Preliminary Study of Insect Diversity and Its Economic Importance in Agulu-Nanka Gully Sites

The study was designed to investigate the insect diversity and its economic importance in Agulu and Nanka gully sites using standard procedures. A total of 1,609 insects belonging to 15 species were identified from the study sites, which comprised of 1026 individuals belonging to 15 species from Agulu and 583 specimens belonging to 8 species from Nanka. The diversity of the insect species highlighted the dominance, diversity index, species richness and species evenness. Blattodea were the most dominant order in both Agulu site (43.27%), and Nanka site (56.60%). The order Blattodea was the most diverse (0.725) in Nanka site, whereas the order Coleoptera was the most diverse (0.740) in Agulu site. Results from the economic importance revealed 8 insect species as harmful, 3 species as beneficial, while 4 insect species were considered as both beneficial and harmful. Beneficial insects are edible and good agents of pollination while the harmful insects devour agricultural produce and stored food. The result of this study shows that gully erosion site is dominated by insect diversity, probably due to the flora regeneration.