Spatial Distribution Patterns of Parthenolecanium corni (Hemiptera, Coccidae) and of the Ampelovirus GLRaV-1 and the Vitivirus GVA in a Commercial Vineyard.

Gérard Hommay,Etienne Herrbach,Louis Wiss,Joël Chadoeuf,Catherine Reinbold

doi:10.3390/v12121447

Gérard Hommay, Etienne Herrbach + Show 3 more

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https://doi.org/10.3390/v12121447

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Abstract

Distribution patterns of the European fruit lecanium Parthenolecanium corni (Bouché) and of grapevine leafroll-associated virus-1 (GLRaV-1) and grapevine virus A (GVA) were monitored from 2003 to 2015 in a Riesling vine plot in the northeast of France. Virus spread was compared between two periods: 2003–2008 and 2009–2014. The percentage of infected vines increased from 54 to 78% for GLRaV-1 and from 14 to 26% for GVA. The spatial distribution of viruses and of P. corni was analysed using permutation tests and revealed an aggregative pattern. Virus distribution was not associated with the density of P. corni population on grapevines. However, GLRaV-1 and GVA spread mainly from initially infected vines. New GLRaV-1 and GVA infections were more frequent on vines near primarily infected vines, first anisotropically along the row, then between neighbouring rows. Virus spread was similar to those described in literature with grapevine mealybug species. This slow vine-to-vine progression suggests that P. corni was responsible for the virus spread, in accordance with the low mobility and low transmission capacities of its local population.

Highlights

Progressive reduction of insecticide use in vineyards, changes in farming practices, and increasing commercial exchanges have favoured the outbreak of scale insect (Hemiptera, Coccoidea) populations.Mealybugs (Pseudococcidae) and soft scales (Coccidae) dwelling on grapevine were for a long time considered as secondary pests, until they were shown to transmit grapevine leafroll-associated viruses (GLRaVs) in different winegrowing regions of the world [1,2]
At least five serologically distinct members of the Closteroviridae family, designated as grapevine leafroll-associated virus-1 (GLRaV-1), -2, -3, -4, and -7, are associated with leafroll disease [3,4,5]. Three of these viruses (GLRaV-1, -3, and -4), which belong to the Ampelovirus genus, are transmitted by several species of mealybugs and soft scales [1]
These vectors are able to inoculate three grapevine-infecting viruses associated with “rugose wood complex”: grapevine virus A (GVA), GVB, and GVE [1] assigned to the genus Vitivirus

Summary

Introduction

Progressive reduction of insecticide use in vineyards, changes in farming practices, and increasing commercial exchanges have favoured the outbreak of scale insect (Hemiptera, Coccoidea) populations.Mealybugs (Pseudococcidae) and soft scales (Coccidae) dwelling on grapevine were for a long time considered as secondary pests, until they were shown to transmit grapevine leafroll-associated viruses (GLRaVs) in different winegrowing regions of the world [1,2]. At least five serologically distinct members of the Closteroviridae family, designated as GLRaV-1, -2, -3, -4, and -7, are associated with leafroll disease [3,4,5]. Three of these viruses (GLRaV-1, -3, and -4), which belong to the Ampelovirus genus, are transmitted by several species of mealybugs and soft scales [1]. These vectors are able to inoculate three grapevine-infecting viruses associated with “rugose wood complex”: grapevine virus A (GVA), GVB, and GVE [1] assigned to the genus Vitivirus (family Betaflexiviridae).

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