Riethia, Kieffer, 1917

Cranston, Peter S., 2019, Riethia (Kieffer 1917) (Diptera: Chironomidae) revised for the Austro-Pacific region, Zootaxa 4646 (3), pp. 461-500 : 495

Riethia larva ‘B’

( Fig. 5H )

Material examined, larval head capsules only, AUSTRALIA, 2L., Queensland, nr Mareeba, Davies Ck., 17°01'S 145°35'E, 3.ix.2005 ( MV FNQ 7_6 (3i), MV FNQ7_8 (4i); 2L, Cloudy Ck., 18°59.50'S 146°12.30'E (Krosch) ( MV FNQCCR 3, 2).

New South Wales, 2L (1 3i, 1 4i, Clyde R., Brooman, 16.ii.2009; 2L, Currowan S.F., Cabbage Tree Ck., 35°34'S 150°02'E, 3.i.2009 ( MV AU09 CTCR14 , 15 ).

Four larvae form a clade based on molecular data, supported by ordinations of mensural data versus CO1 genetic data (N. Herold unpubl. obs.). Morphologically these resemble larvae of R. cinctipes in the characteristically thinned cuticle on one side of antennal segment 3, beside, and perhaps associated with, the Lauterborn organs ( Fig. 5H ). The major distinction is in antennal segment 4 being subequal to slightly shorter than the 2 nd (80–100%), whereas in cinctipes it is significantly and consistently shorter than the 2 nd (by c. 60%) (Table 2).

Larva type B is unreared, and cannot be associated due to sympatry with others.

Both molecular vouchers from Davies Ck. ( FNQ 7–6, FNQ7–8) are from Cranston et al. (2011) for Riethia species 3 and 4, separated morphologically due to earlier failure to recognize presence of 3 rd and 4 th instars of the same species.

Figures

FIGURE 5. Riethia spp. Larva. A. Dorsal head, R. cinctipes Freeman; B. Mentum, R. stictoptera Kieffer; C. Mandible, R. stictoptera. D-I. Antenna, D. R. azeylandica sp.n., E. R. cinctipes Freeman, F. R. donedwardi sp.n., G. R. neocaledonica sp.n., H. R. larval sp.’B’; I. R. stictoptera. Maxilla, J. R. neocaledonica, K. Pseudochironomus sp., L. Aedokritus coffeatus Trivinho- Strixino, M. Manoa pahayokeensis Jacobsen & Perry, N. putative Megacentron Freeman, O. Manoa obscura Fittkau.