VATIS UPDATE Article

A team of researchers from USDA ARS Southeastern Fruit and Tree Nut Research, Kansas State University, and Douglas Products, the United States, evaluated the efficacy of sulfuryl fluoride (SF, 99.8% purity) for the control of fourth instar pecan weevil, Curculio caryae (Horn) at 25 °C for a 24 hour exposure. Weevil larvae were collected as they naturally emerged from pecans harvested in late September, 2015.

Larvae were maintained on moistened toweling in an environment chamber at 7.2 °C and no light before processing. To infest a pecan, a weevil was placed inside a microcentrifuge tube containing 4% agar gel and capped with a dental wick. The tube was placed though the cut end of a previously prepared, empty pecan shell. A glass microscope cover slip was glued to the pecan shell opening to seal it.

For each replicate, at least 30 infested pecans in a burlap bag were fumigated with SF in a modified 3.8 L glass fumigation container. Each treatment was replicated four times. The SF concentration in each fumigation container was analyzed using GC/MS at 30 min. after SF introduction and prior to termination of the fumigation at 24 h. For the dose-response trial there were five target SF dosage treatments, ranging from 150-750 g-h/m3, and non-fumigated controls.