Mechanical management of weeds drops nymphal density of Xylella fastidiosa vectors

Xylella fastidiosa Wells (1987) (Proteobacteria:Xanthomonadaceae) is a xylem pathogen bacterium transmitted by xylem feeder insects that causes several important plant diseases such as Pierces disease in grapes or leaf scorch in almond and olives trees. The bacterium was detected in the Balearic Islands in October 2016, including three subspecies: fastidiosa, multiplex and pauca. The major potential vectors described in the Balearics are Philaenus spumarius L. and Neophilaenus campestris Fallen (1805). In order to interfere the life cycle of vectors, we tested the effect of mechanical control of the plant cover on the most vulnerable phases, such as nymphs and/or newly emerged adults. For this, we selected four organic orchards in Mallorca, three olive and one vineyard plots. Owners of each selected plot conducted mechanical control according to their common procedures and their own machinery, which in general included cut and tillage of the plant cover during March-April. Nymph abundance per surface (30 sampling points/treatment/orchard x 0,25 m2) was measured in each plot in a weekly basis before and after mechanical control. Our results indicated that either tillage and mowing decreased nymphal density of X. fastidiosa vectors in both types of crops. These results contribute to the integrated pest management of vectors by conducting feasible farm-based management of the regular plant cover. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/512680v1_ufig1.gif" ALT="Figure 1"> View larger version (81K): org.highwire.dtl.DTLVardef@8b9383org.highwire.dtl.DTLVardef@181b000org.highwire.dtl.DTLVardef@149ed7eorg.highwire.dtl.DTLVardef@87254d_HPS_FORMAT_FIGEXP M_FIG C_FIG