Ecological aspects of edaphic grubs (Coleoptera: Scarabaeoidea: Melolonthidae) in tropical forested and intervened ecosystems of the Northeast Colombian Andes

Abstract

Objective. To establish the variation of the diversity, density and biomass of white grubs of the Melolonthidae family in soils affected by mining and in the soil of an oak forest in the upper basin of the Surata river (Santander, Colombia). Scope. To analyse the diversity, density and biomass of the immature stages of beetles (Coleoptera: Melolonthidae) on two soil uses: recovered gold exploration platforms and an oak forest. Methodology. Monthly quadrantsof 1 m2 by 30 cm deep were made throughout 12 months of sampling. The area of study is located in the northeast Colombian Andes, between 2,300 and 2,950 meters above sea level. Correlations were established between the measured parameters (abundance, richness of species, biomass, density and numbers of Hill) and biophysical factors of the study area. Main results. The highest values were observed in the oak forest: 12 species, 6.16 gr/m2 and density 4.08 ind/m2. However, only the biomass values were statistically significant (Z= 2.903; p= 0.004). Significant correlations were observed between abundance, density and biomass with the lowest humidity in the platforms but not in the oak forest. The maximum values of abundance, density and biomass coincided with the rainy season, and the highest values of diversity occur at the end of the dry seasons. Conclusions. The data obtained in thishigh mountain ecosystem show interesting variations in abundance and richness, which can be explained by the presence of a wide and extensive matrix of oak forest that allows the permanence of species of white grubs and relatively well-preserved natural populations.