Stempellinella sp. A

Ekrem, Torbjørn, 2007, A taxonomic revision of the genus Stempellinella (Diptera: Chironomidae), Journal of Natural History 41 (21 - 24), pp. 1367-1465 : 1452-1454

Stempellinella sp. A

Material examined

China: 2 Pex ( ZSM), Jilin Province, Dongbei, river at road half way between Songjiang and Erdobaihe, 12 June 1980, E. J. Fittkau; 1 Pex as previous, except at river by Songjiang .

Diagnostic characters

Stempellinella sp. A can be separated from other Stempellinella species by the following combination of characters: pupa with moderately developed, broadly conical cephalic tubercles; thoracic horn long and thin with numerous small chaetae scattered on middle one-third; thorax with scattered sculpturing dorsally; anterior dorsocentrals slightly longer than posterior dorsocentrals; point patches on tergite II small, starting just anterior to seta D5; tergite six with anterolateral shagreen patches in addition to large point patches; anal lobe with 19–20 taeniae.

Description

Pupa (n 5 3, unless otherwise stated). Total length 2.2–2.5, 2.3 mm; abdomen 1.6–1.8, 1.7 mm long. Colour of pupal exuviae pale brown with darker lateral margins on abdominal segments VII – VIII and anal lobe.

Cephalothorax ( Figure 31A, B ): cephalic tubercle moderately developed, broad conical, 18–30, 24 Mm long; frontal setae taeniate, 150–200, 170 Mm long; pedicel sheath tubercle absent. Thoracic horn 300–360, 320 Mm long, 15–24, 21 Mm wide with 4–5 Mm long chaetae scattered on middle one-third; precorneals taeniate, arranged in almost a row on obvious mound, ca 200 Mm long, anterior setae placed somewhat closer to each other; median antepronotal taeniate, two lateral antepronotals: one taeniate, one long sensillum basiconicum; two pairs of fine dorsocentrals, anterior pair 45–50 Mm long, posterior pair 30 Mm long. Area of fine sculpturing dorsally on thorax, a few stronger granules present along median suture line. Prealar tubercle well developed, wide; nose of wing sheath well developed.

Abdomen ( Figure 31C ): TII with small triangular posteriomedian point patches which start slightly anteriorly to seta D5; hook row 85–100, 92 Mm wide with 35–42, 38 hooks. TIII – VI with large, p -shaped point patches, patches on TVI smaller; TVI –IX with anterolateral patches of shagreen. Segment II with pedes spurii B; segment IV with pedes spurii A. Segment II with 2 D, 2 V, 3 L setae; segment III with 3 D, 3 V, 2 simple and 1 taeniate L setae; segment IV with 3 D, 3 V, 2 simple and 1 taeniate L setae; segment V with 3 D, 3 V, 3 taeniate L setae; segment VI – VII with 3 D, 3 V, 4 taeniate L setae, segment VIII with 1 D, 1 semi-taeniate V, 3 taeniate L setae; segment IX with 1 D seta on anal lobe, 19– 20 taeniate setae in anal fringe. One pair of O-setae present anteriorly on tergites II – VIII and anterolaterally on sternites II – VIII. Pleurae IV – V with small fields of weak shagreen. Posterolateral spur on segment VIII well developed.

Remarks

Stempellinella sp. A is recorded only from the Jilin Province in China. A formal name has not been given since only a few pupal exuviae are known, and it is uncertain if these correspond to an Asian Stempellinella species known only from the adult.

Figures

Figure 31. Stempellinella sp. A, pupa. (A) Frontal apotome; (B) thorax; (C) abdomen, dorsal view.