Entomofaunal Assessment of Ecosystem Health and Suitability of Mangroves at Asarama, Andoni Local Government Area, Rives State, Nigeria

Abstract

Insects which inhabit mangroves at intertidal zones of the aquatic ecosystem contribute immensely to the wellbeing and sustainability of the mangrove ecosystem, and consequently are used to determine the ecosystem health of mangroves. Investigations on the diversity and abundance of insects to assess ecosystem health of mangroves at Asarama, Niger Delta, Nigeria were undertaken. Sweep nets and forceps were used to collect insects from three mangrove-type habitats; Rhizophora mangle (Red), Avicennia germinas (Black) Laguncularia racemosa (White). The insects were placed in sample vials containing 70% alcohol and taken to the Entomology Research Laboratory of the Department of animal and Environmental Biology, University of Port Harcourt, Nigeria, for sorting, and identification. A total of 24 taxa belonging to 7 orders and 15 families were collected during the study; red, black and white mangroves recorded 19, 14 and 7 taxa, respectively. Eight taxa Camnula pellucid, Jacobiasea formosana, Tettigonia caudate, Vespula vulgaris, Lucilia sericata, Pseudoleon superbus, Chrysocoris stolli, and Cordulia shurtleffi of the 19 that occurred on red were absent from black and white mangroves. Three species; Pieris rapae, Anopheles gambiae and Musca domestica, occurred across the three mangrove habitats. A total of 104 insects; 54 (red), 35 (black) and 15 (white) mangroves were recorded. In Asarama mangroves R.mangle is the most suitable habitat for insects species because it contained more entomofaunal diversity and abundance. The study revealed eight insect species that are indicators of good ecological health of the mangrove ecosystem, and used for the assessment of changes in the ecosystem.