Are aquatic insect species sensitive to banana plant cultivation?

Ephemeroptera, Plecoptera, Trichoptera and Coleoptera (EPTC) insect fauna were collected in ten streams located in the southeastern state of São Paulo (five located in areas with banana cultivation and five located in preserved areas). Specimens were collected during October and November 2005, using a Surber sampler and network D (0.25 mm mesh size) in areas of rapids and backwaters. The organisms collected were identified to genus level, except for some small or damaged specimens that remained at the family level. In total, 1812 individuals of EPTC were identified, in which 1105 organisms were from streams in areas of banana cultivation and 706 from streams in preserved areas. Heterelmis (Elmidae) was dominant in both sets of streams. In preserved streams, Hexacylloepus (Elmidae), Tupiperla and Paragrypopteryx (Gripopterygidae) and Nectopsyche (Leptoceridae) also had high participation. Leptonema (Hydropsychidae) and Xenelmis (Elmidae) were dominant in streams located in areas of banana cultivation. The analyses of indicator species point out to five taxa on preserved streams and two taxa in the banana streams. The forested streams had higher richness and diversity of EPTC than banana plantation streams. Correspondence analysis point for two groups, one gathered in the streams near the banana plantation and the other in the preserved streams. The similarity test (ANOSIM) pointed to significant differences (P < 0.05) between these groups. This agricultural activity seems to influence the EPTC community structure in low order streams in the Atlantic Forest region. The identification of groups at the EPTC genus level was important to point out the differences between the fauna of streams impacted by banana cultivation and to establish indicator species.