Diversity and abundance of insects in crystal guava plants (Psidium guajava L.) in North Sumatra, Indonesia

This study aims to determine the types of insects and the level of diversity, dominance, frequency of presence and evenness of insects on crystal guava plants in Hamlet I, Suka Makmur Village, Kutalimbaru District. This study aims to determine the types of insects and the level of diversity, dominance, frequency of presence and evenness of insects on crystal guava plants in Hamlet I, Suka Makmur Village, Kutalimbaru District. This study was conducted from April to May 2025 using yellow sticky traps (stationary) with four replications. The results showed that there were 28 insect species, 21 families and 8 orders with Bactrocera dorsalis and Bactrocera carambolae being the most abundant species. The insect diversity index was low (H' = 0.93). The dominance index was in the high category (C = 0.644). The frequency of presence was in the rare category (FP = 49.29%). The evenness index was in the low category (E = 0.2791). This study indicates an imbalance in the ecosystem because although the number of species is quite high, the distribution of the number of individuals between species is very uneven. The low H' value in this study indicates the need for habitat management and control of dominant species to create a more balanced and stable insect community and create environmental conditions that better support insect diversity and reduce pest dominance.