Economic injury level of citrus black-fly in commercial ‘Pera-Rio’ orange area

Abstract

Citrus black-fly (Aleurocanthus woglumi) has become an important pest in many citrus-producing regions in Brazil, causing direct and indirect damage to plants. Due to the lack of studies on the economic injury level (EIL) for this insect, control efficiency can be impaired. The objective of this research was to determine the EIL and the influence on the productivity of orange trees colonized by A. woglumi nymphs in an orchard located in the municipality of Capitao-Poço, Pará, using statistical analysis and damage prediction models through multivariate statistics. Population levels varied along the experiment. Infestation by A. woglumi nymphs negatively influenced orange production in Capitao-Poço with the highest population densities of the pest associated to lower plant productivity. The level of A. woglumi infestation on orange trees resulting in economic losses was, on average, 47.63% of infested plants, ranging from 22.75 to 89.92% and EIL is expressed by equation Y = 97.39 – 8.43x.