Identification of Vitis Cultivars, Rootstocks, and Species Expressing Resistance to a Planococcus Mealybug

Abstract

Mealybugs cause economic loss to vineyards through physical damage, fouling fruit and leaves with honeydew, and the transmission of viruses. Planococcus ficus is one of several mealybug species in vineyards, and one that causes economic damage over a relatively large global range. To develop novel management tools, host resistance to P. ficus, which has not previously been identified for any grape cultivars, was studied. Ten grape lines (species, cultivars, and rootstocks) were evaluated for P. ficus resistance across two separate potted plant assays. Significant differences were detected among cultivars and rootstocks in the recorded number of P. ficus juveniles, adults, and egg sacs. Cabernet Sauvignon and Chardonnay were two of the most favorable grape cultivars for mealybug population growth, whereas rootstocks IAC 572, 10-17A, and RS-3 all demonstrated some level of resistance. Southern fire ant (Solenopsis xyloni) was positively associated with mealybug populations, but did not have a negative effect on the observed presence of other arthropod species including potential predators.

The Effect of Scale Insects on Growth Parameters of cv. Chardonnay and cv. Sauvignon Blanc Grapevines Grown in a Greenhouse

“…Principal component analysis using chemicals extracted from leaves collected from several cultivars in the field suggests that a difference exists between resistant and susceptible cultivars [ 19 ], but whether this represents a response to scale insects or is simply correlated with an apparent resistance difference requires further study. Riesling cultivars showed very little change in gene expression following relatively short exposures (6 and 96 h) to the mealybug Planococcus ficus (Signoret) [ 38 ], while other cultivars may have some tolerance or resistance to mealybugs [ 39 ]. Lawo, Weingart, Schuhmacher and Forneck [ 9 ] indicate that volatiles varied when phylloxera were present on a single resistant cultivar, but the time over which this change occurred was relatively short.…”

Transmission of Grapevine Ampelo- and Vitiviruses by the Bohemian Mealybug Heliococcus bohemicus Šulc (Hemiptera: Pseudococcidae)

“…In Europe, Pa. corni was shown to transmit GLRaV-1 but not GLRaV-3 [ 21 , 32 , 39 ], though GLRaV-3 transmission by this species was reported in Washington State, USA [ 40 ]. Variations of transmission rates within a given vector species are likely due to a combined effect of experimental conditions, vector and virus intraspecific variability, and differential susceptibility of grapevine varieties to either the virus or vector [ 41 ].…”

Sustainable management of the vine mealybug in organic vineyards

“…Damien et al 2017;Michaud 2018;Santoiemma et al 2020). The tolerance of rootstocks and cultivars to P. ficus infestations has been recently investigated in potted plants (Naegele et al 2020), indicating the cultivars Chardonnay and Cabernet Sauvignon as favorable substrates for VMB population growth, whereas the rootstocks IAC 572, 10-17A and RS-3 reduced the pest development. Naegele et al (2020) also suggested that physical and/ or chemical features may affect mealybug settling, feeding and host attractiveness, being therefore involved in the resistance mechanisms (antibiosis and antixenosis).…”

“…The tolerance of rootstocks and cultivars to P. ficus infestations has been recently investigated in potted plants (Naegele et al 2020), indicating the cultivars Chardonnay and Cabernet Sauvignon as favorable substrates for VMB population growth, whereas the rootstocks IAC 572, 10-17A and RS-3 reduced the pest development. Naegele et al (2020) also suggested that physical and/ or chemical features may affect mealybug settling, feeding and host attractiveness, being therefore involved in the resistance mechanisms (antibiosis and antixenosis). However, grapevine plants displayed a weak transcriptional response to P. ficus feeding, with a single gene, pathogenesis-related protein 1, being expressed as a response of mealybug attack (Timm and Reineke 2014).…”

“…Rational strategies to avoid the establishment of VMB populations should be implemented since vineyard planting. Even though cultivar and rootstocks showed different levels of susceptibility to VMB development (Naegele et al 2020), scion and rootstock choice is driven by economic interests rather than phytosanitary reasons. Nevertheless, planting of mealybug-free nursery stock is critical in order to avoid early infestations on young grape cuttings and postpone mealybug establishment in vineyards (Daane et al 2004c).…”