Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2012
Publication Date: 4/20/2013
Citation: Yee, W.L., Chapman, P.S., Tanigoshi, L.K. 2013. Alternative fumigants to methyl bromide for killing pupae and preventing emergence of apple maggot fly (Diptera:Tephritidae). Journal of Entomological Science. 48:36-42.
Interpretive Summary: The apple maggot fly damages apple fruit and is a major quarantine concern for apple growers in the western U.S. Personnel at the USDA-ARS Yakima Agricultural Research Laboratory in Wapato, WA and the Washington State University, Northwestern Washington Research and Extension Center, Mount Vernon, WA conducted tests to identify fumigants that can be used to kill the pupae of apple maggot flies. Tests showed that chloropicrin and Telone II, both non ozone-depleting substances, killed more pupae than methyl bromide, ECO2FUME, and Vapam and prevented all adult fly emergence, whereas the other fumigants did not. This study shows that chloropicrin and Telone II could be alternative fumigants to methyl bromide for killing pupae and preventing emergence of apple maggot flies.
Technical Abstract: Effects of methyl bromide, ECO2FUME (phosphine gas + CO2), Vapam (sodium methyldithiocarbamate), chloropicrin, Telone II (1, 3 dichloropropene), and chloropicrin + Telone II on killing the pupae and preventing adult emergence of apple maggot fly, Rhagoletis pomonella (Walsh) was determined. In an experiment performed inside glass flasks, pupal mortality caused by all fumigants 7 d after a 4-h exposure was significantly higher than in the control, but effects of the five fumigants on pupal mortality 7 d post exposure did not differ consistently even though chloropicrin caused the highest absolute mortality. In contrast, fumigant effects on adult emergence were consistent and clearer in that chloropicrin, Telone II, and chloropicrin + Telone II prevented all emergence of adult flies over 111–112 d whereas methyl bromide, ECO2FUME, and Vapam reduced it by only 41–73% compared with controls. The differences in pupal mortality and adult emergence patterns suggest that the fumigants acted slowly. This is the first study that shows chloropicrin, Telone II, and the two in combination could be alternative fumigants to methyl bromide for killing pupae and preventing emergence of R. pomonella.