Effects of Variety and Grape Berry Condition of Vitis vinifera on Preference Behavior and Performance of Drosophila suzukii

Abstract

Drosophila suzukii is an invasive fruit pest and represents a potential economic threat to viticulture. After first observations of D. suzukii in Europe in 2008, research mainly focused on the evaluation of the host range and infestation risk for fruit and berry crops. However, the risk assessment of D. suzukii in viticulture has only recently started. Understanding the factors influencing preferences of D. suzukii for host species and varieties as well as offspring performance is essential to improve management strategies. We investigated the field infestation of different grape varieties across Baden-Wuerttemberg, southwestern Germany, between 2015 and 2018. Moreover, we performed dual-choice assays in the laboratory to investigate whether adults show preferences for certain varieties and whether offspring performance differs between varieties. Furthermore, we studied the impact of grape damage on choice behavior. Field monitoring revealed that D. suzukii show preferences for red varieties, whereas almost no oviposition occurred in white varieties. The results of dual-choice assays confirmed that D. suzukii preference and performance are influenced by grape variety and that flies preferred damaged over intact "Pinot Noir", "Pinot Blanc", and "Müller-Thurgau" berries. Overall, these findings may have important implications for winegrowers regarding cultivated varieties, grape health, and insecticide reduction.

Texture features explain the susceptibility of grapevine cultivars to Drosophila suzukii (Diptera: Drosophilidae) infestation in ripening and drying grapes

“…The cultivar selection operated by D. suzukii in the field can be also linked to other factors such as skin colour, with a clear preference for the red cultivars, and berries health condition 18,22,27,44,46 . In addition, biochemical molecules as those of odours released by the grape colonizing microorganisms may stimulate D. suzukii egg deposition [20][21][22]44,[54][55][56][57][58] . Further studies should address whether the mechanical texture features of berries could influence the berries healthiness (e.g.…”

Physical and Chemical Traits of Grape Varieties Influence Drosophila suzukii Preferences and Performance

“…A breeding stock of the Asian fruit fly Drosophila suzukii was established from field-collected adults and maintained for over 50 generations at State Institute of Viticulture and Enology, Germany (as in Weißinger et al, 2019a ). The flies were kept in rearing cages (30 cm × 30 cm × 30 cm, Bugdorm-1, Megaview, Taiwan) in a climatic chamber (Viessmann, Allendorf, Germany) under controlled conditions (24°C, 60–70% r.h., L16:D8) and provided with a sugar-water source (5% sucrose) and a food source consisting of a mix of brewer’s yeast (Masterdog, Schwieberdingen, Germany) and dry sugar (1:1).…”

“…Grapes were harvested at typical variety-specific harvest °Brix (17.9–25.4, Table 1 ), which corresponds to the BBCH-stage 89 according to Lorenz et al (1994) . Detailed information on selection of investigated varieties, vineyards, berries and storage are described in Weißinger et al (2019a) . Randomly selected berries of the same grape clusters were used to assess behavioral responses of the insects as well as chemical and physical fruit and wax characteristics.…”

“…This frugivorous pest was accidentally introduced to Europe and North America and has become a well-established economic pest in several countries in the recent years ( Cini et al, 2012 ; Asplen et al, 2015 ; Poyet et al, 2015 ). The fly’s ability to infest intact, ripening, soft-skinned fruits including grapes, combined with its high fecundity and short development cycle, makes it a severe economic threat, especially for the small-fruit industry ( Lee et al, 2011 ; Weißinger et al, 2019a ; Little et al, 2020a ). Additionally, lesions in the cuticle caused by oviposition serve as preferred entry sites for microorganisms, leading to secondary infections, e.g., with acetic acid bacteria ( Ioriatti et al, 2018 ; Ebbenga et al, 2021 ).…”

“…Since D. suzukii females are able to actively pierce the intact skin of ripening fruits for oviposition ( Atallah et al, 2014 ), berry firmness is discussed to play a relevant role in their host selection ( Burrack et al, 2013 ; Rodriguez-Saona et al, 2019 ). In field and laboratory studies, we previously demonstrated that susceptibility differs within and between certain varieties of V. vinifera , with a general preference of D. suzukii for red over white varieties and damaged over intact berries ( Weißinger et al, 2019a , b ). Further investigations are necessary to understand potential cues driving this fruit-frugivore interaction.…”