Management strategies against Drosophila suzukii: insights into Swiss grape growers choices

Abstract

Background In 2017, we investigated measures adopted by Swiss grape growers in response to Drosophila suzukii by conducting a survey presenting information obtained from 372 growers on 1708 vineyards. Results We found the strategies adopted to be heterogeneous and largely dependent on grape variety (table vs. wine grapes). We identified six clusters of control methods to combat D. suzukii, the most important of which involves using a combination of control methods such as insecticides, mass trapping and sanitation measures, especially pinching of foliage or mowing and mulching. Grape growers in our sample rely primarily on information from public institutions or other growers and the majority plan to continue taking sanitation measures to combat D. suzukii. Conclusion Our results suggest that strategies adopted in Switzerland differ widely, not only between growers, but also at a vineyard and regional level. Thus, policies and extension services should be targeted (e.g. to varieties and regions) and tailored to types of growers. We find that preventive measures are important when combatting D. suzukii and can reduce post‐infestation measures such as pesticide usage. In our sample, biological insecticides, such as kaolin, played a vital role in the control of D. suzukii and merit further support. © 2019 Society of Chemical Industry

Large-arena field cage releases of a candidate classical biological control agent for spotted wing drosophila suggest low risk to non-target species

“…The cage releases were conducted in two sites in Switzerland, which correspond geographically to southern and northern extremes of the country and exhibit different climatic conditions, under which D. suzukii has been reported to cause damage to fruits (Kenis et al 2016;Knapp et al 2019). South of the Alps, the site was situated in Cadenazzo (46.1600, 8.9342;200 m a.s.l.…”

Behavioral manipulation of Drosophila suzukii for pest control: high attraction to yeast enhances insecticide efficacy when applied on leaves

“…[14][15][16][17] Despite existing pre-harvest regulations, pesticide residues cause problems with respect to marketing and consumer safety. [18][19][20][21] Moreover, application of broad-spectrum insecticides, 14,22,23 together with recent findings on insecticide resistance in D. suzukii 16,24,25 have increased the need for alternative methods and improving insecticide efficacy.…”

The economic impact of Drosophila suzukii: perceived costs and revenue losses of Swiss cherry, plum and grape growers

“…However, it must be noted that growers adopt bundles of measures, i.e. typically use a number of different measures to deal with D. suzukii 8 …”

“…Infested fruit is unmarketable due to zero tolerance policies 7 . In response, growers adopt multiple measures to prevent and control infestation 3,8,9 . The economic impact of D. suzukii is expected to be substantial, but its magnitude is still largely unknown 10–12 …”

“…6 6 Note that in Switzerland, kaolin, a naturally occurring mineral clay, is widely used, especially in vineyards 8 . Kaolin has a repellent effect and dissuades oviposition, while posing no significant hazards to human health.…”