In sunflower cultivations using a fipronil seed-coating treatment, the risk assessment for F. candida was evaluated considering the soil phenylpyrazoles distribution. At the end of the cultivation period, a concentration gradient was measured from the seed-coat (3.2 mg kg−1 FW) to 6 cm distance (0.08 mg kg−1 FW) (Raveton et al., 2007). Following this field study, it appeared that the risk was unacceptable near the seed (RQ < 1) because of the high local concentration of phenylpyrazoles (Table 5). Out of this restrictive zone, the risk appeared to be acceptable with RQ values >1. Nevertheless, the distribution pattern of phenylpyrazoles could move with time leading to a broader contamination zone. The risk assessment might be unacceptable in the upper soil layer (0–20 cm). However, F. candida seemed to be able to detect differences in their habitat and could choose to avoid the contaminated soil zones ( Aldaya et al., 2006). Therefore, in phenylpyrazoles contaminated soil, springtails might be able to move from one zone to another and select one or several zones according to their life cycle (nutrition, moulting and oviposition).