Impact of weeds on Auchenorrhyncha incidence and species richness in citrus orchards

Abstract

Due to the risk posed by the imminent invasion of Xylella fastidiosa in Mediterranean countries, scientific focus has shifted towards studies on the ecology of the bacteria’s potential vectors belonging to the Auchenorrhyncha suborder. In order to gain knowledge regarding the management of this pest,it is essential to evaluate the potential impact of Auchenorrhyncha weed hosts and their population composition on the ecology of these species. Under this light, the relationship between Auchenorrhyncha species abundance and composition and wild plant species of a citrus orchard in central Greece (Attica) was studied. The orchard was divided in two sections based on weed management treatments: one with weeds being removed by mowing and the other without any weed treatment. Yellow sticky traps, replaced in a weekly basis, were installed in each orchard section while a migration Malaise trap was installed in the border of the two sections. Additional sampling from different weed species and citrus trees using an entomological net was carried out weekly. Results showed that the presence of weeds (especially those belonging to the Poaceae family), affected both auchenorrhynchan insect diversity and population levels. A marked preference of insects for weed plants compared with citrus trees was observed with the later plants usually being visited only after weed removal. The implications of the above observation on weed management as a means of controlling potential Xylella fastidiosa vectors belonging to the auchenorrhynchan species was discussed.