A comparison of macro-moth assemblages across three types of lowland forest in Fiji

Abstract

Although many studies have shown a relationship between forest type and quality on resident lepidopteran assemblages, there appears to be an absence of such studies in Paci c island countries. This study compared nocturnal macro-moth assemblages in a native rainforest, mixed forest and a plantation of exotic trees (mahogany) near Suva, Fiji Islands. Four nightly surveys (4 h from dusk) were performed in each forest type using a mercury vapour light. A total of 491 macro- moths belonging to 92 species in nine families were collected. No statistically signi cant differences in abundance, species richness and various diversity indices were observed across the different forest types. Endemic species were collected in all three locations, although signi cantly more endemic individuals were collected in the native forest compared to the exotic plantation. When examining species composition, ‘analysis of similarity’ (ANOSIM) and non-metric multidimensional scaling suggested that the faunas observed in the mixed forest and the exotic forest might be different, with the fauna in the native forest intermediate between these two. Although we found no major differences in the moth assemblages in these three sites, the results collected provide baseline data for future studies and comparisons with other localities. The results also reinforce previous ndings which demonstrate that exotic plantations and semi-degraded forests may still provide useful refuges for endemic insect species of conservation value.