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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #226086
Title: Effect of radiation on fecundity and fertility of codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) from South Africa.

Author
item BLOMEFIELD, T - ARC INFRUITEC-NIETVOORBIJ
item BLOEM, S - USDA APHIS PPQ
item Carpenter, James

Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2008
Publication Date: 3/2/2009
Citation: Blomefield, T.L., Bloem, S., Carpenter, J.E. 2010. Effect of radiation on fecundity and fertility of codling moth Cydia pomonella (Linnaeus)(Lepidoptera: Tortricidae) from South Africa. Journal of Applied Entomology. 134:216-220.

Interpretive Summary: Codling moth, Cydia pomonella (L.), is the key pest of pome fruit in South Africa, and control of codling moth in apple and pear orchards relies on the application of insecticides and in some cases pheromone mediated mating disruption. Development of resistance to insecticides and placement of restrictions on the use of certain insecticides has made control of codling moth in South Africa increasingly problematic. The use of the sterile insect technique (SIT) as a control tactic for codling moth is under investigation as a potential addition to the current control strategy. We investigated the radiosensitivity of a codling moth strain in laboratory culture that was initiated from codling moths collected from conventional and organic commercial orchards in the Western Cape, South Africa. Fecundity and fertility of this strain from South Africa were consistent with the radio-sensitivity of the codling moth strain in culture at the Canadian rearing facility in British Columbia. For both the South African strain and the Canadian strain, the female codling moth was considerably more radio-sensitive than the male. At a radiation dose of 100 Gy or higher, treated females were sterile. A comparison of the fertility of our South African strain and published fertility data for the Canadian strain reveals that the level of fertility for untreated South African males (86.3%) was higher than the level of fertility for untreated Canadian males (71.9%). This difference in fertility between the two strains was maintained when the dose of radiation was 100 Gy. However, the level of fertility was very similar between the two strains for doses = 150 Gy. Therefore, based upon previously published work and the data from this study, we recommend an operational dose of 150 Gy for future codling moth SIT programs.

Technical Abstract: Codling moth, Cydia pomonella (L.), is the key pest of pome fruit in South Africa, and control of codling moth in apple and pear orchards relies on the application of insecticides and in some cases pheromone mediated mating disruption. Development of resistance to insecticides and placement of restrictions on the use of certain insecticides has made control of codling moth in South Africa increasingly problematic. The use of the sterile insect technique (SIT) as a control tactic for codling moth is under investigation as a potential addition to the current control strategy. We investigated the radiosensitivity of a codling moth strain in laboratory culture that was initiated from codling moths collected from conventional and organic commercial orchards in the Western Cape, South Africa. Fecundity and fertility of this strain from South Africa were consistent with the radio-sensitivity of the codling moth strain in culture at the Canadian rearing facility in British Columbia. For both the South African strain and the Canadian strain, the female codling moth was considerably more radio-sensitive than the male. At a radiation dose of 100 Gy or higher treated females could be considered as 100 % sterile. A comparison of the fertility of our South African strain and published fertility data for the Canadian strain reveals that the level of fertility for untreated South African males (86.3%) was higher than the level of fertility for untreated Canadian males (71.9%). This difference in fertility between the two strains was maintained when the dose of radiation was 100 Gy. However, the level of fertility was very similar between the two strains for doses = 150 Gy. Therefore, based upon previously published work and the data from this study, we recommend an operational dose of 150 Gy for future codling moth SIT programmes in South Africa.