CASCADING EFFECTS OF OLIVE FARM INTENSIFICATION ON PHYTOPHAGOUS INSECTS AND THEIR NATURAL ENEMIES

CASCADING EFFECTS OF OLIVE FARM INTENSIFICATION ON PHYTOPHAGOUS INSECTS AND THEIR NATURAL ENEMIES

Sasha Vasconcelos (CIBIO-InBIO, Portugal) | November 22, 2018 | 1st Iberian Meeting on Agroecological Research, Évora, Portugal

Olive farms are progressively expanding in the Mediterranean region, and have undergone a process of management intensification over the last two decades. Organic farm management that relies mostly on natural pest control, and traditional low-intensity farming involving low agrochemical input, are rapidly giving way to high-intensity regimes with very high agrochemical application. However, in spite of this widespread intensification process, little is known of its consequences for biodiversity and associated ecosystem services, such as natural pest control. To address this issue, we examined the abundance of phytophagous insects and their natural enemies (predatory arthropods and parasitoid wasps) across farms under different levels of management intensity, ranging from largely unmanaged to superintensive farms. Sampling was carried out in southern Portugal. Sixty sampling points within 38 olive farms were visited in Spring, Summer and Autumn, and canopy arthropods were vacuum-sampled. Preliminary results revealed significant declines in the abundance of some focal taxa in the most intensive regimes, suggesting that the growing application of chemical pesticides and fertilizers may be influencing the dynamics of plant-feeders and their controllers in Mediterranean olive farms.

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