Polypedilum nubifer (Skuse)

Cranston, P. S., Ang, Y. C., Heyzer, A., Lim, R. B. H. & Wong, W. H., 2013, The Nuisance Midges (Diptera: Chironomidae) Of Singapore’S Pandan And Bedok Reservoirs, Raffles Bulletin of Zoology 61 (2), pp. 779-793 : 789-790

Polypedilum nubifer (Skuse)

Material examined. — ( Singapore material only cited). Many larvae, some pupae from Pandan, U. Pierce, Bedok, Poyan Reservoirs, Oct.2008, coll. NUS team including from colonisation experiments. Deposited ANIC, ZRC. Molecular vouchers: “Pnub”, Singapore, Pandan reservoir, between points 4 and 5, 6 Oct.2012, coll. Ang; CP28, 30, larvae, Pandan reservoir, between points 4 and 5, 18 Jul.2012, coll. Ang; ZRC .

Description. — Polypedilum nubifer has been described and illustrated adequately in all stages by, amongst others, Freeman (1961), Sasa & Sublette (1980), Chattopadhyay et al. (1988), Cranston & Judd (1989), and Cranston (2000, 2007).

To assist in recognition we provide images including habitus photographs of all stages: adult male ( Figs. 1–5 ), adult female ( Figs. 6, 7 ), egg masses ( Figs. 8, 9 ), pupae ( Figs. 12–15 ), and larvae ( Figs. 17–25 ).

A feature requiring consideration, and perhaps further study, is the apparent variation in the larval antenna. Variously described as 4, 5 or 6 segmented, the delimitation of segments is unclear. The Lauterborn organs, alternate and opposite on segment 2 (unique in the genus) can be considered apical on the two parts of a divided second segment, but the distinctness of division into 2 varies and can be difficult to verify. Equally, the number of segments distal to the apical Lauterborn organ seems to be three, but in some specimen preparations appears to be only two. Scanning electron microscopy by Sasa & Sublette (1980) helps, despite the external surface of the segment and the hyaline membrane between not differing in their reflection of electrons. Clearly from their fig. 27 there are 3 post apical Lauterborn organ segments, and the preceding segment (the 2 nd) has a break near the midpoint that should represent at least a weakened area in mid-segment.

Figures

Figs. 1–5. Midges as nuisance in Singapore. Polypedilum nubifer male: 1, habitus, lateral; 2, habitus, dorsal; 3, abdomen, dorsal; 4, hypopygium, dorsal; 5, anal point, superior volsella. Abbreviations: apt, anal point; gc, gonocoxite; gs, gonostylus; iv, inferior volsella; sv, superior volsella.

Figs. 6–11. Midges as nuisance in Singapore. Polypedilum nubifer female: 6, habitus, lateral, 7, habitus dorsal. P. nubifer eggs: 8, Egg masses; 9, solitary egg mass. Tanytarsus oscillans: 10, female habitus lateral; 11, eggs.

Figs. 12–16. Midges as nuisance in Singapore. Polypedilum nubifer pupa: 12, dorsal tergites; 13, frons; 14, base of thoracic horn, 15, posterolateral of tergite VIII. Tanytarsus oscillans pupa: 16, dorsal tergites.

Figs. 17–21. Midges as nuisance in Singapore. Polypedilum nubifer larva: 17, habitus; 18, lateral head; 19, ventral head; 20, mentum; 21, antenna. Abbreviations: bl, blade; LO, Lauterborn organ; m, mentum; vmp, ventromental plate.

Figs. 22–25. Midges as nuisance in Singapore. Polypedilum nubifer larva: 22, mentum; 23, mandible; 24, antenna; 25, anterior frons.