Diversity and Abundance of Insects Species in Makurdi, Benue State, Nigeria

Stephanie Mdzuami Adelusi, Raymond Tersoo Ada, Edward Agbo Omudu

Insects are unique in their own way and contributes all types of services to the ecosystem. In order to develop effective global insects’ conservation strategies there is the need to target species at local or regional scales. The current study was therefore designed for the very first time to document the diversity and abundance of insects in Makurdi, Benue State, Nigeria. Five sites reflecting different levels of disturbances and different land use covers were selected within Makurdi metropolis: Hudco Quarters North Bank (HQN), Benue State University Zoological Garden (BZG), Gyado Villa (GYV), High Level (HLV) and Akpehe (APH). Insects were collected from the months of October to November 2017. Three methods of insect collection were used; Pitfall method, Sweep net method and Hand Picking. Diversity indices were measured at each site using Simpson’s, Shannon, Menhinick’s and Margalef’s indices, while similarity between sites and trapping methods was assessed using Sorensen’s similarity index. There was no significant difference in the diversity of insect species between sites (F (4, 50) =0.000375, P>0.05), However, GYV had the highest diversity index and Species Richness (d) but lowest dominance Index, while, APH had lowest species richness and highest dominance. When the indices were converted to Shannon Effective number of species (ENS) to show the true diversity, GYV had the highest value for ENS while BZG had a lowest value. This is an indication of dominance because where there is a high degree of dominance; the ENS value will be less than the species richness. The Order Odonata was the most dominant and it occurred at BZG than all the other sites. Sorensen’s similarity index between sites was from 89% to 100%, an indication that all insects can occur at all sites. There was a significant difference between the trapping methods (F (2, 17) = 6.7965, P<0.05) with the sweep net having the highest average catch. However the similarity between trapping methods was approximately 67% between sweep net and pitfall while it was 53% between hand collection and sweep netting. This difference in the trapping method possibly accounted for the high numbers of winged insects in the collection. The ENS of the area was 7, this is low, but also an indication that more effort should be channeled into insect monitoring and conservation.