Validation of the Berlese-funnel technique for thrips extraction

Area of Science:

• Agricultural Entomology
• Plant Pathology
• Analytical Chemistry

Background:

• The Berlese-funnel technique is crucial for isolating quarantine insects from plant material.
• Accreditation to EN ISO/IEC 17025 standards necessitates rigorous validation of such methods.
• Previous protocols lacked detailed validation for optimal performance and contamination control.

Purpose of the Study:

• To validate the Berlese-funnel technique for the isolation of Thrips palmi for EN ISO/IEC 17025 accreditation.
• To optimize key parameters including funnel cleaning, temperature, detection limit, and isolation duration.
• To ensure reliable and accurate detection of quarantine insects in plant samples.

Main Methods:

• Validation of the Berlese-funnel technique using Thrips fuscipennis as the target organism.
• Testing on artificially contaminated maple leaves and naturally infected rosehip.
• Investigation of parameters: cleaning procedures, bulb wattage (40W vs. 60W) for temperature control, isolation duration, and detection limits.

Main Results:

• Thrips and other organisms can persist in funnels, necessitating thorough cleaning between samples.
• A 60-watt bulb is required to achieve optimal isolation temperatures (average 35.74–39.38°C).
• An isolation period of 20 hours is necessary for 87–95% isolation efficiency, with a detection limit of 1 thrips at 95% probability.

Conclusions:

• Effective cleaning protocols and controlled temperature (using a 60W bulb) are essential for accurate Berlese-funnel technique results.
• A 20-hour isolation period is recommended for reliable detection of Thrips palmi.
• The validated Berlese-funnel technique meets requirements for EN ISO/IEC 17025 accreditation for quarantine insect isolation.