NOAEC and/or curve is generated Contact and oral exposure routes are included Larval effects are important for some MOAs (insect growth regulators) Assessment of effects through pupation is currently difficult Effects are assessed at the individual level Test is currently under development (chronic) Larval chronic (repeat dose) Adult emergence/NOAEC Foliar residue Mortality, residual toxicity and/or RT25 Contact exposure through residues on foliage Can assess pesticide residual toxicity Acute exposure only Actual dose not quantified Effects are measured at the individual level Table 5: Tier-2 – End-points, strengths and limitations of bee toxicity studies Semi field, Tunnel Colony strength Brood pattern and development Foraging activity Worker mortality and behaviour Food storage and consumption Queen health Multiple exposure routes (contact, oral) related to pesticide use methods Minimises influence of outside exposure to other chemicals Some behavioural can be quantified; Standard test protocol (OECD) Colony level effects can be related to application rate and/or residues Short term exposure only (usually 7–10 days in the tunnel) Foraging may not be natural; Stress on colonies from tunnel confinement Replication and statistical power are often low Usually based on a surrogate crop Semi field, Feeding Long term exposure can be assessed Colony level effects can be related to dietary concentration Greater replication can be achieved vs. tunnel or full field studies Greater control over exposure vs. full field studies Oral route only Consumed dose may differ from that encountered in the field Protocols have not been standardised Confounding influences of off-site foraging and exposure Foraging may not be natural Table 6: Tier-3 – End-points, strengths and limitations of bee toxicity studies Full field (experimental) Colony strength Brood pattern and development Most environmentally realistic of crop/pesticide exposure conditions Practical constraints may limit ability to assess ‘high end’ exposure scenarios
For some years, the Australian Department of the Environment has been applying a hazard classification system for bee toxicity based on that described in Mensink et al (1995). The three highest hazard classifications in this scheme are: LD50 <0.1 µg/bee Highly toxic LD50 0.1–1.0 µg/bee Toxic LD50 1.0–10 µg/bee Moderately toxic It is appropriate to maintain the rating system that has been used historically in Australia; these classifications are applied to invoke the following hazard statements on the label: Hazard-based label statements Table 11: Hazard statements based on adult acute oral and contact toxicity results >10 µg/bee No statement required 1.0–10 µg/bee Moderately toxic to bees 0.1–1.0 µg/bee Toxic to bees <0.1 µg/bee Highly toxic to bees Systemic compounds: Apiarists requested the APVMA to include information on product labels if the active constituent has a systemic mode of action. The following statement is suggested. Table 12: Statement for active constituents which have a systemic action SUGGESTED Systemic compounds <ACTIVE> has a systemic action. Risk-based label statements Even though a substance may be hazardous its use may be acceptable if exposure is unlikely to result in levels which are toxic to the organism. The following statements are designed to communicate the potential for risk to bees. Where a hazard statement is required, these risk-based statements should follow the hazard statement: Table 13: Risk statements based on risk quotients (RQs) Hazardous, but RQ <LOC The use pattern as per the Directions for Use is not expected to result in exposure to bees. SUGGESTED