Weed Diversity and Associated Entomofauna in High-Andean Organic Pastures

Agroecosystems comprise various components, including weeds, insects, and microorganisms, which interact with one another and play distinct roles in achieving sustainable agriculture. This balance is essential for both agricultural productivity and environmental preservation. This study explores the relationship between diversity and ecological functions of weed species and the entomofauna present in a pasture under rotational grazing and organic management in Otavalo, Ecuador. Sampling was conducted over an area of 2.5 hectares. We identified and counted weeds using 65 quadrats, each measuring 4 m 2 . To capture insects, we employed chromatic traps, pitfall traps, and entomological nets. The results indicated a medium level of biodiversity, as shown by the Margalef index (4.85) and the Shannon–Wiener index (2.23), which also suggested a medium to dispersed evenness (Pielou_J = 0.23). Additionally, the ecosystem exhibited low species dominance, indicated by the Simpson index (D = 0.20). In total, we recorded 55 species belonging to 24 different botanical families. The most abundant families were Fabaceae (39%), Poaceae (21%), and Plantaginaceae (14.6%). For the entomofauna, a rich community was identified, comprising twelve orders and fifty families, with the order Diptera being predominant. Crucially, these findings demonstrate that agroecological practices foster a significant presence and diversity of both weed plants and associated insects, contributing to the agroecosystem’s resilience. We emphasize the role of diverse weed flora as refuges and resource providers for beneficial insects, such as those from the highly abundant Tachinidae family (Diptera), which are key natural regulators. This research highlights the importance of integrating weed conservation into pasture management for enhancing biodiversity, natural pest regulation, and promoting sustainable local transformation in highland agricultural landscapes.