Orthocladius nitidoscutellatus Lundstroem , 1915

Ge, Xinyu, Wang, Chengyan, Pei, Wenxuan, Tang, Yaning, Liu, Wenbin & Yan, Chuncai, 2024, New descriptions of the larval and pupal stages of Orthocladius nitidoscutellatus and Psectrocladius nevalis from Xizang, China (Diptera, Chironomidae), Biodiversity Data Journal 12, pp. 121952-121952 : 121952

Orthocladius nitidoscutellatus Lundstroem, 1915

Orthocladius nitidoscutellatus Orthocladius nitidoscutellatus Lundström, 1915- Lundström (1915):11

Orthocladius nitidoscutellatus Orthocladius trigonolabis Edwards, 1924 - Edwards (1924): 170

Orthocladius nitidoscutellatus Orthocladius aquilonaris Goetghebuer, 1940 - Goetghebuer (1940): 63

Orthocladius nitidoscutellatus Orthocladius nitidoscutellatus Lundström, 1915 - Sæther (2004): 14; Ashe and O'Connor (2012): 434; Rossaro et al. (2022): 8

Materials

Type status: Other material. Occurrence: lifeStage: 1 Larva, 1 Pupa; occurrenceID: B6A08146-047E-5C20-8B5C-A354B2AED520; Location: country: China; stateProvince: Xizang Autonomous Region ; locality: Naqu City , Sena District , Naqu Bridge on the Naqu River , ; verbatimLatitude: 31°42.78′N; verbatimLongitude: 91°98.82′E; Event : eventDate: 7 Jul 2022; Record Level: institutionCode: Tianjin Normal University, Tianjin, China (TJNU)

Description

Pupa (n = 1).

Cephalothorax (Fig. 1 C, Fig. 2 C-D). Cephalic tubercles and frontal setae absent. Thoracic horn elongated, 429.62 μm long, 35.25 μm wide. Thorax smooth, free of tubercles. Wing sheath without protrusions. Next to the thoracic horn, three precorneal setae are present, lengths of precorneals (µm): 32.50, 72.40, 91.10. Four dorsocentral setae, lengths of dorsocentrals (µm): 120.18, 145.20, 150.25, 48.50.

Abdomen (Fig. 1 A-B, Fig. 2 E-F). Sternites I- II bare; Posterior row of hooks, extending nearly on 2/3 the width of tergite II; Sternites III-VI with posteromedian shagreen composed of large spines; Sternites VII-VII and anterior row of anal lobe with shagreen composed of fine spines. Pedes spurii A present in segment IV-VI. Pedes spurii B present on segment II. These are teeth at the distal margin of the anal macrosetae. Tergite I with 1 Lt-setae; tergites II-VI with 2 Lt-setae. tergite VII with 3 Lt-setae. Tergite VIII with 5 Lt-setae. Anal lobe 240.74 µm long and 246 µm wide, with 3 subequal anal macrosetae. Anal lobe genital sheath 111.12 µm long, non-extending anal lobe.

Fourth instar larva (n = 1).

Head capsule (Fig. 1 E) length / width: 294.69 µm / 304.13 µm: 0.97.

Colouration. Head capsule brown, mentum and the apical part of mandible dark brown; posterior occipital margin brown. Antenna (Fig. 1 D, Fig. 2 B) with each segments length (μm): 43.06, 11.45, 5.55, 4.46, 2.65. AR 1.79. Basal segment 16.59 μm wide, the basal segment length 2.60 times the width; the distance from base to ring organ 15.3 μm. Premandible 51.14 μm long, terminating in a single tooth. Mandible (Fig. 1 F, Fig. 2 A) 122 μm long, with 1 apical and 3 visible inner teeth, apical tooth 14.29 μm long, three inner teeth 23.74 μm wide; the outer margin smooth. Mentum (Fig. 1 F, Fig. 2 A) 1 median tooth and 12 pairs of lateral teeth, median tooth 21.65 μm wide, about 3.27 times larger than the first lateral tooth; mentum 113.3 μm wide; postmentum 130.1 μm long; the distance between the setae submenti 42.41 μm, the setae submenti slightly behind mentum. Abdomen have 4 anal tubules: 2 dorsal and 2 ventral ones. Segments I-VIII are rather similar in shape being quite symmetrical. Segment IX has the dorsal margin longer than the ventral margin, the dorsal margin carrying the procercus. Segment X is short, the posterior pseudopods being attached to its distal margin.

Figures

Figure 1. Orthocladius nitidoscutellatus Lundstroem, 1915. A pharate adult with pupae Chironomidae exuviae; B sternites VIII-IX; C wing sheath; D antenna; E Larval head shell; F mentum and mandible.

Figure 2. Orthocladius nitidoscutellatus Lundstroem, 1915. A mentum; B antenna; C frontal apotome; D thoracic horn; E sternites VIII-IX; F segment I-VII.