Doncricotopus dentatus Tuiskunen, 1985

Namayandeh, Armin & Beresford, David V., 2021, Review of the genus Doncricotopus (Orthocladiinae: Chironomidae): with the description of a new species from Canada, Journal of Natural History 55 (19 - 20), pp. 1195-1211 : 1197-1199

Doncricotopus dentatus Tuiskunen

( Figure 1 (a-d))

Doncricotopus dentatus Tuiskunen, 1985: 102 , Figs 4–8 .

Type material. Holotype: one adult male, Finland, Li Karigasneiemi, GE 1765, ykj: 770:345, 1973, leg. E. Jakkola. Paratypes: three males, Finland, Li Karigasneiemi, GE 1766, ykj: 770:345, 1973, leg . E . Jakkola; Finland, Sao Torasjoki, GE 1768, ykj: 676:348, 17 .IX .1983, leg . J . Hämäläinen; Finland, Le Pikku-Malla, GE 1767, ykj: 765:325, 16 . VII.1969, leg . B . Lindeberg.

Description. Male (n = 4). As described by Tuiskunen (1985). Additional characteristics and corrections:

Head ( Figure 1 (a)). Temporal setae with 2–3 outer verticals and 1–2 postorbitals. Frontal tubercle 6–7, 6 μm long. Tentorium 125–130, 128 μm long. Clypeus wider than long, 50– 58, 54 μm long and 132–133, 132 μm wide, bearing 8–12 setae (62–66 μm long). Third palpomere with sensilla coeloconica and two sensilla clavata anterodorsally.

Antenna ( Figure 1 (b)). AR 0.95–1.2.

Thorax. Scutellars 4. Humeral pit small and indistinct.

Wing ( Figure 1 (c)). 0.37–0.44, 0.41 mm wide. Costal extension 59 μm long. Anal vein about 2/3 rd of Cu.

Legs. Hind femur with keel. Hind comb with 15–26 spines. Pulvilli about ½ the length of claw. P1–3 BV = 2.4, 2.9, 2.8. P1–3 SV = 3.0, 4.8, 3.8. P1–3 BR = 2.2, 2.2, 3.0.

Hypopygium ( Figure 1 (d)) Anal point 18–36, 27 μm long. Phallapodeme 40–60, 52 μm long, transverse sternapodeme 91–99, 94 μm long. Gonocoxite 195–198, 196 μm long, gonostylus 70–72, 71 μm long, 2–4 megasetae (L1–2 = 13–16, 14 μm; 11–13, 12 μm), and 1 large and 2 smaller spines. HR 2.8, HV 3.4.

Female, pupa and larva. unknown

Distribution and Ecology. This species so far has only been reported from Denmark, Finland, Norway and probably from Russia (Republic of Sakha (Yakutia)). Larva of the species apparently inhabits both lotic and lentic habitats ( Tuiskunen 1985; Makarchenko et al. 2019).

Note on etymology. In its original description, Tuiskunen (1985), the etymology of this species is not provided. It is likely that species is named after the toothed gonostylus of the male, referring to megasetae and large spines of gonostylus.

Remarks. A detailed examination of type materials indicates that D. dentatus poses two megasetae of similar shape, structure (although slightly different size) distinguished from one large and few smaller true spines. We examined the gonostylus of the type specimens and made our assessment in accordance with the definition given by Saether and Sublette (1983) which indicate megaseta is the immovable non-true spine on apical section of the gonostylus.

Figures

Figure 1. Doncricotopus dentatus Tuiskunen, 1985, a-d adult male. a. Head; b. Antenna; c. Wing; d. Hypopygium.

Figure 4. Doncricotopus nunavummiuti sp. n., a-f adult female. a. Head; b. Wing, c. Genitalia, ventral view; d. Dorsomesal lobe; e. Ventrolateral lobe; f. Apodeme lobe; g. Genitalia, dorsal view.

Figure 5. Doncricotopus nunavummiuti sp. n., a-d pupa. a. Frons; b. Thorax; c. Thoracic horn; d. Abdominal tergites, anal lobes and genital sacs; e. Sternites IV–VI.

Figure 6. Doncricotopus nunavummiuti sp. n., a-f larva. a. Antenna; b. Labro-epipharyngeal region; c. Mandible; d. Mentum; e. Procercus; f. Claws of posterior parapods.

Figure 7. Coloration contrast of Doncricotopus head capsules. a-b, larva. a. Doncricotopus nunavummiuti, paratype; b. Doncricotopus bicaudatus, holotype.

Figure 8. Doncricotopus sp. a-d, larva. a. Antenna; b. Premandible; c. Mandible; d. Mentum.