Linear functional response by two pupal Drosophila parasitoids foraging within single or multiple patch environments.

Area of Science:

• Ecology
• Entomology
• Behavioral Ecology

Background:

• Functional response models predator/parasitoid feeding rates based on prey/host density.
• Linear functional responses are uncommon in insect parasitoids, making this study significant.

Purpose of the Study:

• To investigate the functional response of two insect parasitoid species to varying host densities.
• To determine if experimental design influences the observed functional response.

Main Methods:

• Three experimental designs were employed: fixed time within patch, variable time functional response, and selective functional response.
• Parasitoids were exposed to different densities of Drosophila hosts (D. suzukii and D. melanogaster).
• Parasitism events and host handling times were recorded.

Main Results:

• Both Pachycrepoideus vindemiae and Trichopria drosophilae displayed a linear functional response.
• The number of hosts parasitized increased linearly with density until an upper limit was reached.
• P. vindemiae's response was limited by egg supply and handling time; T. drosophilae was limited by handling time.

Conclusions:

• The study demonstrates an unusual linear functional response in two insect parasitoid species.
• A constant attack rate and incremental foraging strategy likely explain the observed linear response.
• Findings provide insights into parasitoid foraging behavior and population dynamics.