Competition and Overlap of Ephestia kuehniella and Plodia interpunctella Moth Populations in Date fruits nutrition condition

Plodia interpunctella and Ephestia kuehniella are found in food storages, including dates palm. The aim of this study was to determine the competition and overlap of date moths. Three glass boxes with dimensions of 50 × 50 × 40 cm were designed for the experiments. There were 9 holes on the boxes body for sampling. Population changes of the two species were monitored in the storage conditions during 24 weeks. Time series models were used to study species populations and logistic growth model to estimate the effect of density of one species on another. The results showed that the environmental capacity of E. kuehniella and P. interpunctella were 2430 and 1610 and the population growth rate (r) were 1.2 and 1.3, respectively. The species population balances were close together from first to third week. The population of E. kuehniella decreased at the fourth week. The highest population balance of the two species was in the 13th week the potential of exploitable ecological nests (eij) and the number of ecological nests exploited by any species (zij) for E. kuehniella was higher than P. interpunctella from 8th week until the end of the sampling period. The overlap of ecological nests of the two species (D) ranged from 0.97 to 0.97, indicating complete overlap of temporal activity of the two moth species populations on date palm feeding conditions. The results of this study, along with other ecological studies of the date stored pest insect community, can be used by integrated pest management experts.