Response of the predatory mite Cydnoseius negevi (Acari: Phytoseiidae) to webbing of the date palm mite, Oligonychus afrasiaticus (Acari: Tetranychidae), on date palm fruits and leaves.

Abstract

The behavioral response of a generalist phytoseiid predator, Cydnoseius negevi (Swirskii & Amitai) (Acari: Phytoseiidae) to the complicated webbing of the date palm mite (DPM) Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) was evaluated for the first time on date palm leaves and fruits, both in the laboratory and on field-collected samples. Cydnoseius negevi used its first pair of legs in a swimming-like to-and-fro movement to penetrate the complicated webbing of DPM and demonstrated three attack behaviors, i.e., patrolling (PG), web invasion (WI), and web penetration (WP), against the webbing of DPM on date fruits and leaves. The time spent by the predatoron attack behaviors was significantly longer in the laboratory for treatments where either more preyfemales or immature stages along with females were present. The time spent by C. negevi on response behaviors such as searching, grooming, and resting increased with increased number of DPM females and with the addition of immature stages along with DPM females. Cydnoseius negevi, even though being a generalist phytoseiid predator, showed its potential towards penetrating the complex dense webs of DPM on date palm fruits and leaves. If released in suitable numbers prior to establishment of DPM colonies, C. negevi may prove to be an effective biological control agent.