CONICET | Buscador de Institutos y Recursos Humanos

Universidad de Málaga/ Consejo Superior de Investigaciones Científicas/Instituto de Hortofloricultura Subtropical y Mediterránea/Instituto de Investigación y Formación Agraria y Pesquera

Resumen:

The predation between arthropods whose shared preys are located in different structures of plant depends on the probability of encounter between them. In strawberry plants, Frankliniella occidentalis in flowers and Tetranychus urticae in leaves are main prey of Orius insidiosus and Neoseiulus californicus, respectively. Each prey could be alternative food for the other predator and O. insidiosus is intraguild predator of N. californicus. With scarcity of the main prey, predators move from one structure to another one in the plant looking for alternative prey. Intraguild predation in this system will be affected by the location of predators in the strawberry plant. The objectives were: a) estimate the rate of consumption of thrips by N. californicus on leaves and flowers; b) evaluate the effect of the abundance of main and alternative prey on setting of N. californicus in the plant. The predator rate of consumption on thrips was estimated by laboratory tests. To determine the abundance of predator in leaves and flowers and those of their prey, 25 leaves and flowers were biweekly taken in five plots in La Plata, Argentina, during 2012-2014. The consumption rate was similar (P= 0.147) in leaves and flowers. The number of N. californicus on flowers was low when T. urticae was abundant in leaves, regardless of the number of thrips in flowers. The abundance of N. californicus on flowers increased when thrips increased and when its main prey decreased in leaves. In addition, the predator was present in flowers even in the absence of thrips, probably feeding pollen. When their main prey is scarce, N. californicus would find in flowers alternative food to survive. However, the probability of encounters with his intraguild predator could increase.