Comparison of Three Sampling Methods for Estimating Grasshopper (Orthoptera, Acrididea) Assemblages in African Rainforests

Abstract

Grasshoppers are essential components of terrestrial ecosystems, playing major roles in biodiversity and ecological balance. Assessing grasshopper diversity in specific regions is crucial for understanding species coexistence, supporting sustainable agriculture, and informing conservation efforts. Reliable and standardized survey methods are fundamental to this field. Sweep net sampling is widely recognized as the fastest and most commonly used method globally. This study presents the comparative assessment of three sampling methods for estimating grasshopper assemblages in African rainforests: 30 min of random net sweeping, 1 m 2 open quadrat sampling, and pitfall trapping. These methods were evaluated across two distinct ecological zones, fallow land, and forest. Results show that net sampling is the most effective method for estimating grasshopper diversity in these environments. However, incorporating quadrat sampling and pitfall trapping enhances species diversity assessment. Net sweeping is particularly efficient for collecting winged species in short vegetation, while quadrat sampling and pitfall trapping are better suited for species dwelling in the undergrowth and forest litter. A combine approach incorporating multiple sampling methods provides a more comprehensive assessment of grasshopper diversity, overcoming the limitations of sweeping alone.