4.2.8. Comparison of impacts

1) The use of the control and the toxic reference provides predictable impacts to which the impact of the test pesticide can be compared. Mortality is standard and predictable in the control though the foraging activity to the flowering crop may vary with climatic conditions.

2) Colony strength and development (measured per Delaplane et al., 2013b) should be similar at the beginning and end of the experimental phase under the tunnel.

3) On the contrary, the reference dimethoate 400 g AI/ha induces a high mortality the day after application and continues for several days. During the same time, the count of forager bees (see section 4.2.4.) drops to zero because of the pesticide’s high repellent effect.