ABSTRACT

This study was conducted to investigate the effects of seasonal changes on distribution and abundance of insects in three habitat types in Umudike Area, of Abia State, Nigeria. The specific objectives were to: to investigate the seasonal changes in insect diversity of three habitat types in Umudike Area, Abia State, to compare the abundance of selected key insect species during the wet and dry seasons in three habitat types, to determine the status and distribution of different insect groups in the study sites, to generate baseline data for kick-starting long-term monitoring of the insect's life of the area. Insects sample were collected weekly from each sampling sites using locally made sweep net, picking was done with hands or forceps. Data were collected for five months with two months wet season (June and July) two months dry season (November and December) and period one month as transition (April) 2018. The results obtained were presented using descriptive statistics such as graphs, tables and chats. A total of 1264 insects spread across nine (9) orders, twenty-eight (28) families and forty-three (43) species were recorded. The different insects sampled, were higher during the wet season as compared to the dry season. Although insect species were significantly most abundant in the Fish farm site followed by the Experimental farm site. Relict forest had the least abundance. Shannon diversity index suggested that insect diversity was highest in Relict forest during the wet season. Species evenness based on the pielou' s index suggested high spread of the species across the habitat types and seasons. In Relict forest, the most abundant insects order is Hymenoptera. Meanwhile, Odonata (damselflies and dragonflies) were most abundant in Fish farm site. While Orthoptera were most abundant in Experimental farm site. In all the three habitat types sampled Orthoptera were most abundant insects order. Meanwhile among the insect families recorded Acrididae was most abundant. Insect species were most abundant at the relative humidity between 93 —97% and at temperature of 27°C but least at relative humidity between 88 — 92% and at temperature of 29°C. Comparing species composition among the surveyed habitat types revealed that insect species assemblages were very similar between the wet and dry seasons in Relict forest and the Fish farm site. The study concluded that there were high spreads of insect species across the surveyed habitats. The study recommended that routine insect abundance and diversity monitoring should be encouraged.