Characterization of Insect–Pollinator Biodiversity in Agrochemical-Contaminated Agricultural Habitats

Abstract

The extensive application of agrochemicals in agricultural habitats in the Southern Highlands of Tanzania (SHOT) is supposed to negatively impact the biodiversity community of insect–pollinators (INPOs). However, in light of existing knowledge, there are no studies to back up this claim. We carried out field surveys in the SHOT to assess and characterize the INPO biodiversity community in agricultural habitats and compare it with protected habitats. Direct observations, transect counts, sweep netting, and pan trap techniques were used for sampling the INPOs. Overall, the INPOs’ relative abundance (57.14%) and species diversity index in protected habitats were significantly higher compared to agricultural habitats. Similarly, we recorded a higher number of plant–INPO interactions in protected habitats than agricultural habitats. Our results suggest that, in contrast to protected habitats, agrochemicals might have driven out or discouraged INPOs from agricultural habitats, resulting in dwindling species richness, diversity, and abundance. This could be due to agrochemical contamination that impairs the quantity and quality of floral resources (nectar and pollen) required by INPOs. Alternatively, protected habitats seemed healthy and devoid of agrochemical contamination, which attracted many INPOs for foraging and nesting. Thus, in order to maintain healthy agricultural habitats and support INPO biodiversity, conservation agriculture is imperative.