Population dynamics of the invasive species Zaprionus indianus (Gupta) (Diptera: Drosophilidae) in communities of drosophilids of Porto Alegre City, Southern of Brazil

Abstract

Dinâmica de Populações da Espécie Invasora Zaprionus indianus (Gupta) (Diptera: Drosophilidae) emComunidades de Drosofilídeos da Cidade de Porto Alegre, RS RESUMO -Estudos em populações de espécies invasoras permitem entender como os invasores reagem às novas condições bióticas e abióticas, e como espécies nativas reagem à invasão. Avaliou-se a eficiência de colonização da invasora Zaprionus indianus (Gupta), na área urbana da cidade de Porto Alegre, RS. Amostras de moscas foram tomadas de três parques urbanos, e índices ecológicos foram usados baseados na freqüência das espécies amostradas. Os índices foram calculados para sítios de oviposição e alimentação separadamente. A maior freqüência de Z. indianus comparada aos outros drosofilídeos foi registrada nas estações de temperaturas médias maiores, tanto para o componente sítio de alimentação como o de oviposição. Nessas mesmas estações, e para ambos os componentes, foram encontrados os maiores valores do índice de dominância (D) e os menores valores de diversidade (H'). Uma análise dos valores do índice de similaridade de Morisita mostrou que o Jardim Botânico e o Parque Farroupilha apresentam maior similaridade em termos de diversidade para o componente sítio de oviposição. Para o componente sítio de alimentação a maior similaridade foi entre Parque Farroupilha e Parque Gabriel Knijnik. Apesar de os três parques apresentarem algumas particularidades, a facilidade de estabelecimento de Z. indianus nesses locais parece ter sido a mesma. A chegada da invasora parece estar promovendo ajustes nas estratégias de sobrevivência das espécies residentes, pelo menos em certos períodos quando a freqüência das populações da invasora aumenta significantemente. Entretanto, pelo menos a maioria das espécies parece ter condições de coexistir com a invasora. PALAVRAS-CHAVE: Invasão biológica, índice ecológico, parque urbanoABSTRACT -Population studies of invasive species allow us to understand how invaders react to new biotic and abiotic conditions, and how native species react to invasion. We evaluated the colonisation efficiency of the invader Zaprionus indianus (Gupta), in the urban area of Porto Alegre city, southern of Brazil. Samples of flies were taken from three urban parks, and ecological indexes were used based on the frequency of the sampled species. The indexes were calculated for breeding and feeding sites separately. The highest frequencies of Z. indianus compared to the other drosophilids were registered during seasons of highest mean temperatures, both for the feeding and the breeding sites. The highest values for the dominance index (D) and the lowest values for diversity (H') were found at the same seasons and for both components. An analysis of the values for Morisita similarity index shows that the Botanical Garden and Farroupilha Park had higher similarity in terms of diversity of the breeding sites. For the feeding sites the highest similarity was between Farroupilha Park and Gabriel Knijnik Park. Despite the three parks have some particularities, the eas...

Assemblages of drosophilids (Diptera, Drosophilidae) in mangrove forests: community ecology and species diversity

“…II) suggests the homogeneity of the drosophilid assemblages in the mangroves of Santa Catarina Island. Additionally, the contribution of the seasonal variation found in the mangroves was very similar to that of the urban parks of Porto Alegre (SILVA et al, 2005), but lower than in other studies (SHORROCKS, 1975, in English forest;BENADO & BRNCIC, 1994, in Chile;DE TONI et al, 2007, in Atlantic Forest in Santa Catarina Island and vicinities). The annual variation contributed to a lesser extent, but relatively higher in the mangroves when compared with the studies above-mentioned (about half of the contribution of the seasonal component in the mangroves, compared with one fifth or less in the others).…”

Comparison of Drosophilidae (Diptera) assemblages from two highland Araucaria Forest fragments, with and without environmental conservation policies

“…Among the Neotropical indigenous species, the subgroup willistoni showed differences of more than 70% between areas (Table 3) Regarding the ecological indexes, PMA in 2006 (H' = 2.601) and the autumn in 2006 in both areas (PMA: H' = 2.941; FBL: H' = 2.626) had higher diversity than already detected, but in general, the diversity indexes (H') were mostly similar (but sometimes higher than) to those found in other works (Silva et al, 2005a;Tidon, 2006;Toni et al, 2007;Gottschalk et al, 2007;Bizzo et al, 2010;Schmitz et al, 2010;Poppe et al, 2012). No seasonal pattern was detected in both areas.…”

Taxonomic survey of Drosophilidae (Diptera) from mangrove forests of Santa Catarina Island, Southern Brazil

“…Soon after, the species was found in the southern states of Santa Catarina (De Toni et al 2001) and Rio Grande do Sul (Castro & Valente 2001), as well as in the Cerrado, Central Brazil (Tidon et al 2003), in the northern state of Pará (M. Martins, personal communication), and in Uruguay (Goñi et al 2001). In fact, this fl y became one of the most abundant species of drosophilids in open and disturbed areas (Tidon et al 2003, Silva et al 2005. In the present work, we collected 4,401 individuals of Z. indianus, about 5% of the total sample (Figs.…”

“…1 to 3). The abundance of this fl y in mangrove forests was higher than in the Atlantic Rain Forest, but lower than in the Cerrado (Tidon et al 2003) or in urban environments (Ferreira & Tidon 2005, Silva et al 2005. It is interesting to compare Z. indianus with D. simulans, the two most common species in urban areas of Santa Catarina Island (M. Gottschalk, personal communication).…”

“…The best-studied environment is the Atlantic Rain Forest, especially in the states of São Paulo (Dobzhansky & Pavan 1950, Val & Kaneshiro 1988, Medeiros & Klaczko 2004 and Rio Grande do Sul (Petersen 1960, Valente & Araújo 1991, Saavedra et al 1995. Drosophilids inhabiting urban environments were also studied in Olímpia, São Paulo, Brazil (Bélo & Gallo 1977, Bélo & Oliveira-Filho 1978, Bélo 1979) and later in Montevideo, Uruguay (Goñi et al 1997), in Porto Alegre, Rio Grande do Sul, Brazil (Silva et al 2005), and in Brasília, Distrito Federal, Brazil (Ferreira & Tidon 2005). In recent years, the Cerrado of Central Brazil has been site of investigations (Tidon-Sklorz et al 1994, Vilela & Mori 1999, Tidon 2006.…”