species of the genus Eukiefferiella (E. ternus Makarchenko et Makarchenko, E. claripennis

Lundbeck, E. intermedia Makarchenko et Makarchenko and E. limuri Makarchenko et

Makarchenko) also do not correspond to the diagnosis of this genus, since hypopygium of these species with virga, which is characteristic of the genus Tokunagaia . In our opinion, for the removal of disagreements in the taxonomy and systematics of genera Tokunagaia and

Eukiefferiella it seems reasonable to close the genus Tokunagaia , which was erected mostly with using adults without investigation of the preimaginal stages (Saether, 1973; Halvorsen &

Saether, 1987).

ETYMOLOGY. The species is named in honor of inspector of the Bolshekhekhtsirsky

Nature Reserve and driver of the cross-country vehicle S.V. Lagutin, thanks to which it was possible to gather material in the inaccessible corners of the reserve.

DISTRIBUTION. New species is known only from the type locality in Khabarovskii krai.

We are grateful to Dr. N.M. Yavorskaya (Institute of Water and Ecological Problems

FEB RAS, Khabarovsk) for making material available to us and to Dr. R.S. Andronova (the

Joint Directorate of State Natural Reserves and National Parks of Khabarovsk Territory

“Zapovednoye Priamurye”, Khabarovsk) for support of investigations in Bolshekhekhtsirsky

Nature Reserve. This study was supported partly by the grant No 17–1–1–004e of the Far

East Program of Presidium Far Eastern Branch of the Russian Academy of Science.

Figures

Figs 1–12. Tokunagaia lagutini sp. n., male imago (1), pupa (2–7) and larva (8–12). 1 –

Figs 13–16. Tokunagaia lagutini sp. n., pupa. 13 – tergites III–IV; 14 – anal segment; 15 –