Richness and abundance of the cardini group of Drosophila (Diptera, Drosophilidae) in the Caatinga and Atlantic Forest biomes in northeastern Brazil.

Brazil has a high diversity of flies of the genus Drosophila, and part of this richness is represented by the cardini group. We analyzed the fluctuations in the richness and abundance of this group, in environments that had never previously been studied in the northeastern region of Brazil. Among the 28,204 drosophilids sampled, 1,294 belonged to the cardini group and were represented by D. polymorpha, D. cardini, D. neocardini and D. cardinoides. Occurrences of D. neocardini and D. cardinoides were registered for the first time in the Caatinga. In this biome, D. cardini stood out as having the highest abundance, and D. polymorpha was not observed. In the coastal Atlantic Forest, D. cardini was not registered, but D. polymorpha was found in all the localities investigated. Mangrove swamps were the environment with the lowest abundance and richness of the cardini group. The High-altitude Forest presented the highest richness of this group. We suggest that the high abundance of D. polymorpha in the High-altitude Forest and in the coastal Atlantic Forest may be a reflection of the historical relationship between these two environments.