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

Abstract

Despite the fact that persimmon cultivation has been traditionally considered a minor crop in Spain, in recent years this crop has experienced an important increase in both cultivated area and production. This increase has been mainly attributed to the generalized adoption of a new postharvest treatment which allows the considerable extension of the fruit commercialization period. The sudden expansion of this crop has not allowed time to correctly develop an integrated pest management program (IPM). 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. 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 diverse abundance of prey for predatory mites throughout the year, being mealybugs, coccids, whiteflies and thrips the most common. 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 and how to conserve their populations in this crop are discussed in this research.