Microtendipes robustus Song & Qi, 2023

Figs 7 B – E, 8

Microtendipes robustus Song & Qi, 2023: 16.

Material examined

(N = 3): 1 larva, China, Zhejiang Province, Lishui City, Qingyuan County, Baishanzu Town, 1370 m, 27.754°N, 119.186°E, 14. VIII. 2020, C. Song ; 1 larva, China, Zhejiang Province, Lishui City, Qingyuan County, Baishanzu Town, 1650 m a. s. l., 27.751°N, 119.199°E, 14. VIII. 2020, C. Song ; 1 larva, China, Zhejiang Province, Wenzhou City, Taishun County, Wuyanling National Nature Reserve, 1060 m a. s. l., 27.424°N, 119.404°E, 25. IX. 2020, C. Song ; 1 larva, China, Zhejiang Province, Wenzhou City, Taishun County, Wuyanling National Nature Reserve, 660 m a. s. l., 27.423°N, 119.404°E, 25. IX. 2020, C. Song .

Diagnosis

(Fig. 7 B, C). The larvae possess a light brown cephalic capsule and dark brown mentum, with the pale median teeth forming a distinct contrast against the darker lateral teeth.

Total length. 2.9–9.6 mm, 5.0 mm; head capsule length 325.0–650.0, 521.3 μm; head capsule width 287.5–620.0, 480.6 μm.

Mentum (Fig. 7 C). Width 92.5–185.0, 151.9 μm; median tooth width 20.5–42.5, 33.3 μm; ventromental plate width 75.0–150.0, 120.0 μm; distance between ventromental plates 51.0–125.0, 105.9 μm; number of striae 28–43, 38.3.

Mandible (Fig. 7 D). Length 115.0–200.0, 174.4 μm.

Antenna (Fig. 7 E). Segment lengths, 42.5–117.5, 75.8 μm; 15.5–25.0, 22.6 μm; 17.5–27.5, 21.9 μm; 15.0–18.0, 17.1 μm; 11.0–15.0, 12.9 μm; 5.0–8.0, 6.1 μm. Antennal ratio (AR) 0.8–1.3, 0.9. Ring organ width 20.0–37.0, 30.5 μm; ring organ positioned at 0.3–0.6, 0.4 of basal segment, 22.5–32.5, 26.3 μm from segment base.

Labrum. Premandible with two apical teeth; length 60.0–110.0, 90.0 μm. Pecten epipharyngis with three broad marginal teeth apically; labral lamella composed of 16–17 small teeth.

Thorax. Anterior claws pale with golden hints; posterior claws darker, pale brown. Procercus and apical setae are yellowish brown.

Abdomen. 8 tail hairs of anal seta, 347.0–602.3, 492.5 μm (Table 1).

Ecological environment

(Fig. 8). A mountain stream, fed by natural springs, meandering through forested terrain with a bedrock-dominated streambed and pristine water.

Remarks.

A comparative analysis was conducted between our data and the larval morphological measurements reported in Tang (2006). The larvae of M. robustus are similar to those of M. pedellus in mentum shape. However, M. robustus has a shorter overall body length (mean 5.0 mm vs. 8.8 mm in M. pedellus), shorter postmentum (mean 190.8 μm vs. 223.0 μm in M. pedellus), as well as a shorter mentum (mean 174.4 μm vs. 210.0 μm in M. pedellus) compared to M. pedellus .