Sciarokeroplatinae, Papp & Ševčík, 2005

Papp, L. & Ševčík, J., 2005, Sciarokeroplatinae, A New Subfamily Of Keroplatidae (Diptera) *, Acta Zoologica Academiae Scientiarum Hungaricae 51 (2), pp. 113-123 : 120-122

Sciarokeroplatinae subfamilia nova

Type genus: Sciarokeroplatus L. PAPP et ŠEVČÍK

A subfamily of Keroplatidae .

Small anisoneuran flies with Sciaridae-like appearance but without eye-bridge or ocelli, 14-segmented flagellum, four-segmented palpi (in most Sciaridae three-segmented, but four-segmented in genera like Ohakunea and Colonomyia (see COLLESS 1963), and also in Heterotricha and allied genera (as CHANDLER (2002) wrote, “a short palpiger and three longer palpomeres”); wing venation similar to that of Keroplatidae (Cu2 distant from Cu1, A2 well developed) but with well-developed alula, and with well-developed pulvilli (and well-developed claws at the same time). Short coxae, especially of the mid and hind legs. Male genitalia are as simple as those of Cecidomyiidae (see SKUHRAVÁ 1997) and simpler than that of the Sciaridae (cf. MENZEL & MOHRIG (2000), a rich source of information on male genitalia of Sciaridae ). The structure of the head sclerites is unique, but comparable though much different from that of Macrocerinae . If we homologize the dorsal sclerite of the head with the cerebral sclerite of Macrocera , as given by MATILE (1990: figs 6–9, etc.), it keys to Macrocerinae in MATILE’ s (1990: 125) key to the subfamilies of Keroplatidae . However, we do not think that its inclusion in that subfamily would be correct.

Well-developed pulvilli must be a character in the groundplan (stem-species) of Sciaroidea. There are discernible pulvilli in Cecidomyiidae , in Sciaridae and in the Heterotricha group but there are also small but detectable pulvilli in Bolitophilidae . In our opinion the very small hairy structures in the species of Macrocerinae and Diadocidiidae are also true pulvilli. So if we are right, the loss of pulvilli in Sciaroidea must be a parallel process (in Ditomyiidae , in Keroplatidae , in Mycetophilidae + Lygistorrhinidae ). This conclusion, when related to the hypothesised tree of the Sciaroidea families (e.g. SØLI et al. 2000), is in complete congruence with previous conclusions based on many other characters.

Vein A2 is present in most genera of Keroplatidae , but weaker. A2 is similarly strong and a small alula present in Sylvicola and Olbiogaster ( Anisopodidae ). Again, A2 is rather strong in Mesochria and Mycetobia ( Mycetobiidae ), but neither of them have an alula. The well-developed alula of Sciarokeroplatus is very similar to that of some species in Bibionidae and Pleciidae . (cf. presence of alula in some “Oligoneura” from Upper Triassic: KRZEMIŃSKI (1992: figs 5b, 6b, 10b)).

We tried to identify Sciarokeroplatus to family through OOSTERBROEK’ s (1998) key, which is the best available key to the families of Oriental Diptera . We cannot find its relatives if we follow no. 8 (ocelli absent). If we follow the opposite alternative (no. 23: ocelli present), we can reach couplet 28 (discal cell absent, costa not continuous around wing) with some trouble at couplet 25: our fly has well-developed pulvilli and empodium, its antenna arises distinctly below the level of the centre of the eye, and it has no closed basal cell. We can reach Keroplatidae only, if we follow the statement that vein M3 (CuA1 of OOSTERBROEK) connected with stem of veins of M1 and M2, which is not the case of Sciarokeroplatus .

We encounter similar difficulties with PAPP and SCHUMANN’ s (2000) key: we have to follow the “Ocelli present… 23” branch at couplet 13. At couplet 37 the term “cubital fork” is misleading: it means M3 and Cu1. However, in Sciarokeroplatus base of M1+2 (even if we combine it with Rs) is not connected to M3. There is a shallow colourless area between them, which may be evaluated as “a memory of former connection” but it is definitely not a real connection. It is even more difficult to decide since adjacent section of M3 disappears. If we follow then no. 38, it runs to Macroceridae ( Macrocerinae ).

We did not try to make a cladistic analysis of Sciarokeroplatus here. Our main reason is that since we think of its closer relatives as fossils, there would have been difficult to make a reliable data matrix for all those taxa. The taxonomy of the higher (family group) taxa of Sciaroidea has been in rapid development. In the situation when that is still a question whether Heterotricha and the allied genera are offshoots of the stem group of Mycetophilidae or Sciaridae ( CHANDLER 2002) , our failure may be excusable, at least we hope so. It is a matter of course, that further studies are necessary in order to know the phyletic relations of Sciarokeroplatus .

*

Acknowledgements – We are grateful to Dr WOLFGANG SCHACHT (Zoologische Staatssammlung, München, Germany), to Mr. VIT KUBÁN (Moravian Museum, Brno, Czech Republic) and to Ms MEI-LING CHAN (Entomology, National Museum of Natural Science, Taichung, Taiwan) for loans of specimens. Dr. HANS-GEORG RUDZINSKI kindly informed us about the interesting specimens in the Sciaridae collection of ZSM.