Irradiation treatments for Conotrachelus nenuphar, Maconellicoccus hirsutus and fruit flies
Research was done in USA to develop a phytosanitary irradiation treatment against Conotrachelus nenuphar (Coleoptera: Curculionidae – EPPO A1 list). Results showed that adults were the most resistant stage, and that the dose recommended as a quarantine treatment, which would prevent adults from reproducing, is 92 Gy. It was also noted that hosts of C. nenuphar (e.g. Malus, Prunus, Vaccinium) would tolerate such a dose (Hallman, 2003).
Studies were done in USA on the tolerance of Maconellicoccus hirsutus (Homoptera: Pseudococcidae – EPPO A1 list) to irradiation, in order to determine the dose needed to disinfect commodities. Adults were the most resistant stage. At 100 Gy, adults were still able to produce a small number of viable eggs (1.2%), which gave rise to individuals able to produce progeny. At 250 Gy, all adults were controlled and no eggs hatched. It is concluded that the minimum dose needed to ensure phytosanitary security is between 100 and 250 Gy. Further research is still needed to determine the lowest effective dose (Jacobsen & Hara, 2003).
Studies were done in Mexico to determine the minimum irradiation dose required to prevent adult emergence of the following fruit fly species infesting mangoes: Anastrepha ludens, A. obliqua, A. serpentina (Diptera Tephritidae – EPPO A1 list) and Ceratitis capitata (EPPO A2 list). Mangoes infested with third instar larvae (most resistant stage) were irradiated at various doses. Results showed that a dose of 150 Gy could be recommended to ensure phytosanitary security. A minor decrease in the ascorbic acid content was the only adverse effect observed in irradiated mangoes (Bustos et al., 2004).
Sources
Bustos, M.E; Enkerlin, W.; Reyes, J.; Toledo, J. (2004) Irradiation of mangoes as a postharvest quarantine treatment for fruit flies (Diptera: Tephritidae).
Journal of Economic Entomology, 97(2), 286-292.
Hallman, G.J. (2003) Ionizing irradiation quarantine treatment against plum curculio (Coleoptera: Curculionidae).
Journal of Economic Entomology, 96(5), 1399-1404.
Jacobsen, C.M.; Hara, A.H. (2003) Irradiation of Maconellicoccus hirsutus (Homoptera: Pseudococcidae) for phytosanitation of agricultural commodities.
Journal of Economic Entomology, 96(4), 1134-1339.