2024-12-22-OECD-半野外条件下蜜蜂育雏试验的指导文件_第二版（英）_38页_1mb

Summary of the Guidance Document on the Honey Bee (Apis Mellifera L.) Brood Test Under Semi-field Conditions, Second Edition

Core Content

This document provides a semi-field test method for assessing the adverse effects of pesticides and other chemicals on honey bee brood (eggs, larvae, and pupae) under conditions that more closely resemble real-world exposure scenarios. It is intended to complement existing laboratory-based tests (OECD TG 237 and GD 239) and is particularly relevant for the assessment of insect growth regulators (IGRs) in the European Union.

The test is designed to evaluate the impact on brood development and colony performance, including adult bee mortality, foraging activity, behavioural abnormalities, and overall colony development. The test method has been validated using a reference substance (fenoxycarb) and is expected to produce quantitative data at the colony level.

Main Points

Purpose

• To provide a semi-field method for the quantitative assessment of adverse effects on honey bee brood.
• To support the environmental risk assessment of pesticides and other chemicals.
• To offer a higher-tier test that simulates real-world exposure conditions more closely than laboratory-based tests.

Test Design

• The test is conducted in semi-field tunnels with a minimum area of 60 m².
• Queen-right colonies are used, with equal and comparable strength across all treatment groups.
• The test includes three treatment groups:
  • Test chemical
  • Water-treated negative control
  • Reference substance-treated positive control (e.g., fenoxycarb)

Application

• The test chemical is typically applied at the highest labelled single application rate.
• Application timing is usually during full flowering (BBCH 63-65), but may vary depending on the type of pesticide or chemical being tested (e.g., pre-flowering, seed treatment).
• The application should be done during full bee foraging activity (daytime, when bees are actively flying and collecting nectar and pollen).

Exposure and Monitoring

• The exposure phase lasts at least 7 days after application.
• A post-exposure monitoring phase of at least 21 days follows.
• The total study duration is at least 28 days, and may be extended to 42 days if monitoring multiple brood cycles.

Assessments

• Mortality of adult bees and brood is assessed daily on linen sheets placed at the front, middle, and back of the tunnels.
• Foraging activity is monitored by counting the number of bees per m².
• Colony condition is evaluated through brood development, adult bee numbers, and brood compensation index (BCI).
• Brood Termination Rate (BTR) and Brood Index (BI) are key endpoints used to assess the impact of the test chemical.

Key Information

Advantages of the Semi-field Method

• Natural brood development within the hive.
• Realistic exposure conditions that include contact and ingestion of residues.
• Evaluation of nearly all application scenarios, including foliar, soil, seed treatment, and pre- and post-flowering applications.
• Potential use in higher-tier field studies through digital brood assessments.

Limitations

• Climate conditions (e.g., temperature, precipitation) can affect the results.
• Low or high temperatures may limit foraging activity or inhibit brood development.
• Enclosure stress (caging effect) may reduce brood numbers.
• Short exposure duration due to limited bloom time within tunnels (typically 7–10 days).
• Crops not attractive to bees are not suitable for the test.

Validity and Reporting

• The test must meet validity criteria, including consistent exposure, appropriate control groups, and data collection.
• The report should include:
  • Colony preparation and acclimatisation details.
  • Treatment application and exposure conditions.
  • Meteorological data.
  • Brood and adult bee mortality assessments.
  • Brood development and compensation index.
  • Statistical analysis of results.
  • Comparison with control and reference substance groups.

Additional Considerations

• Colony health is essential, with no signs of disease or parasites.
• Medical treatments (e.g., for Varroa mites) should be applied uniformly to all colonies.
• Supplemental feeding should be avoided during the exposure phase, unless necessary and done equally across all treatment groups.
• Water sources should be available in tunnels, with floating aids to prevent drowning.
• Wind speed should not exceed 3 m/sec outside the tunnels, and rainfall should be avoided until sprayed treatments have dried.

Conclusion

The Honey Bee Brood Test Under Semi-field Conditions is a comprehensive method for assessing the impact of pesticides on honey bee colonies, especially for insect growth regulators. It is designed to simulate real-world exposure and provides quantitative data that can be used to evaluate the ecological risks of pesticides. The test is validated and updated based on real-world data and expert recommendations, making it a reliable tool for environmental risk assessment.