Phytosanitary treatment of packed table grapes against insects and mites
The effect of a treatment for packed table grapes, using a combination of low temperature storage and slow release of sulfur dioxide pads against Platynota stultana (Lepidoptera: Tortricidae - EPPO Alert List), was studied in the laboratory and in a large-scale commercial test. The effect of this treatment against other pests such as Frankliniella occidentalis (Thysanoptera: Thripidae - EPPO A2 quarantine pest), Pseudococcus maritimus (Homoptera: Pseudococcidae), Tetranychus pacificus and T. urticae (Acari: Tetranychidae) was assessed. Temperatures within foam containers (50 cm wide x 50 cm long x 17 cm high) decreased from ambient to 2°C in one day, and then ranged from 0.4 to 1.7°C in both tests. Sulfur dioxide concentrations in the foam containers ranged from 0.2 to 1.6 ppm during the 1 to 6 weeks storage period in the laboratory test, and from 0.5 to 1.1 ppm in the 1 to 8 weeks storage period of the large scale tests. Laboratory tests showed that F. occidentalis was completely killed within one week, that P. maritimus was completely killed after 6 weeks, and that 98% and 99.6% mortality was obtained for T. pacificus and T. urticae, respectively. In the large scale test, after 8 weeks of exposure, mortality reached 100% for P. stultana, F. occidentalis and T. urticae. Less than 8% survival was obtained for P. maritimus and less than 1% for T. pacificus. The authors concluded that this combined treatment could be very useful as a quarantine treatment against several insects and mites. In particular, it could be applied during ocean transport of commodities.
Sources
Yokoyama, V.Y.; Miller, G.T.; Crisosto, C.H. (2001) Pest response in packed table grapes to low temperatures storage combined with slow-release sulfur dioxide pads in basic and large-scale tests.
Journal of Economic Entomology 94(4), 984-988.