Persistence and virulence of promising entomopathogenic fungal isolates for use in citrus orchards in South Africa
- Coombes, Candice A, Hill, Martin P, Moore, Sean D, Dames, Joanna F, Fullard, T
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F , Fullard, T
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416893 , vital:71394 , xlink:href="https://doi.org/10.1080/09583157.2013.819489"
- Description: Thaumatotibia leucotreta (Meyrick) (1912) (Lepidoptera: Tortricidae) is a key economic pest of citrus in South Africa. Although a variety of control options are available, none currently registered target the soil-dwelling life stages of the pest. Three fungal isolates, two Metarhizium anisopliae sensu lato Metschnikoff (Sorokin) isolates (G 11 3 L6 and FCM Ar 23 B3) and one Beauveria bassiana sensu lato Balsamo (Vuillemin) isolate (G Ar 17 B3) have been identified as showing the greatest potential against T. leucotreta soil-dwelling life stages. Since environmental persistence is an important factor in the success of entomopathogenic fungi against soil pests, the isolates, along with two commercial isolates (B. bassiana Eco-Bb® and M. anisopliae ICIPE 69), were subjected to a six-month field persistence trial. Every month after burial of the fungal isolates, inside net bags, in orchard soil, the number of colony forming units (CFUs) per gram of soil was measured and the viability of the conidia was assessed using bioassays. All isolates investigated were capable of persisting in the soil for the duration of the trial period and in addition, were capable of initiating infection in T. leucotreta late fifth instar larvae and subsequent pupae. However, with the exception of the commercial isolates which showed some correlation, no correlation was found between the number of CFUs recorded and percentage T. leucotreta mycosis. Persistence of entomopathogenic fungi in the field is affected by a series of factors, and although the effect of these factors was not measured, the data have provided preliminary evidence towards the persistence capability of these candidate biopesticides against T. leucotreta.
- Full Text:
- Date Issued: 2013
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F , Fullard, T
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416893 , vital:71394 , xlink:href="https://doi.org/10.1080/09583157.2013.819489"
- Description: Thaumatotibia leucotreta (Meyrick) (1912) (Lepidoptera: Tortricidae) is a key economic pest of citrus in South Africa. Although a variety of control options are available, none currently registered target the soil-dwelling life stages of the pest. Three fungal isolates, two Metarhizium anisopliae sensu lato Metschnikoff (Sorokin) isolates (G 11 3 L6 and FCM Ar 23 B3) and one Beauveria bassiana sensu lato Balsamo (Vuillemin) isolate (G Ar 17 B3) have been identified as showing the greatest potential against T. leucotreta soil-dwelling life stages. Since environmental persistence is an important factor in the success of entomopathogenic fungi against soil pests, the isolates, along with two commercial isolates (B. bassiana Eco-Bb® and M. anisopliae ICIPE 69), were subjected to a six-month field persistence trial. Every month after burial of the fungal isolates, inside net bags, in orchard soil, the number of colony forming units (CFUs) per gram of soil was measured and the viability of the conidia was assessed using bioassays. All isolates investigated were capable of persisting in the soil for the duration of the trial period and in addition, were capable of initiating infection in T. leucotreta late fifth instar larvae and subsequent pupae. However, with the exception of the commercial isolates which showed some correlation, no correlation was found between the number of CFUs recorded and percentage T. leucotreta mycosis. Persistence of entomopathogenic fungi in the field is affected by a series of factors, and although the effect of these factors was not measured, the data have provided preliminary evidence towards the persistence capability of these candidate biopesticides against T. leucotreta.
- Full Text:
- Date Issued: 2013
Subterranean control of an arboreal pest: EPNs and EPFs for FCM
- Moore, Sean D, Coombes, Candice A, Manrakhan, Aruna, Kirkman, Wayne, Hill, Martin P, Ehlers, Ralf-Udo, Daneel, John-Henry, De Waal, Jeanne, Dames, Joanna F, Malan, Antoinette P
- Authors: Moore, Sean D , Coombes, Candice A , Manrakhan, Aruna , Kirkman, Wayne , Hill, Martin P , Ehlers, Ralf-Udo , Daneel, John-Henry , De Waal, Jeanne , Dames, Joanna F , Malan, Antoinette P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425450 , vital:72241 , xlink:href="https://www.cabdirect.org/cabdirect/abstract/20133257699"
- Description: Control measures against the false codling moth (FCM), Thaumatotibia leucotreta, have traditionally ignored the soil-borne pupal stage. Recent trials with entomopathogenic nematodes (EPNs) and entomopathogenic fungi (EPFs) have targeted this life-stage. Application of Heterorhabditis bacteriophora to a citrus orchard floor, reduced T. leucotreta infestation of fruit by up to 81%. Conservation of H. zealandica through non-usage of a nematicide also resulted in dramatically lower fruit infestation. Dose-response and exposure time-response bioassays identified the three most promising fungal isolates against pupating T. leucotreta. Orchard trials showed persistence of these fungi in orchard soil for at least six months.
- Full Text:
- Date Issued: 2013
- Authors: Moore, Sean D , Coombes, Candice A , Manrakhan, Aruna , Kirkman, Wayne , Hill, Martin P , Ehlers, Ralf-Udo , Daneel, John-Henry , De Waal, Jeanne , Dames, Joanna F , Malan, Antoinette P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425450 , vital:72241 , xlink:href="https://www.cabdirect.org/cabdirect/abstract/20133257699"
- Description: Control measures against the false codling moth (FCM), Thaumatotibia leucotreta, have traditionally ignored the soil-borne pupal stage. Recent trials with entomopathogenic nematodes (EPNs) and entomopathogenic fungi (EPFs) have targeted this life-stage. Application of Heterorhabditis bacteriophora to a citrus orchard floor, reduced T. leucotreta infestation of fruit by up to 81%. Conservation of H. zealandica through non-usage of a nematicide also resulted in dramatically lower fruit infestation. Dose-response and exposure time-response bioassays identified the three most promising fungal isolates against pupating T. leucotreta. Orchard trials showed persistence of these fungi in orchard soil for at least six months.
- Full Text:
- Date Issued: 2013
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