Efficacy of sulfuryl fluoride on stored product insects in a semolina mill trial in Italy.

Abstract An experimental fumigation was undertaken in a semolina mill in Italy in July 2001 to evaluate the insecticidal activity of sulfuryl fluoride determined from laboratory chamber fumigations. The structure was sealed using rigid polycarbonate sheeting, sprayable foam, polyethylene and tape. Seventeen stored product insect bioassays were introduced throughout the mill prior to fumigation. Insect species and life stages included in the bioassays were mixed cultures of Sitophilus oryzae, Rhyzopertha dominica, Stegobium paniceum, eggs and pupae of Plodia interpunctella, Ephestia kuehniella, eggs and adults of Tribolium confusum and Tribolium castaneum. Monitoring lines to measure gas concentration were placed in close proximity to each bioassay location together with data loggers for recording temperature. The structure was fumigated for 22 h and 15 minutes, and a range of concentration × time products from 1101 to 1501 g h-1 m-3 were recorded. Following aeration of the structure, the bioassays were removed and incubated under laboratory conditions at 27°C and 70% relative humidity for mortality assessments. Insect survival was not recorded following 30 days of incubation, confirming previously determined efficacy findings from sulfuryl fluoride chamber fumigations.