South Africa Wine Technical Yearbook 2025

Boosting biodiversity with plants and insects Cover crops and natural vegetation are essential tools for promoting functional biodiversity, particularly among beneficial insects. Key plant traits – like root diameter, nitrogen-fixing capacity and flowering duration – directly influence ecosystem services such as soil aggregation, nutrient cycling, and food sources for pollinators. Field research in north-eastern Italy revealed that inter row management can significantly shape insect populations. For example, spontaneous grasses left to grow without mowing increased the abundance of predatory mites, which help control grapevine pests. However, these same conditions also favoured pests like the American grapevine leafhopper – a reminder that managing biodiversity is a balancing act. The selection of cover crop species should therefore be strategic, ensuring that they support beneficial species, while minimising conditions that favour pests. Timing and frequency of mowing can further fine-tune these dynamics, helping to suppress unwanted species, while maintaining habitat for allies.

Avian and mammalian allies – bats and birds Nature’s pest control doesn’t end with insects. Bats and birds also play critical roles in functional biodiversity. In Chile, bats were found to reduce pest damage and hence boost grape yields by 7% through their control of moth larvae. Similarly, birds of prey such as the American kestrel and New Zealand falcon are used in vineyards to deter pest birds that damage grapes. Encouraging these predators involves both habitat creation and structural support. Nesting boxes have proven effective in attracting owls, kestrels and other raptors. In California’s Napa Valley, one study estimated that a single pair of barn owls removed over 1 000 rodents in one nesting cycle – offering both an economic and ecological win by reducing the need for rodenticides. Even smaller insectivorous birds benefit from vineyard practices like cover cropping, which increases the abundance of insects they feed on. Landscape features such as nearby hedgerows, woodlands, and even remnant oak trees can further enhance bird and bat activity, reinforcing the idea that vineyard biodiversity extends beyond the vines.

TABLE 1. The roles of fauna in regenerative viticulture systems and the impact of management practices on their abundance. [ (Extracted from O’Brien, F., Nesbitt, A., Sykes, R. & Kemp, B. (2025). Regenerative viticulture and climate change resilience. OENO One 59(1), as allowed by the following Creative Commons licence: https://creativecommons.org/licenses/by/4.0/.] Animal Viticultural practices to manage and encourage animal presence Impacts References

Weed control between and under the vines, wild animal deterrent, sucker shoot removal, leaf removal, stimulation of soil ecosystem carbon flux, increased subsoil carbon storage. Weed control, fertiliser provision, contribution to soil biomass, copper removal from soil. Reduction in damage to grapes by birds, including Turdus migratorius (American robin), T. merula (blackbird), T. philomelos (song thrush), Sturnus vulgaris (starling) and Zosterops lateralis (silvereye), reduction in economic loss inflicted by rodents on vine roots, stalks, irrigation lines and farm machinery due to burrowing.

Integration of sheep in well-established vineyards during the winter dormancy period with consideration for animal care and health. Training system adaptations and/or use of specific breeds can enable growing season grazing. High-density short-duration rotational grazing.

Schoof et al. (2021); Conrad et al. (2022); Brewer et al. (2023)

Sheep

Massaccesi et al. (2019)

Geese

Rearing geese in the vineyard during growing season.

Introduction or encouragement of raptors as biocontrol agents. Installation or nest boxes to attract species such as Falco sparverius (American kestrel) and Tyto furcate (American barn owl).

Whisson and Guisti (1998); Kross et al. (2012); Jasinski et al. (2021); St George and Johnson (2021); Monteagudo et al. (2023)

Birds of prey

Introduction of F. novaseelandiae (New Zealand falcon).

Installation of nest boxes to increase insectivorous birds, including cavity-nesting birds; increased uncropped areas; cover cropping; establishment of hedges, trees, woodland patches, traditional orchards, grassland areas tailored to local context/ species increases breeding. The preservation or provision of native vegetation bordering the vineyard, along rivers and hedgerows to provide foraging habitat for bats through presence of prey insects; preservation of remnant oak trees to increase number or species and activity compared to open treeless areas.

Rollan et al. (2019); Herrera et al. (2022); Olmos-Moya et al. (2022); Rosch et al. (2023) Baroja et al. (2019); Froidevaux et al. (2017); Polyakov et al. (2019); Charbonnier et al. (2021); Rodriguez-San Pedro et al. (2020); Chaperon et al. (2022)

Biocontrol of insect pest species.

Insectivorous birds

Biocontrol of insect pest species Lobesia botrana (grapevine moth) and Sparanothis pilleriana (leaf rolling tortrix) by multiple species, including Rhinolophus hipposideros (lesser horseshoe bat), reduction in insect damage.

Bats

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TECHNICAL YEARBOOK 2025