Microtendipes baishanzuensis Song & Qi, 2023

Jin, Haobo, Wang, Yiyi, Song, Chao & Qi, Xin, 2025, First morphological description of the larval stages of three Microtendipes species (Diptera, Chironomidae) from South China with molecular confirmation, ZooKeys 1255, pp. 27-40 : 27-40

Microtendipes baishanzuensis Song & Qi, 2023

Figs 3 B – E , 4

Microtendipes baishanzuensis Song & Qi, 2023: 8.

Material examined

( N = 2): 2 larvae, China, Zhejiang Province, Lishui City, Qingyuan County, Baishanzu Town , 1600 m a. s. l., 27.750°N, 119.198°E, 14. VIII. 2020, C. Song .

Diagnosis

(Fig. 3 B, C ). Mentum dark brown, with median teeth distinctly paler than lateral teeth; cephalic capsule brown. Total length 7.1–7.8, 7.5 mm; head capsule length 490.0–520.0, 505.0 μm; head capsule width 450.0–460.0, 455.0 μm.

Mentum (Fig. 3 C ). Width 152.5 μm; median tooth width 37.5 μm; ventromental plate width 125.0–132.5, 128.8 μm; distance between ventromental plates 83.0–90.0, 86.5 μm; striae count 35.0–40.0, 37.5.

Mandible (Fig. 3 D ). Length 168.0–195.0, 181.5 μm.

Antenna (Fig. 3 E ). Segment lengths, 102.5–112.5, 107.5 μm; 25.0–27.5, 26.3 μm; 27.0 μm; 25.0 μm; 17.0–17.5, 17.3 μm; 10.0 μm. Antennal ratio ( AR) 1.0–1.1, 1.0. Ring organ width 34.0–35.0, 34.5 μm; ring organ positioned at 0.2–0.3, 0.3 of basal segment length, 22.5–35.0, 28.8 μm from segment base; antennal blade 106.0–125.0, 115.5 μm in length, width 2.0–18.0 μm.

Labrum. Premandible with two apical teeth; length 97.5–120.0, 108.8 μm. Pecten epipharyngis with three broad marginal teeth apically; labral lamella composed of 15 small teeth.

Thorax. Anterior claws pale with a little golden posterior claws pale golden, both simple and dense.

Abdomen. 8 tail hairs of anal seta, 520.0–611.0, 565.5 μm (Table 1 ).

Ecological environment

(Fig. 4 ). A forest stream, winding through wooded areas, exhibiting high-clarity water flowing over a predominantly rocky substrate.

Remarks.

A comparative analysis was conducted between our data and the larval morphological measurements reported by Tang (2006). The larvae of M. baishanzuensis resemble Microtendipes pedellus (De Geer, 1929) and Microtendipes chloris (Meigen, 1933) in the shape of the mentum. However, M. baishanzuensis has more striae than M. pedellus (mean 37.5 vs. 30.0). The total length of the postmentum in M. baishanzuensis is shorter than in M. pedellus (mean 201.3 μm vs. 223.0 μm). The ring organ in M. baishanzuensis is located at 0.2–0.3 (mean 0.267) of the basal segment, compared to approximately 0.33. Compared to M. chloris , M. baishanzuensis has a distinctly shorter blade (mean 115.5 μm vs. 145.0 μm), a longer postmentum (mean 201.3 μm vs. 215.0 μm), and more striae (mean 37.5 vs. 28.0).

Figures

Figure 3. Larva of Microtendipes baishanzuensis Song & Qi, 2023. A. Habitus of larva; B. Head capsule; C. Mentum; D. Mandible; E. Antenna.

Figure 4. Habitat of Microtendipes baishanzuensis larvae.