Comparing the Use of Laboratory-Reared and Field-CollectedThaumatotibia leucotreta(Lepidoptera: Tortricidae) Larvae for Demonstrating Efficacy of Postharvest Cold Treatments in Citrus Fruit
| Autor: | V. Hattingh, Sean D. Moore, S. Albertyn, Wayne Kirkman |
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| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
Tortricidae Citrus animal structures Moths Biology medicine.disease_cause Insect Control 01 natural sciences Lepidoptera genitalia South Africa parasitic diseases Infestation Botany medicine Animals Pest Control Biological Phytosanitary certification Larva Ecology fungi food and beverages General Medicine biology.organism_classification 010602 entomology Horticulture Fruit Insect Science Postharvest False codling moth 010606 plant biology & botany Citrus fruit |
| Zdroj: | Journal of Economic Entomology. 109:1571-1577 |
| ISSN: | 1938-291X 0022-0493 |
| Popis: | Some of South Africa's export markets require postharvest cold treatment of citrus fruit for phytosanitary risk mitigation for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). An alternative to a standalone cold treatment may be a reduced intensity cold treatment as a step in a systems approach. For cold treatment trials, large numbers of larvae are required. Due to recent dramatic improvement of T. leucotreta control in the field, sufficient naturally infested citrus fruit are no longer available. Artificial infestation of fruit is not viable due to rapid decay of the fruit. Consequently, it is necessary to use laboratory-reared T. leucotreta larvae in artificial diet. In trials, field-collected larvae from the Eastern Cape were at least as cold-tolerant as those from other regions. Larvae in Navel oranges showed the median level of susceptibility in a range of citrus types evaluated at 6°C, and their use in trials was considered acceptable due to their greater natural susceptibility to T. leucotreta infestation. We demonstrated that larvae at high density in artificial diet were at least as cold-tolerant as larvae at lower densities. When exposed to 2°C for 18 d or longer, larvae in artificial diet as used in the trials were at least as cold-tolerant as larvae in fruit. Very few surviving larvae from fruit completed development, with no subsequent generation. Consequently, it is considered justifiable to conduct cold-treatment trials with laboratory-reared T. leucotreta larvae in artificial diet without risk of overestimating the effect of cold on feral larvae in citrus fruit. [corrected] |
| Databáze: | OpenAIRE |
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