S. Mahunka szerk.: Folia Entomologica Hungarica 34/2. (Budapest, 1981)

bristle: 0.40, apical scutellar 0.56 (in mm). We are convinced that this specimen represents an additional new species but we do not want to make a description on the basis of a single female in this species-group. Paralimosina sp. - 1 o: La Gomera, El Cedro, leg. H. FRANZ ("Sp 1308"). It belongs probably to one of the two new species from La Gomera but because of the poor state of preservation it cannot be identified unequivocally. DISCUSSION Six species of the newly discovered Paralimosina beckerigroup (all of them limited to a comparatively very small area, the Canary Is.) indicate that this group is probably much richer in species. Two recognized subgroups of more closely related species show at least two ancestral lines within the P. beckeri-group. The first subgroup with three species: beckeri, gomerensis, franzi, includes two brachypterous species, each endemic to different islands (La Gomera and fran

zi to Tenerife) and one macropterous species: P. beckeri (Duda). A rather similar situation is also with the second subgroup comprising two brachypterous species, of which P.pilifemorata is restricted to La Gomera and P. anaptera to Tenerife (the sixth, unnamed species is not taken in consideration, since its relationships cannot be understood from the single female). Thus, the ancestors of both subgroups had to be macropterous, easily dispersable forms like P. beckeri (Duda) in recent times. It is worth mentioning that a very similar reduction of venation of wing has evolved in both brachypterous species from La Gomera (i.e. in P. franzi and P. pil

i

femorata)

, apparently as a consequence of the so-called convergent evolution. However, this is not surprising; similar reductions of venation have already been described in other brachypterous species of clearly non-related sphaerocerid taxa. REFERENCES DUDA, O. (1918): Revision der europäischen Arten der Gattung Limosina Macquart (Dipteren). Abh. zool.-bot. Ges. Wien, 10.(1): 1-240 FREY, R. (1936) Die Dipterenfauna der Kanarischen Inseln und ihre Probleme. - Commentât.biol.

, 6(1): 1-237. HACKMAN, W. (1958): Borboridae. - In: Frey, R.: Kanarische Diptera brachycera p.p., von Hakan Lindberg gesammelt. Commentât.biol.

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4): 48-52. PAPP, L. (1973): Sphaeroceridae (Diptera) from Mongolia. - Acta zool. hung., 19(3-4): 369-425. PAPP, L. (1977): Sphaeroceridae (Diptera) from the Canary Islands. - Folia ent.

hung., S.N., 30(1): 123-127. ROHÁclsK, J. (1977): Revision of the Limosina fucata species-group, with descriptions of four new species (Diptera, Sphaeroceridae). - Acta ent.bohemoslov.

, 74(

6): 398-418. Authors' address: Dr. L. PAPP Zoological Department Hungarian Natural History Museum H-1088 Budapest Baross u. 13 HUNGARY Dr. J. ROHÁŐEK Entomologické oddëiem Slezského Muzea 746 01 Opava Vitëzného února 35 CZECHOSLOVAKIA