Diversity and Seasonal Dynamics of Arthropods in Okomu Forest Reserve

Abstract

A field survey was conducted in Okomu Forest Reserve Edo State, to assess the diversity and seasonal dynamics of arthropod species in selected land use systems (Okomu national park, Okomu rubber plantation and Okomu oil palm plantation). Samplings of arthropods were carried out between February and September 2020, arthropods were collected by hand picking and sweep net in each sampled plots at 25 m x 25 m in the study area. Insects encountered were killed and preserved by chloroform. Arthropods samples were taken to the laboratory for oven dry and identification. A total of 382 arthropods spread across 15 orders, 34 families and 81 species were recorded. The most dominant orders were Hymenoptera (Ants) followed by Odonta (dragonfly) and Lepidoptera (butterfly and Moth) during dry season while highest abundance of orders were Spirostreptida (millepde) followed by Hymenoptera (Ants) and Araneae (spider) during rainy season. Okomu National Park has the highest (220) insect species abundance follow by Okomu Rubber Plantation (136) while the least was Okomu Oil Palm Plantation (72) in the study area. Study revealed that Okomu Rubber Plantation has no record of Scolopendromorphra (centipede) andHemiptera (bug) while in Okomu Oil Palm Plantation no record of Scolopendromorphra (centipede), lepidoptera (butterfly), also there were norecord of blattodea (crockroach) order of insect species in Okomu National Park. The highest species diversity and evenness was observed in Okomu National Park (H’ = 3.03 and E’= 0.83) follow by Okomu Oil Palm Plantation (H’=1.89 and E’=0.86) while Okomu Rubber Plantation was the least (H’ = 1.53 and E’= 0.60). ANOVA showed significant (P≤0.05) different on diversity and abundance between land use systems while there is nosignificant (P≥0.05) different seasons in the study area. Observation was made on seasonal variation of arthropods species in different land use systems and dominant species as bio-indicators in the study area.