INFLUENCE OF TEMPERATURE AND CTP ON FLOUR BEETLE EGGS AFTER SULFURYL FUORIDE FUMIGATION

For European and French millers, the ban of methyl and the loss of dichlorvos (DDVP) are very problematic to disinfest their structures. Currently, sulfuryl fluoride (ProFume®, DowAgrosciences) is the only fumigant registered since 2006 for flour mills fumigation in France. This gas began to be used at commercial scale in 2007. However, the main drawback of this compound, compared with methyl bromide, is the ovicide efficacy which needs much more gas than the 20 g/m3 of methyl bromide used in France before its withdrawal. The most tolerant life stage of flour beetles. with sulfuryl fluoride is the egg stage (Bell et al, 1998), that’s why it is necessary to make flour mill’s fumigations with dosages higher than those used for MB. This kind of practice can be expensive for millers and the cost of the fumigation is quite often a barrier to the use of ProFume®. However, there is a huge difference between the dosages which ensure to control post embryonic stages of insect pests, and those able to kill the egg stage, particularly eggs of flour beetles. Moreover