Detection of irradiated Bactrocera tryoni
Laboratory studies have been carried out in Australia on detection of irradiated Bactrocera tryoni (EPPO A1 quarantine pest). For quarantine purposes, a dose of 75 Gray has been recommended but it does not produce an immediate mortality of all larval stages exposed (though 100 % mortality will be reached at pupation). Therefore, it is needed to know whether live insects found within commodities at the point of import have been irradiated or not. Protein profiles for control and irradiated larvae have been compared but were found similar, so this method was not considered suitable. Another method based on anatomical comparison showed that the size of the supraesophageal ganglion is significantly reduced in irradiated larvae, and the size reduction is more important for samples which have been treated at early stages. The authors concluded that this method could be successfully used to detect B. tryoni irradiated at quarantine dose rates.
Sources
Lescano, H.G.; Congdon, B.C.; Heather, N.W. (1994) Comparison of two potential methods to detect Bactrocera tryoni (Diptera: Tephritidae) gamma-irradiated for quarantine purposes.
Journal of Economic Entomology, 87 (5), 1256-1261.