Meeting Abstract
Trading fresh commodities increases the risk of introducing potentially invasive pest species to new areas. One way to mitigate the risk is through phytosanitary treatments. The use of ionizing radiation as a phytosanitary treatment is growing in popularity, as it is chemical and residue-free. However, unlike traditional chemicals and fumigants, successful treatments with irradiation leave some insects alive. Although these insects will be unable to produce viable offspring and will eventually die, the presence of live insects at commodity inspection can be of concern to some trade partners. Therefore, there is a need for a diagnostic test to confirm that the insects have been irradiated, and do not pose a risk. Previous research suggests that radiation exposure can increase the amount of free/total amino acids and change the concentration of metabolites. However, there is a lack of consensus between species, and detailed investigation using modern, more sensitive, methods is warranted. To investigate whether metabolic biomarkers could be used as a diagnostic test, we exposed third instar larvae and pharate adults of Caribbean fruit fly, Anastrepha suspensa, to gamma radiation (0 to 400 Gy). At various time points after radiation, we measured amino acids and nucleotides (NAD and NADH) with Thermo Quantiva MS and Agilent 1290/6490 LC/MS/MS respectively. We report on whether radiation–induced changes in amino acid and nucleotide composition and/or concentrations can be used to identify irradiated insects.
