Drosophila Fallén, 1823

Hochmüller, Cleverton J. C., Lopes-Da-Silva, Marcelo, Valente, Vera L. S. & Schmitz, Hermes J., 2010, The Drosophilid Fauna (Diptera, Drosophilidae) Of The Transition Between The Pampa And Atlantic Forest Biomes In The State Of Rio Grande Do Sul, Southern Brazil: First Records, Papéis Avulsos de Zoologia 50 (19), pp. 285-295 : 292-293

Subgenus Drosophila Fallén

This is the largest subgenus of Drosophila . Twenty-eight species from 11 species groups were found, representing 41.5% of the specimens.

Drosophila annulimana group – This group comprises species endemic to Neotropical region found preferentially in wet forests ( Tosi & Pereira, 1993). Drosophila arassari was found in both collection sites, with one single individual in the urban area (Vila Rocha) and 23 individuals in the forest ( CEPPA), most of which in winter. The only species of the D. annulimana group recorded in Rio Grande do Sul before were D. schineri Pereira & Vilela ( Loreto et al., 1998) and D. annulimana ( Garcia et al., 2008) .

Drosophila bromeliae group – This is a small group of flower-breeding species, rarely attracted to banana baits. One individual of an undescribed species was found in CEPPA. This species, here referred to as D. type IV, had previously been found by one of us ( HJS) in Porto Alegre, RS .

Drosophila canalinea group – Only one female specimen was collected, in Vila Rocha, here denominated D. sp.13. We could not determine the species of this individual, but there is no previous record of this group in Rio Grande do Sul ( Gottschalk et al., 2008). Further collections of male specimens are necessary to confirm which species of the group are represented in the state .

Drosophila cardini group – This group consists of 15 Neotropical species, six of which present in Brazil, all from Drosophila cardini subgroup ( Gottschalk et al., 2008). In the present study, two of them were collected in both sites. Drosophila cardini Sturtevant , associated with open environments ( Tidon, 2006), were more abundant in Vila Rocha, while D. polymorpha , a species relatively abundant in different morphoclimatic domains in Brazil ( Sene et al., 1980), showed an opposite pattern, being the third most abundant species in CEPPA, reaching about 10% of the sample in that site.

Drosophila coffeata group – This small and poorly known group is formed only by four Neotropical species, three of which recorded in Brazil ( Gottschalk et al., 2008). One species of this group was collected, represented by one single individual of D. fuscolineata in CEPPA, representing the new southernmost locality of its known distribution. One single species of this group were recorded in Rio Grande do Sul before, D. pagliolii Cordeiro ( Cordeiro, 1963) .

Drosophila guarani group – Two species were found: D. maculifrons ( D. guaramunu subgroup) and D. ornatifrons ( D. guarani subgroup). Both were more abundant in the forest ( CEPPA) during winter and spring. They were, respectively, the second and fourth most abundant species in the forest fragment ( CEPPA), totaling 12.4% and 3.5% of the sample in that site, respectively.

Drosophila immigrans group – It is a large Oriental group, with D. immigrans reaching cosmopolitan status. It was found in both collection sites, but mainly in the urban area. During winter and spring it was collected at relatively higher numbers, also in the forest fragment ( CEPPA).

Drosophila pallidipennis group – One single-species group, constituted only by the Neotropical species D. pallidipennis . It was found in both collection sites and was the most abundant Neotropical species in Vila Rocha, though it did not reach 1% of the sample. In CEPPA, it occurred especially during winter and spring.

Drosophila repleta group – The largest Neotropical group of Drosophila , eight species from five subgroups were found in Cruz Alta. The three species of D. fasciola subgroup were found exclusively in the forest, especially during winter and spring. The collection site adopted in the present study is the new southernmost locality for D. papei and D. senei . The other species of the subgroup found was D. onca Dobzhansky & Pavan. The species of the D. mulleri subgroup, D. buzzatii Patterson & Wheeler and D. nigricruria , occurred in both sites. The most abundant species of the group were D. mercatorum Patterson & Mainland ( D. mercatorum subgroup), collected especially in CEPPA. The other two species were found in low numbers, D. hydei Sturtevant ( D. hydei subgroup) in CEPPA and D. zottii Vilela ( D. repleta subgroup) in Vila Rocha.

Drosophila tripunctata group – With 10 species found, this was the most diverse group of our collections. Most species were found exclusively in the forest, with higher abundances during winter and spring. Drosophila mediopunctata was the only species to occur in both sites, but with abundances considerably higher in the forest, where it was the fifth most abundant species. Drosophila mediostriata Duda and D. sp.14 were found exclusively at Vila Rocha, but one single individual for each. The remaining species, D. bandeirantorum Dobzhansky & Pavan , D. mediopicta Frota-Pessoa , D. nappae Vilela, Valente & Bassoda-Silva , D. paraguayensis Duda , D. roehrae Pipkin & Heed and D. trifilum , were exclusive from CEPPA. The collection of D. trifilum in Cruz Alta, as well as some collections in Porto Alegre (Carolina F. Garcia, not published), represents the first record of the species in the state. Drosophila sp. 14 is probably an undescribed species, and is the same referred as D. sp.tp.5 by Döge et al. (2008), from Joinville, Santa Catarina.

Drosophila virilis group – A small Palearctic group that includes the cosmopolitan D. virilis . One single individual was caught in Vila Rocha, what represents the first record of the group and the species in Rio Grande do Sul.