Evaluation of the diversity and abundance of selected insect orders (Orthoptera, Hymenoptera and Coleoptera) in a wetland in Federal University Oye-Ekiti, Nigeria

Abstract

This study assessed the diversity and abundance of selected insect orders (Orthoptera, Hymenoptera and Coleoptera) in a wetland at Federal University Oye-Ekiti. Insects were collected from February to April, 2022 using a combination of pitfall traps, sweep nets and active hunting methods. Arthropods were identified up to the generic level and counted monthly. A total of 3654 individuals belonging to 3 orders, 21 families and 54 species were recorded from the studied habitat. The highest relative abundance of 19.37603% was found in Odontomachus monticola (Hymenoptera: Formicidae). In this study, Hymenoptera was the most dominant order while Orthoptera was the least dominant order. The active hunting method collected the highest number of insects while the sweep net method collected the lowest number of insects. Results of the percentage distribution of insect species and individual insects revealed that for both active hunting and pitfall trap methods, the Order Hymenoptera had the highest percentage distribution while the Order Coleoptera had the lowest percentage distribution. Results of the diversity index across the collection methods revealed that the Sweep net method had the highest insect diversity and evenness (H’=2.492, 0.4317) while the Pitfall method had the lowest insect diversity and evenness (H’=1.818, 0.126). Results of one- way ANOVA showed no significant difference in species composition across habitats at a 5% probability level. This study has shown that the etlandd at Federal University Oye- Ekiti is rich in insect species with the Order Hymenoptera being the most abundant.