Comparative Evaluation of Sampling Methods for Insect Diversity and Guild Composition during Rice Reproductive Stage

Abstract

Paddy field ecosystems are dynamic environments that support diverse insect communities which play crucial ecological roles. These ecosystems provide habitats for wide range of insects including natural enemies, decomposers and pests. Monitoring insect diversity is essential for integrated pest management (IPM), but it remains challenging due to the complexity and heterogeneity of paddy field habitats. Despite the availability of various sampling methods, limited studies have systematically compared their efficiency in capturing insect diversity. Thus, this study aims to evaluate the effectiveness of different sampling techniques: bucket-light trap, sticky trap and sweep net, in assessing insect diversity in paddy field agroecosystems. The study was conducted during the reproductive stage of a single paddy cultivation season in Pekan Darat, Butterworth, Penang, Malaysia. The study captured a total of 86,742 insect individuals from 10 orders and 36 families during the rice reproductive stage. The bucket-light trap method recorded the highest number of captured species, comprising 10 orders and 31 families, followed by the sticky trap (seven orders, 18 families) and sweep net (six orders, 15 families). The family Micronectidae was the most abundant in bucket-light traps, while Cicadellidae and Chironomidae were most prevalent in the sticky traps and sweep nets, respectively. The sticky trap method yielded the highest Shannon-Wiener diversity index (2.248) and evenness index (0.778), whereas the bucket-light trap method recorded the highest species richness (Margalef Index: 2.64). These findings highlight the significance of employing multiple sampling techniques to capture a comprehensive representation of insect community structure in agricultural ecosystems, which can inform effective management strategies and biodiversity monitoring efforts.