Objective of the study

Semi-field tests (involving cages, tunnels or tents) and field tests (conducted in open (large) fields) are higher-tier studies that may be triggered if lower tier tests indicate a possible risk of the pesticide to honeybees, if there are concerns about systemic activity, or if the product has insect growth regulator (IGR) properties. Semi-field testing can be modified for specific assessments with honeybees, e.g. repellency and other behavioural effects, effects of aged residues, evaluation of the hazard of applying plant protection products to honeybees foraging the honeydew secreted by aphids, or specific testing of brood effects. In semi-field studies, honeybees from small colonies are forced to forage on a flowering crop in field cages; this is intended to provide realistic worst-case exposure. In field studies, honeybee colonies are generally placed in or on the edge of large fields of flowering crops, which are chosen so that bees are exposed mainly to the flowering field in which the hives are placed.

Circumstances under which the study is recommended to be required

Semi-field and field studies may be required if lower tier tests indicate a possible risk to honeybees.

Test organism

The study is are normally conducted with (small) honeybee colonies.

Test substance

End-use product

Typical endpoints of the study

Specific endpoints of semi-field and field studies depend on the study objectives, and may include:

• Adult mortality
• Brood development
• Brood termination-rate
• Adult behaviour
• Flight and⁄or foraging activity
• Comb areas with pollen and nectar
• Comb areas containing eggs, larvae and capped cells
• Overall health of the test colonies (including brood status)

Test guidelines

The following test guidelines may be used for semi-field and field studies with honeybees:

• OECD Series on Testing and Assessment. Number 75: Guidance document on the honey bee (Apis mellifera L.) brood test under semi-field conditions.
• US EPA Ecological Effects Test Guidelines. 850.3040: Field testing for pollinators.
• EPPO Standard PP1/170 (4): Test methods for evaluating the side-effects of plant protection products on honeybees.
• COLOSS BEEBOOK Vol I: Standard methods for toxicology research in Apis mellifera.
• EFSA Guidance document on the risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees. Appendix O: Effect studies – protocols, guidance and guidelines for honey bee, bumble bee and solitary bee.