Skusella, Freeman. There, 1961

Cranston, Peter S. & Tang, Hongqu, 2018, Skusella Freeman (Diptera: Chironomidae): new species, immature stages from Africa, Asia and Australia, and expanded distributions, Zootaxa 4450 (1), pp. 41-65 : 56-57

Skusella sp. ‘Jianfengling'

( Fig 4F, J )

Material examined. Pe (♀), slide mounted in Canada balsam, CHINA, Hainan [ Jianfengling NNR, drift sample from stream at approx. 1000m elevation], 23.v.1980 (Fittkau) ( ZSM) .

Description. Pupa (n = 1). 5.2 mm long. Exuviae pale brown with darker brown abdominal apophyses.

Cephalothorax. Cephalic area smooth with minute frontal setae arising from pale area of cuticle. Thorax smooth excepting oval patch of rounded scales in mid-thorax that may be associated with weak scutal ‘hump’. Base of thoracic horn elongate-oval, tracheal bundle sparsely packed, 17 x 19 µm. Without prealar tubercle.

Abdomen. Tergites II–VI with extensive spinulation, anteriorly filling area between apophyses and anteriorly extending to pleurae ( Fig. 4F ). Tergite II with row of 23 hooks extending 25% of tergite width. Pedes spurii B moderately developed, tapering, projecting ventrally rather than laterally (perhaps according to slide preparation). Pleural fringe on segment VIII only. Posterolateral ‘comb’ on VIII with 11 teeth diminishing in size from lateral to medial ( Fig. 4J ).

Comments. This unreared pupal exuviae from Jianfengling, Hainan, shares uniquely with Afrotropical S. pallidipes a pleural fringe restricted only to segment VIII. The pupal exuviae can be distinguished principally by the tergal spinulation on III–VII extending clearly onto the pleurae ( Fig. 4F ). In contrast in S. pallidipes all pleurae lack spinules in a much more restricted spinulation pattern ( Fig. 5B ).

Figures

FIGURE 4. Skusella pupae. A, Cephalic area in S. sp. ‘Limuling’; B, Lateral thorax, S. sp. ‘Limuling’; C, Base of thoracic horn, S. subvittata; D, Prealar tubercle, S. subvittata; E, Sternite I, S. sp. ‘Sanyatang’; F, Part of tergite IV, S. sp. ‘Jianfengling’; G, Segments II–IV with pedes spurii B and pleural fringe, S. subvittata; H–J Segment VIII posterolateral ‘combs’, H, S. subvittata; I, S. pallidipes, J, S. sp. ‘Jianfengling’.

FIGURE 5. Skusella pupae, abdomen (dorsal). A, S. subvittata; B, presumptive S. pallidipes; C, S. freemani.