It has been shown that bees can be contaminated with potentially lethal doses of insecticide simply by flying in the vicinity of a pneumatic drilling machine using seeds coated with insecticide (Marzaro et al., 2011; Girolami et al., 2012). The fragments of this coating are emitted into the atmosphere and constitute a toxic cloud the size of which may be estimated at some tens of metres in diameter. Only bees in flight were considered when reporting these observations about powdering, not bees possibly exposed to powder that fell to the ground and could contaminate on contact.

The following reported techniques presuppose an evaluation of the contamination, mortality and chemical analysis of a single bee. Once the bees are treated with powder, one must avoid the possibility that the bees in the same cage could contact and exchange contaminants, thus altering the results. For this reason, bees were kept separately one per cage. The test reports the evaluation of the acute toxicity which can cause the death of bees between 24 and 48 h and for maximum practicality should be conducted under normal laboratory conditions (see section below).