Conceptualizing, categorizing and recording the outcomes of biological control of invasive plant species, at a population level
- Hoffmann, John H, Moran, V Clifford, Hill, Martin P
- Authors: Hoffmann, John H , Moran, V Clifford , Hill, Martin P
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423315 , vital:72047 , xlink:href="https://doi.org/10.1016/j.biocontrol.2019.02.005"
- Description: Rates of establishment of agents, their population dynamics after release, and measures of the damage they inflict on their target hosts are all useful indicators of progress and success in weed biological control but cannot account for the overall degree and extent of weed biocontrol achievements (i.e. outcomes) at a plant population level. Current conventions that describe weed biocontrol outcomes as ‘negligible’, ‘partial’, ‘substantial’ or ‘complete’, are often idiosyncratic and imprecise and are inadequate for describing the complexities involved. Using selected examples from South Africa, an extension of the present system is proposed for conceptualizing and categorizing weed biocontrol outcomes more easily; it incorporates four different invasion parameters i.e. density, area, biomass and number of propagules, for different regions and habitats. This approach should help to provide weed biocontrol practitioners with a shared basis for describing, succinctly and with greater precision, the results of their weed biocontrol programs, at a plant population level.
- Full Text:
- Date Issued: 2019
- Authors: Hoffmann, John H , Moran, V Clifford , Hill, Martin P
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423315 , vital:72047 , xlink:href="https://doi.org/10.1016/j.biocontrol.2019.02.005"
- Description: Rates of establishment of agents, their population dynamics after release, and measures of the damage they inflict on their target hosts are all useful indicators of progress and success in weed biological control but cannot account for the overall degree and extent of weed biocontrol achievements (i.e. outcomes) at a plant population level. Current conventions that describe weed biocontrol outcomes as ‘negligible’, ‘partial’, ‘substantial’ or ‘complete’, are often idiosyncratic and imprecise and are inadequate for describing the complexities involved. Using selected examples from South Africa, an extension of the present system is proposed for conceptualizing and categorizing weed biocontrol outcomes more easily; it incorporates four different invasion parameters i.e. density, area, biomass and number of propagules, for different regions and habitats. This approach should help to provide weed biocontrol practitioners with a shared basis for describing, succinctly and with greater precision, the results of their weed biocontrol programs, at a plant population level.
- Full Text:
- Date Issued: 2019
Beauveria and Metarhizium against false codling moth (Lepidoptera: Tortricidae): a step towards selecting isolates for potential development of a mycoinsecticide
- 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: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405757 , vital:70203 , xlink:href="https://hdl.handle.net/10520/EJC167505"
- Description: False codling moth, Thaumatotibia leucotreta Meyrick (1912) (Lepidoptera: Tortricidae), can cause both pre- and post-harvest damage to citrus fruit. Not only can this result in reduced crop yield, but more importantly because of the moth's endemism to sub-Saharan Africa, it is classified as a phytosanitary pest by many export markets. An entire consignment of citrus may be rejected in the presence of a single moth (Moore 2012). Since the bulk of citrus fruit production in South Africa is exported, the control of T. leucotreta is critical (Citrus Growers Association, South Africa 2012). Traditionally, control has been achieved through the use of chemical insecticides; however, residue restrictions, resistance development and concerns about environmental pollution have substantially reduced the dependence on chemical pesticides in citrus. Research on T. leucotreta control has therefore focused on the use of biological organisms (e.g. parasitoids and viruses), which are used as control agents within an integrated pest management (IPM) programme in citrus. These biological control agents, however, only targeted the aboveground life stages of the pest, not the soil-dwelling life stages (late fifth instars, prepupae, pupae), which is the subject of this contribution (Moore 2012).
- Full Text:
- Date Issued: 2015
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F , Fullard, T
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405757 , vital:70203 , xlink:href="https://hdl.handle.net/10520/EJC167505"
- Description: False codling moth, Thaumatotibia leucotreta Meyrick (1912) (Lepidoptera: Tortricidae), can cause both pre- and post-harvest damage to citrus fruit. Not only can this result in reduced crop yield, but more importantly because of the moth's endemism to sub-Saharan Africa, it is classified as a phytosanitary pest by many export markets. An entire consignment of citrus may be rejected in the presence of a single moth (Moore 2012). Since the bulk of citrus fruit production in South Africa is exported, the control of T. leucotreta is critical (Citrus Growers Association, South Africa 2012). Traditionally, control has been achieved through the use of chemical insecticides; however, residue restrictions, resistance development and concerns about environmental pollution have substantially reduced the dependence on chemical pesticides in citrus. Research on T. leucotreta control has therefore focused on the use of biological organisms (e.g. parasitoids and viruses), which are used as control agents within an integrated pest management (IPM) programme in citrus. These biological control agents, however, only targeted the aboveground life stages of the pest, not the soil-dwelling life stages (late fifth instars, prepupae, pupae), which is the subject of this contribution (Moore 2012).
- Full Text:
- Date Issued: 2015
Characterisation of novel CrleGV isolates for false codling moth control-lessons learnt from codling moth resistance to CpGV. Characterisation of novel CrleGV isolates for false codling moth control-lessons learnt from codling moth resistance to CpGV
- Opoku-Debrah, John K, Moore, Sean D, Hill, Martin P, Knox, Caroline M
- Authors: Opoku-Debrah, John K , Moore, Sean D , Hill, Martin P , Knox, Caroline M
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425414 , vital:72237 , xlink:href="https://www.cabdirect.org/cabdirect/abstract/20133257674"
- Description: Recently some codling moth, Cydia pomonella, populations in Europe developed resistance to CpGV. In order to prepare for the possibility of a similar occurrence with the false codling moth, Thaumatotibia leucotreta, in South Africa, a search was conducted for novel CrleGV isolates. Through overcrowding, outbreaks of novel isolates were recorded from laboratory populations of five geographically distinct host populations. The genetic novelty of these and two commercially available isolates was confirmed through restriction enzyme analysis and sequence analysis of the granulin and egt genes. Phylogenetic analysis showed the existence of two CrleGV-SA genome types. Significant differences in virulence were also shown between certain isolates against certain host populations.
- Full Text:
- Date Issued: 2013
- Authors: Opoku-Debrah, John K , Moore, Sean D , Hill, Martin P , Knox, Caroline M
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425414 , vital:72237 , xlink:href="https://www.cabdirect.org/cabdirect/abstract/20133257674"
- Description: Recently some codling moth, Cydia pomonella, populations in Europe developed resistance to CpGV. In order to prepare for the possibility of a similar occurrence with the false codling moth, Thaumatotibia leucotreta, in South Africa, a search was conducted for novel CrleGV isolates. Through overcrowding, outbreaks of novel isolates were recorded from laboratory populations of five geographically distinct host populations. The genetic novelty of these and two commercially available isolates was confirmed through restriction enzyme analysis and sequence analysis of the granulin and egt genes. Phylogenetic analysis showed the existence of two CrleGV-SA genome types. Significant differences in virulence were also shown between certain isolates against certain host populations.
- Full Text:
- Date Issued: 2013
Is classical biological control a 20th century" old science" paradigm that is losing its way?
- Sheppard, Andy, Werner, K, Hill, Martin P, McEvoy, Peter, Fowler, Simon, Hill, Richard
- Authors: Sheppard, Andy , Werner, K , Hill, Martin P , McEvoy, Peter , Fowler, Simon , Hill, Richard
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425434 , vital:72239 , xlink:href="https://www.fs.usda.gov/research/treesearch/44754"
- Description: For years most countries accepted the benefits of biological control as given, leading to facilitated inside lanes through the regulatory maze. "Successes" led to many passionate disciples over science rationalists. Biocontrol targets continue to be selected on assumptions of good value with little direct evidence. Even when successful, biocontrol has rarely delivered environmental benefits that have been measured. Money flow is still healthy, but is arguably being directed against less impactful targets. Lack of science rigour exposes the field to attacks from an increasing number of critics as values change. A global change driven counter-revolution is underway on the dichotomy of hate between natives and aliens. Will climate change undermine even currently successful biocontrol outcomes? Meanwhile negative direct and indirect impacts of biological continue to fuel dissent. Nowhere is this issue hotter than in Hawaii where "invaders" have massively increased biodiversity, make up nearly all the biomass and create whole new ecosystems. This workshop will entertain a panel discussion around the future for classical biological control of weeds. Does it need to change its paradigm in response to changing societal values, if so can it reinvent itself?
- Full Text:
- Date Issued: 2013
- Authors: Sheppard, Andy , Werner, K , Hill, Martin P , McEvoy, Peter , Fowler, Simon , Hill, Richard
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425434 , vital:72239 , xlink:href="https://www.fs.usda.gov/research/treesearch/44754"
- Description: For years most countries accepted the benefits of biological control as given, leading to facilitated inside lanes through the regulatory maze. "Successes" led to many passionate disciples over science rationalists. Biocontrol targets continue to be selected on assumptions of good value with little direct evidence. Even when successful, biocontrol has rarely delivered environmental benefits that have been measured. Money flow is still healthy, but is arguably being directed against less impactful targets. Lack of science rigour exposes the field to attacks from an increasing number of critics as values change. A global change driven counter-revolution is underway on the dichotomy of hate between natives and aliens. Will climate change undermine even currently successful biocontrol outcomes? Meanwhile negative direct and indirect impacts of biological continue to fuel dissent. Nowhere is this issue hotter than in Hawaii where "invaders" have massively increased biodiversity, make up nearly all the biomass and create whole new ecosystems. This workshop will entertain a panel discussion around the future for classical biological control of weeds. Does it need to change its paradigm in response to changing societal values, if so can it reinvent itself?
- Full Text:
- Date Issued: 2013
Morphological and genetic characterization of a South African Plutella xylostella granulovirus (plxy GV) isolate
- Abdulkadir, Fatima, Marsberg, Tamryn, Knox, Caroline M, Hill, Martin P, Moore, Sean D
- Authors: Abdulkadir, Fatima , Marsberg, Tamryn , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406117 , vital:70240 , xlink:href="https://hdl.handle.net/10520/EJC132828"
- Description: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar and Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.
- Full Text:
- Date Issued: 2013
- Authors: Abdulkadir, Fatima , Marsberg, Tamryn , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406117 , vital:70240 , xlink:href="https://hdl.handle.net/10520/EJC132828"
- Description: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar and Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.
- Full Text:
- Date Issued: 2013
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