Landscape composition predicts the distribution of Philaenus spumarius, vector of Xylella fastidiosa, in olive groves

Giacomo Santoiemma,Francesco Sanna,Nicola Mori,Giovanni Tamburini,Lorenzo Marini

doi:10.1007/s10340-019-01095-8

Giacomo Santoiemma, Francesco Sanna + Show 3 more

Open Access

https://doi.org/10.1007/s10340-019-01095-8

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Abstract

The meadow spittlebug, Philaenus spumarius (Hemiptera: Aphrophoridae; Linnaeus, 1758), is considered the main vector in the ongoing Xylella fastidiosa outbreak in the olive groves of southern Italy. Identifying the factors driving the spatial distribution of P. spumarius is of primary importance to determine X. fastidiosa infection risk in healthy olive groves. Here, we investigated the local and landscape factors shaping the occurrence and abundance of P. spumarius by sampling 182 olive groves over 2 years in the Abruzzo region. We found the occurrence and abundance of the vector to be positively associated with the proportion of olive groves in the landscape and negatively with the cover of vineyards. Philaenus spumarius best responded to landscape processes at small spatial scale (125–250 m) confirming the available information regarding its dispersal ability. At the local scale, soil management and pesticide application did not affect the vector probably because both interventions were not timed according to the vector biology and ecology. Our findings suggest that the management of agricultural landscape mosaics can drive the spatial distribution of P. spumarius. In particular, the landscape composition of the close surrounding of the olive groves may potentially influence the emergence probability of local X. fastidiosa epidemics through its effects on the vector spatial distribution and activity.

Highlights

Xylella fastidiosa is a xylem-limited gram-negative bacterium, known to be the causal agent of a variety of economically important diseases in commercial crops and ornamental plants in North and South America (Purcell 2013; Sicard et al 2018)
The probability of occurrence and the abundance of P. spumarius was both positively influenced by olive grove cover in the landscape (Fig. 2a, d) and negatively affected by vineyard cover (Fig. 2b, d)
P. spumarius best responded to landscape processes at small spatial scale (125–250 m) confirming the available information in the literature regarding its dispersal ability (Weaver and King 1954)

Summary

Introduction

Xylella fastidiosa is a xylem-limited gram-negative bacterium, known to be the causal agent of a variety of economically important diseases in commercial crops and ornamental plants in North and South America (Purcell 2013; Sicard et al 2018). In Europe, X. fastidiosa was first recorded on olive trees in southern Italy (Puglia region, province of Lecce) where it has been recognized to be the main cause of the so-called olive quick decline syndrome (Saponari et al 2013, 2017; Loconsole et al 2014). The chances of eradicating X. fastidiosa from the region have been showed to be extremely low (Strona et al 2017) and new introductions of infected plants from outside Europe have already been recorded in southern France and in the island of Mallorca (Denancé et al 2017; EPPO 2016). There is, an urgent need to better understand the cryptic epidemiology of the outbreak, in order to define new management strategies to contain the epidemic (Strona et al 2017; Sicard et al 2018)

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