Studies on Some Life Table Parameters of Busseola fusca (Fuller) (Lepidoptera: Noctuidae) in Maize under Field Condition in Western Ethiopia

Abstract

Field Life Tables were constructed for Busseola fusca (Fuller) (Lepidoptera: Noctuidae) at Boneya and Haru during 2012 and 2013. The analysis of the life tables were done to determine the role of each factor such that density dependent factors (Predators and parasitoids) and density independent factors (wind) in the developmental stages of the insect. Meanwhile, key mortality factor was determined using Podoler and Rogers [1] regression method. The life table analyses showed that B. fusca has two generations per season at both locations. The highest population reduction of B. fusca was recorded at small larval stage which was caused by disappearance that could be due to predation and/or mobility to other plants or locations with the aid of wind in Boneya and Haru. Population reduction of small larvae and medium larvae caused by disappearance and/or migration were the key factor in changing the population of B. fusca in Boneya and Haru, respectively. The detection of density dependence result showed inverse density dependence between kparasitism of pupal stage and B. fusca population and no density dependence was detected for the other population reduction factors at Boneya. So the parasitoid couldn’t increase with the increasing population of B. fusca. At Haru the result was not significant for all population reduction factors, so there was no density dependence detected for all population reduction factors implying that population reduction factors acted irrespective of the population of B. fusca.