Organic Farming and Cover-Crop Management Reduce Pest Predation in Austrian Vineyards

Abstract

Habitat simplification and intensive use of pesticides are main drivers of global arthropod declines and are, thus, decreasing natural pest control. Organic farming, complex landscapes, and local vineyard management practices such as implementation of flower-rich cover-crop mixtures may be a promising approach to enhance predator abundance and, therefore, natural pest control. We examined the effect of organic versus integrated management, cover-crop diversity in the vineyard inter-rows, and landscape composition on the natural pest control of Lobesia botrana eggs and pupae. Predation of L. botrana pupae was reduced by organic farming and species-poor cover-crops by about 10%. Predation rates of L. botrana eggs did not differ significantly in any of the studied management options. Dominant predators were earwigs (Forficulidae), bush crickets (Tettigoniidae), and ants (Formicidae). Negative effects of organic viticulture are most likely related to the negative nontarget effects on arthropods related to the frequent sulfur and copper applications in combination with the avoidance of strongly damaging insecticides by integrated winegrowers. While a 10% difference in predation rates on a single pest stage is unlikely to have strong practical implications, our results show that the assumed effectiveness of environmentally friendly agriculture needs to be evaluated for specific crops and regions.

Enhancement of the Diversity of Pollinators and Beneficial Insects in Intensively Managed Vineyards

“…Our results showed that within the most abundant genera were Coccinella and Chrysoperla, who are predators of aphids, and Sphaerophoria, who perform both pollination and predation functions. These observations coincide with those obtained by other authors [57,59,60,70,71] and prove that cover plants are a great tool for IPM.…”

Disentangling the Benefits of Organic Farming for Beetle Communities (Insecta: Coleoptera) in Traditional Fruit Orchards

“…Predatory and phytophagous beetles were not affected by the farming system. While this result is somewhat surprising, similar trends have been reported in other studies [30,33]; only the month drove the abundances of these trophic gilds. Summer drought is the defining feature of the Mediterranean climate.…”

“…Organic farming generally supports greater farmland biodiversity and benefits a range of taxa; however, the extent of those benefits is not completely understood, and generalization is not easy across taxa and functional groups [25,[29][30][31]. Although the benefits of organic farming seem to be less prominent in perennial than in annual crops, organic management of fruit orchards may increase insect diversity, improving the balance between sustainability and productivity in the agroecosystem [26,32,33]. Information on insect responses to farming system is available for perennial crops, such as vineyards, apple orchards, and olive orchards [32,34,35], but limited for cherry orchards, even though they comprise 426,000 ha of land worldwide and produce more than 2 million metric tons of cherries annually [36].…”

Positive effects of organic viticulture on carabid beetles depend on landscape and local habitat conditions

“…Recently, Ostandie et al (2021) showed highly variable responses across organisms of multiple trophic levels to organic viticulture. Moreover, several studies indicate that biodiversity may not benefit to the same degree from organic farming in perennial vineyard systems as in annual systems (e.g., bees and pollinators: Brittain, Bommarco, Vighi, Settele, & Potts, 2010; Kehinde & Samways, 2012; grasshoppers: Bruggisser et al, 2010; plants: Bruggisser et al, 2010; predatory mites: Reiff, Kolb, et al, 2021; spiders: Bruggisser et al, 2010; Kolb, Uzman, Leyer, Reineke, & Entling, 2020). Only recently, first information about the effect of organic viticulture on carabid beetles became available (Caprio, Nervo, Isaia, Allegro, & Rolando, 2015; Muneret et al, 2019; Ostandie et al, 2021; Uzman et al, 2020).…”