Abundance, seasonality and parasitism of Diaspididae (Hemiptera) on olive trees

Abstract

Olive culture is a recent activity in Rio Grande do Sul, Brazil with little information on its scale insects. Abundance and seasonality of armored scale insects (Hemiptera, Diaspididae) and their parasitism was evaluated in olive orchard, Olea europaea L., cultivar Arbequina, in Caçapava do Sul (30°30′43″ S, 53°29′27″ W), RS, Brazil. Samples were monthly collected from April 2012 to March 2013. At each occasion 20 trees were drawn and, from each quadrant of their canopies (northern, southern, eastern and western) two branches (20 - 30 cm - length and contained at least 20 leaves) were randomly removed, respectively from the inner part and the outer part of the canopy. We found five species of Diaspididae, Aonidiella aurantii (Maskell), Hemiberlesia cyanophylli (Signoret), Acutaspis paulista (Hempel), Aspidiotus nerii Bouché and Melanaspis obscura (Comstock). It was not found an unique pattern of abundance, indicating that these species respond differently to temperature variations between seasons. The armored scale insects were evenly distributed among quadrants. Only H. cyanophylli showed differences in abundance between the inner and outer branches. We registered parasitism in all Diaspididae species; the total parasitism rate was 9.78%.