Studies on the response ofAmblyseius bibens [Acarina: Phytoseiidae] to conditions of prey scarcity

Various aspects of the ability of the predacious miteAmblyseius bibens Blommers to survive under conditions of prey scarcity were studied in the laboratory. The presence of water considerably lengthened survival in the absence of food. An ability to pierce leaves was not observed in the predator. Walking speed was little affected by hunger, but declined with inanition. Activity (=percentage time spent walking) was greatest in well fed females, and decreased with increasing hunger, and eventually with inanition. Hence, the area searched per unit time decreased with increasing hunger and inanition. Hungry predators showed greater activity on more hairy leaves. Hungry predators became more restive in the presence of a cover. A webbed area was preferred (as resting place) by the predator, whether hungry or not. Gut content, and hence initial feeding, was only representative for the state of hunger, if the availibility of water was accounted for. Duration of the complete recovery (oviposition) in the presence of ample food provided a measure of the original inanition. Many kinds of pollen might serve as alternate food.