Landscape simplification increases vineyard pest outbreaks and insecticide use

Abstract

Diversifying agricultural landscapes may mitigate biodiversity declines and improve pest management. Yet landscapes are rarely managed to suppress pests, in part because researchers seldom measure key variables related to pest outbreaks and insecticides that drive management decisions. We used a 13-year government database to analyse landscape effects on European grapevine moth (Lobesia botrana) outbreaks and insecticides across c. 400 Spanish vineyards. At harvest, we found pest outbreaks increased four-fold in simplified, vineyard-dominated landscapes compared to complex landscapes in which vineyards are surrounded by semi-natural habitats. Similarly, insecticide applications doubled in vineyard-dominated landscapes but declined in vineyards surrounded by shrubland. Importantly, pest population stochasticity would have masked these large effects if numbers of study sites and years were reduced to typical levels in landscape pest-control studies. Our results suggest increasing landscape complexity may mitigate pest populations and insecticide applications. Habitat conservation represents an economically and environmentally sound approach for achieving sustainable grape production.

Unexpected Effects of Local Management and Landscape Composition on Predatory Mites and Their Food Resources in Vineyards

“…Furthermore, phytoseiid mite densities decreased when SNHs increased. These findings were in contrast with other studies, which showed positive relations between higher landscape diversity or higher shares of SNHs promoting biological control of different pests in vineyards [ 16 , 138 , 139 , 140 ]. Several studies demonstrated that SNHs (e.g., hedgerows, maple trees) were an important natural reservoir for phytoseiid mites [ 34 , 141 ], from where they could migrate into nearby vineyards [ 35 , 142 , 143 ] after their extinction by pesticides or when vineyards were newly established.…”

“…The effects of large monocultures and alternative habitats at landscape scale on pests and their natural enemies seem to differ with regard to the respective crop system and the pest species [ 15 ]. One reason for the diverging results could be related to pest stochasticity, which could mask the positive effects of landscape complexity on pest outbreaks [ 16 ].…”

“…It has been shown that landscape composition influences the effectiveness of natural enemies of some pest species. Diverse landscapes have reduced infestation of grape berry moth and insecticide applications in Spanish vineyards [ 16 ]. Similarly, mealybug and mite infestation decreased when the proportion of semi-natural habitats (SNHs) increased in the landscape [ 33 ].…”

Organic management and landscape heterogeneity combine to sustain multifunctional bird communities in European vineyards

“…In Europe, vineyards are managed with various intensification levels, but generally result in heterogeneous mosaics of seminatural habitats interspersed with large areas of grape dedicated to wine production. However, the combined effects of land use and climate changes, together with the use of agrochemicals and changes in soil management, induced a loss of landscape heterogeneity in European vineyards (Paiola et al, 2020;Paredes et al, 2021).…”

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

“…However, benefits of organic farming on pest control seem to be less prominent in perennial crops such as grapevine than in annual crops [ 9 , 10 ] and may depend on the landscape context [ 6 , 11 ]. Complex landscapes with higher proportions of seminatural areas often support higher levels of natural pest control [ 6 , 12 , 13 ]. Adjacent seminatural habitats, particularly woody vegetation, can promote natural enemies such as lacewings, spiders, predatory mites, rove beetles, and hymenopteran parasitoids in vineyards [ 14 , 15 ].…”