Limited predator-induced dispersal in whiteflies

Area of Science:

• Ecology
• Behavioral Ecology
• Insect Ecology

Background:

• Prey species often avoid habitats occupied by predators.
• The propensity of prey to emigrate from current habitats upon predator exposure is less understood.
• Adult whiteflies can disperse to new plants, while their predators, predatory mites, are slow dispersers.

Purpose of the Study:

• To investigate if adult whiteflies emigrate from plants infested with predatory mites.
• To determine if plant-to-plant dispersal of whiteflies is triggered by the presence of predatory mites.
• To assess the influence of interplant distance on whitefly dispersal behavior.

Main Methods:

• A greenhouse experiment was conducted using whiteflies and predatory mites on rows of cucumber plants.
• Whiteflies were released on the first plant, with predators introduced on the same or adjacent plants, or absent (control).
• Interplant distances were set at 0.6 m or 2 m to evaluate dispersal rates and success.

Main Results:

• Adult whiteflies dispersed more rapidly between closely spaced plants (0.6 m) when predators were present.
• Dispersal speed was not significantly affected by predator presence at greater distances (2 m).
• The overall proportion of dispersing whiteflies was low, indicating a reluctance to leave, which increased with plant distance.

Conclusions:

• Adult whiteflies exhibit a reluctance to disperse, even when facing predation risk.
• Dispersal decisions are influenced by the distance to potential new habitats, likely due to uncertainty in finding suitable plants.
• Whiteflies may not always disperse to escape predators if the perceived risk of finding a new, safe habitat is too high.