Intraguild Predation of the Acariphages Phytoseiulus persimilis Ath.-H. (Parasitiformes, Phytoseiidae) and Feltiella luboviae Fedotova et Kozlova (Diptera, Cecidomyiidae) in Shared Habitats

The relationships between the acariphages Phytoseiulus persimilis and Feltiella luboviae, narrow oligophages used to protect plants from spider mites in greenhouses, were studied under laboratory conditions. Their behavior was studied in terms of their possible intraguild predation (IGP) at different densities of their shared prey, the spider mite Tetranychus urticae. Our results suggest that Ph. persimilis can distinguish the eggs of its potential competitor F. luboviae from the morphologically different eggs of the spider mite, and the eggs of F. luboviae from the morphologically similar eggs of the specialized aphidophage Aphydoletes aphidimyza. Phytoseiulus persimilis can destroy the eggs of the acariphagous gall midge; in the experiment, the egg elimination rate increased as the prey density decreased. At the same time, Ph. persimilis ignored eggs of the aphidophagous gall midge. The larvae of F. luboviae showed no aggression towards eggs of the predatory mite but were able to prey on early immature stages of this mite, regardless of the density of the main prey. Phytoseiulus persimilis and F. luboviae can be both intraguild predators and intraguild prey for each other, but their level of IGP predation appears to be low.