Diverging Effects of Landscape Factors and Inter-Row Management on the Abundance of Beneficial and Herbivorous Arthropods in Andalusian Vineyards (Spain).

Entrenas Entrenas,Judt Judt,Guzmán Guzmán,Winter Winter,Gómez Gómez,Paredes Paredes,Cabezas Cabezas,Zaller Zaller

doi:10.3390/insects10100320

Abstract

Land use at landscape and field scales can increase the diversity and abundance of natural enemies for pest control. In this study, we investigated interactions between landscape elements (semi-natural vegetation, olive orchards, vineyards, other agricultural areas) and inter-row management (vegetation cover vs. bare soil) in relation to arthropod populations in Andalusian vineyards. Arthropods were collected from grapevine foliage in 15 vineyards using suction sampling. Landscape structure was analyzed within a 750 m radius surrounding the studied vineyards. Arthropods were categorized into functional groups (predators, parasitoids, herbivores), and their responses to the most influencing factors were analyzed by likelihood methods and model selection. Of the total of 650 arthropods collected, 48% were predators, 33% herbivores and 19% parasitoids. Numbers of predatory aeolothrips, parasitoids and herbivorous cicadas in the study vineyards decreased with an increased proportion of vineyards in the surroundings. Spider populations in vineyards increased with increasing proportions of other agricultural fields (non-flowering crops) in the surroundings. Semi-natural elements and olive orchards had no influence on the abundance of collected arthropods. We observed synergistic effects between landscape elements and inter-row management. The total numbers of arthropods, herbivores and parasitoids in vineyards benefitted from inter-row vegetation, while spiders benefitted from bare soil. Our findings underline the importance of both surrounding landscape elements and vineyard ground cover management to promote beneficial arthropods for potential natural pest control.

Highlights

The intensification of agriculture, with increasing field sizes at the expense of natural and semi-natural elements and high pesticide and fertilizer inputs, causes serious environmental problemsInsects 2019, 10, 320; doi:10.3390/insects10100320 www.mdpi.com/journal/insectsInsects 2019, 10, 320 including habitat and biodiversity loss [1,2,3]
Biodiversity is strongly connected with ecosystem services such as natural pest regulation [4,5,6], and the conservation and protection of biological diversity has become an important part of agri-environmental policies and science [7]
Ground cover with perennial crops commonly stimulates the abundance of beneficial arthropods [36,37,38,39,40] but this effect depends on various factors such as the type, composition and management of the cover crop; type and management of the field crop; type of natural enemies and pest arthropods; and climatic conditions [33,41,42,43]

Summary

Introduction

The intensification of agriculture, with increasing field sizes at the expense of natural and semi-natural elements and high pesticide and fertilizer inputs, causes serious environmental problemsInsects 2019, 10, 320; doi:10.3390/insects10100320 www.mdpi.com/journal/insectsInsects 2019, 10, 320 including habitat and biodiversity loss [1,2,3]. Practices stimulating CBC include the establishment, modification and management of natural and semi-natural elements (SNEs), such as cropland boundaries, hedgerows, fallows, grasslands, woodlands and forests. These SNEs can provide food, alternative prey and hosts, shelter, overwintering sites and other essential resources [11,12,13]. Improved local habitat quality, e.g., via vegetation cover, can enhance natural enemy populations and can be advantageous for crop production, especially in simple structured landscapes [2,9,26,34,35]. Most previous studies did not consider possible synergistic effects between ground cover and surrounding landscape structure on natural enemy populations in perennial crop fields [44,45]

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