Dispersal ofPhilaenus spumarius(Hemiptera: Aphrophoridae), a Vector ofXylella fastidiosa, in Olive Grove and Meadow Agroecosystems

Abstract

The introduction of the Xylella fastidiosa Wells bacterium into Apulia (South Italy) has caused the massive dieback of olive trees, and is threatening olive production throughout the Mediterranean Region. The key vector of X. fastidiosa in Europe is the spittlebug Philaenus spumarius L. The dispersal capabilities of P. spumarius are poorly known, despite being a key parameter for the prediction of the spread of the bacterium. In this study, we have examined the dispersal of P. spumarius adults in two different agroecosystems in Italy: an olive grove in Apulia (Southern Italy) and a meadow in Piedmont (Northern Italy). Insects were marked with albumin and released during seven independent trials over 2 yr. The recapture data were pooled separately for each agroecosystem and used to estimate the dispersal kernels of P. spumarius in the olive grove and in the meadow. The diffusion coefficient estimate for P. spumarius was higher in the meadow than in the olive grove. The median distance from the release point for 1 d of dispersal was 26 m in the olive grove and 35 m in the meadow. On the basis of our model, we estimated that 50% of the spittlebug population remained within 200 m (98% within 400 m) during the 2 mo period of high abundance of the vector on olives in Apulia. The dispersal of P. spumarius is thus limited to some hundreds of meters throughout the whole year, although it can be influenced to a great extent by the structure of the agroecosystem.

Dispersal of Neophilaenus campestris, a vector of Xylella fastidiosa, from olive groves to over‐summering hosts

“…Our results suggest that N. campestris is able to travel more than 2000 m in 35 days. These results contrast with those obtained by Bodino et al., (2020) who estimated that 98% of the P. spumarius population moved within a radius of 400 m. However, they did not specify the distance moved by the remaining 2% of the population. One of the limitations of the MMR techniques is that a very high sampling effort is needed to recover marked insects at long distances from the release point.…”

“…Bodino et al. (2020) performed a MMR study in southern Italy, sampling in concentric circles from 10 to 120 m from the released point. They estimated 98% of P. spumarius population disperse in a radius of 400 m. In contrast, Conyers et al (2020) found that the maximum distance moved by P. spumarius was 10 m in two days.…”

Tracking the outbreak: an optimized sequential adaptive strategy for Xylella fastidiosa delimiting surveys

“…The species is naturally transmitted by xylem sap-feeding insects. The natural spread of X. fastidiosa depends on these insects, which can propagate the disease from plant to plant depending on their dispersal capability and transmission efficiency (Bodino et al 2020). Human-assisted spread is mainly driven by the movement of infected plant materials (EFSA 2018).…”

Optimal leap angle of legged and legless insects in a landscape of uniformly distributed random obstacles

“…Moreover, froghoppers represent the key vectors for the Xylella fastidiosa Wells bacterium, which led to a dramatic epidemic disease on olive trees in the Mediterranean area [12]. The dispersal capabilities of froghoppers are still not very well known and a recent field study has shown that they could be more effective than expected [13]. A deeper understanding of the key factors that lead to the effectiveness of dispersion of froghoppers could help the identification of strategies to mitigate the fast spread of the dieback of olive trees.…”