An invisible army of 125,500 mites and insects has been deployed in Tarragona to protect ornamental orange trees from pests such as whiteflies and mealybugs. This initiative by the City Council, through the Parks and Gardens department, aims to combat these pests without resorting to traditional insecticides, by using natural predators.
Gardeners have hung sachets containing 250 individuals of Amblyseius swirskii, a mite that preys on whitefly eggs, on the branches of trees located in various areas of the city, including Carrer de les Coques, Via Augusta, Rambla Nova, carrer August, Plaça de la Pagesia, and Plaça Sant Joan. Each adult mite can consume between 2 and 4 pest larvae.
This is the first time that the release of natural predators has been carried out simultaneously in several areas of the city, following successful trials in previous years. In addition to the mites, 500 specimens of Cryptolaemus montrouzieri, a ladybug that preys on cottony mealybugs, have been released. This pest weakens plants and secretes a sticky honeydew.
Pilar Bargalló, head of Parks and Gardens, explains that the initiative involves helping nature with its own tools. In some instances, nature collaborates spontaneously, as recently observed with a colony of Cryptolaemus montrouzieri that emerged naturally at the Balcó del Mediterrani.
Guillermo García de Castro, the Environment Councillor, emphasizes that the goal is pest control while respecting beneficial fauna and avoiding the use of insecticides. It is anticipated that citizens will not notice the presence of these insects, unless they observe them around streetlights at night, as they carry out their control work.
