Edaphic insect fauna associated with reforestation with Schizolobium parahyba Barneby in Amazonia

Abstract

Currently, little is known about the edaphic insect fauna associated with forest ecosystems with parica (Schizolobium parahyba var. Amazonicum) (Fabaceae) in the Brazilian Amazon Rainforest. The species presents great economic value to the timber market; however, insects with potential damage to this crop have been identified in periodic surveys. The purpose of this study was to evaluate, in commercial plantations of different ages in the dry and rainy seasons, the abundance and dominance of major functional groups of insects in forest ecosystems with parica. Collection was carried out using pitfall traps exposed for 24 h. Insect identification contemplated order and family. The results showed that the number of insects was directly related to the precipitation regime, because the total density of the insect fauna in the rainy season was 61\% higher than in the dry season. During the study period, 17,595 insects belonging to 11 orders and 37 families were captured. The order Hymenoptera was the most abundant in the dry season, representing 92.20\% of the individuals captured. The highest number of families (15) was found in the order Coleoptera. In the rainy season, the two and three year-old plantings showed greater richness of orders (9), but fewer families (22 and 21), respectively. Five-year-old plantings were the richest regarding families (26), mainly for being more stable environments. The most important functional groups were herbivores, predators, and social insects.