Persimmon orchards harbor an abundant and well-established predatory mite fauna

Abstract

Traditionally persimmon cultivation has been considered a minor crop in Spain, but in recent years this crop has experienced an important increase in both cultivated area and production. This increase has been mainly attributed to the widespread adoption of a new postharvest treatment which considerably extends the fruit commercialization period. The sudden expansion of this crop has not allowed time to correctly develop an integrated pest management (IPM) program. Consequently, chemical treatments have become the main strategy to lessen the impact of pests. Given the importance of phytoseiids in other Mediterranean fruit crops, where they are the basis of IPM, we sought to determine whether they could be similarly employed in persimmon crops. For this, we studied the predatory mite complex, the phytoseiid population dynamics and the potential prey for them during three consecutive seasons in four persimmon orchards, two of which managed conventionally, and two organically. Phytoseiids were abundant throughout the season, found on average at a density of more than 1 predatory mite per leaf. The most abundant species was Euseius stipulatus (57.3%) followed by Typhlodromus phialatus (24.8%), Amblyseius andersoni (17.1%) and Paraseiulus talbii (0.8%). Persimmon leaves provided a diversity of prey for predatory mites throughout the year, the most abundant being mealybugs, coccids, whiteflies and thrips. The abundance of predatory mites was significantly correlated to the abundance of potential prey available. From our results we anticipate that phytoseiids will be key actors in the development of persimmon IPM. Their role in this crop is discussed, as well as how to conserve their populations.

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