Tracking mite trophic interactions by multiplex PCR

Area of Science:

• Agroecosystems
• Biological Pest Control
• Molecular Ecology

Background:

• Phytoseiid mites are crucial natural enemies of pest mites in agriculture.
• Intraguild predation and alternative food sources can affect the efficacy of biological control.
• Molecular gut content analysis is vital for understanding mite feeding ecology.

Purpose of the Study:

• To develop and validate a multiplex PCR assay for identifying prey in phytoseiid mites.
• To assess DNA detectability over time for various prey types in a key predator, Euseius stipulatus.
• To investigate trophic interactions within Spanish citrus agroecosystems.

Main Methods:

• Designed new DNA primers for Phytoseiidae, Tetranychidae, and Thysanoptera.
• Multiplexed primers in a polymerase chain reaction (PCR) with universal plant primers.
• Estimated DNA detectability success over time (DS50) for different prey in Euseius stipulatus.

Main Results:

• The multiplex PCR successfully identified phytoseiids and alternative prey in the gut of Euseius stipulatus.
• DNA detectability success over time (DS50) varied significantly among prey types.
• DS50 values ranged from 1.3 hours (Frankliniella occidentalis) to 18.7 hours (Phytoseiulus persimilis).

Conclusions:

• This multiplex PCR method effectively tracks trophic relationships in citrus agroecosystems.
• Understanding alternative food sources is essential for enhancing biological control of Tetranychus urticae.
• The approach is potentially applicable to similar agricultural environments.