title: Partial Cold Treatment of Citrus Fruit for Export Risk Mitigation for Thaumatotibia leucotreta (Lepidoptera: Tortricidae) as Part of a Systems Approach.
abstract: Some of South Africa's citrus export markets require mandatory postharvest cold treatment of citrus fruit as a phytosanitary risk mitigation treatment for Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). An alternative to this may be partial cold treatment as one of the final steps in a systems approach to mitigate phytosanitary risk. Consequently, the efficacy of such partial cold treatments was evaluated. It was first determined that a 2°C cold treatment was significantly more effective against fourth and fifth instars (the most cold-tolerant instars) than treatments at 3°C and 4°C for a duration of 18 d. Secondly, it was determined that 2°C for 18 d and 1°C for 16 d were similarly effective, but both treatments were significantly more effective than 1°C for 14 d. Mean mortality of fourth and fifth instars treated with 2°C for 18 d in seven replicates from four trials was 99.94%. Finally, it was determined that the inability of the majority of surviving larvae to develop to adulthood would further increase the efficacy of a 2°C for 18 d treatment to 99.96%. Inclusion of reproductive nonviability of survivors increased mortality to 99.99%.
authors.affiliation: Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (seanmoore@cri.co.za; wk@cri.co.za) Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa (sonnicavn@gmail.com; claire.natalie.love@gmail.com) seanmoore@cri.co.za.
authors.forename: S D
authors.initials: SD
authors.lastname: Moore
authors.affiliation: Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (seanmoore@cri.co.za; wk@cri.co.za).
authors.forename: W
authors.initials: W
authors.lastname: Kirkman
authors.affiliation: Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa (sonnicavn@gmail.com; claire.natalie.love@gmail.com).
authors.forename: S
authors.initials: S
authors.lastname: Albertyn
authors.affiliation: Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa (sonnicavn@gmail.com; claire.natalie.love@gmail.com).
authors.forename: C N
authors.initials: CN
authors.lastname: Love
authors.affiliation: Deparment of Botany, Rhodes University, PO Box 94, Grahamstown 6140, South Africa (julie.coetzee@ru.ac.za), and.
authors.forename: J A
authors.initials: JA
authors.lastname: Coetzee
authors.affiliation: Citrus Research International, Department of Horticultural Sciences, Stellenbosch University, Victoria Street, Stellenbosch 7602, South Africa (vh@cri.co.za).
authors.forename: V
authors.initials: V
authors.lastname: Hattingh
mesh_terms: D000818:Animals; D002957:Citrus / Q000502:physiology*; D005638:Fruit / Q000502:physiology; D007300:Insect Control / Q000379:methods*; D007814:Larva / Q000254:growth & development / Q000502:physiology; D009036:Moths / Q000254:growth & development / Q000502:physiology*; D010572:Pest Control, Biological / Q000379:methods*; D013019:South Africa; D013597:Systems Analysis
keywords: South Africa; artificial diet; false codling moth; mortality; viability