Abundance and seasonality of insects in urban fragments of the Brazilian Cerrado

Abstract

Insects are important ecosystem agents, however, in general, a decline in the composition and abundance of these animals around the globe has been observed. In the urban environment, this characteristic has been more critical, due to the lack of diversity and quality of habitats in these environments, which feature fragmentation of habitats. Thus, processes that naturally affect the composition of animals in the environment can be observed, shaping the abundance of species in their environments, processes such as seasonality, especially in tropical regions, with well-defined rain and dry seasons. Thus, the aim of this work was to evaluate the seasonality and abundance of insects in urban fragments in the Cerrado, for this purpose four urban fragments were sampled in Campo Grande MS, during the months of January to December 2012 using Malaise traps. 26,890 individuals of 19 orders were collected, where the abundance of insect orders stands out Diptera, Hymenoptera, Coleoptera, Lepidoptera, Hemipetera and Trichoptera. A peak in general insect abundance was found in November, and there were significant differences over the months between different orders. However, no difference was found between the fragments, however, there was a trend towards changes in the diversity of orders related to the size of the fragments. The different strategies to deal with water stress well marked for the Cerrado is an important factor for the composition of the insect fauna of the domain and variations in the habitat, such as area size and phytosocionomic composition directly affect the orders found.

Keywords

• Brazilian savannah
• Coleoptera
• Diptera
• Habitat fragmentation
• Hymenoptera