Diversity of insects associated with quinoa (Chenopodium quinoa Willd.) along an altitudinal gradient in Chimborazo, Ecuador

Abstract

Introduction: Quinoa (Chenopodium quinoa Willd.) is cultivated across extensive altitudinal gradients in the Andean region of Ecuador, where environmental conditions and the crop's phenology influence the dynamics of the associated insect communities. However, in Ecuador, there is still limited research that comprehensively examines the combined effects of altitude and phenology on the structure of these communities within organic farming systems. Objective: to analyze how the altitudinal gradient and the phenological stages of quinoa affect the abundance, diversity, and functional composition of insects in the Chimborazo province. Methodology: twenty-two sites were sampled, distributed across three altitudinal zones (3156 to 3526 meters above sea level) over four phenological stages of the crop. Patterns of abundance, species richness, and functional roles were assessed, and community composition similarities were analyzed using cluster analysis and a heatmap based on the dominant insect families. Results: a total of 4041 individuals from various orders and families were collected, categorized according to their functional roles. The intermediate zone concentrated on the highest abundance and exhibited the greatest diversity values, while the high-altitude zone had less diverse communities with greater relative dominance. Throughout the crop cycle, the flowering and physiological maturity stages showed the highest levels of abundance and functional diversity, with notable coexistence of phytophagous insects and natural enemies. In contrast, the milky grain stage displayed a temporary decline in entomological activity. Conclusion: these results demonstrate that altitude and phenology serve as key structural factors in the insect community and provide ecological insights for designing integrated pest management strategies tailored to each altitudinal zone and crop stage. General Area of Study: Agriculture. Specific area of study: Plant Health. Type of study: Original articles.