Scientific Opinion: Improving the Definition of Grape Phylloxera Biotypes and Standardizing Biotype Screening Protocols

Abstract

Grape phylloxera biotypes are defined by their specific performance on, or preference for, a particular host (e.g., feeding on a particular rootstock). Numerous studies have phenotyped phylloxera biotypes, particularly with regard to their performance on various hosts, but the results are difficult to compare because there is neither a homogenous nomenclature nor a standardized protocol for phenotyping. To improve communication within the scientific community, we offer a simplified phylloxera biotype classification to allow clear data interpretation and effective communication. We also introduce the standard techniques employed for phylloxera phenotyping and discuss their advantages and disadvantages.

Grape phylloxera (Daktulosphaira vitifoliaeFitch) in Argentina: ecological associations to diversity, population structure and reproductive mode

“…From now on, we will refer to them as California A and B biotype samples. In this study, the term biotype is used as proposed by Forneck et al (). In addition, three Peruvian foliar samples from an earlier study (Lund et al ) were utilised as an outgroup.…”

First European leaf-feeding grape phylloxera (Daktulosphaira vitifoliae Fitch) survey in Swiss and German commercial vineyards

“…As an introduced pest, grape phylloxera can be commonly found nowadays in commercial vineyards, both feeding on roots of partially resistant rootstocks and leaves of partially resistant grapevine cultivars (Powell et al 2013;Griesser et al 2015). Recent reports show the incidence of leaf-feeding phylloxera on leaves of both partially resistant and formerly resistant vines (Bao et al 2014;Fahrentrapp et al 2015;Forneck et al 2016). The vitality and lifespan of vineyards infested by root-feeding phylloxera (later on termed Bphylloxerated^) depend on many factors, including rootstock origin, phylloxera biotype and population density, soil type, vineyard management practices and diverse abiotic and biotic stress factors (see Powell et al 2013).…”

Hot water immersion as a disinfestation treatment for grapevine root cuttings against genetically diverse grape phylloxera Daktulosphaira vitifoliae Fitch

“…The effectiveness of HWTs on achieving mortality of phylloxera infesting root material was, therefore, examined across six endemic strains (G1, G4, G7, G19, G20 and G30). The six genetic strains were selected based on a representation of a range of biotypes that exist in Australia (Forneck et al , Corrie et al , Hoffmann , Forneck et al ).…”