The Experts below are selected from a list of 4977 Experts worldwide ranked by ideXlab platform
Des E. Conlong - One of the best experts on this subject based on the ideXlab platform.
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Stable Isotope Markers Differentiate between Mass-Reared and Wild Lepidoptera in Sterile Insect Technique Programs
Florida Entomologist, 2016Co-Authors: Rebecca Hood-nowotny, Ally Harari, Rakesh Kumar Seth, Suk-ling Wee, Des E. Conlong, David M. Suckling, Bill Woods, Kaouthar Lebdi-grissa, Gregory S. Simmons, James E. CarpenterAbstract:Abstract In this study we identified a number of moth (Lepidoptera) species that are potential targets for the Sterile Insect Technique (SIT), and we assessed the feasibility of using stable isotope signatures as markers to distinguish mass-reared from wild moth species. Large natural differences in the isotopic signatures of commercially available sugars render them novel markers for mass-reared Insects. Sugar beet (Beta vulgaris L.; Caryophyllales: Amaranthaceae), a C3 plant, has a stable isotopic signature (a measure of the ratio of the stable isotopes 13C:12C) of around -27‰ relative to Vienna Pee Dee Belemnite (VPDB; the international C isotope standard for the stable isotopes, 13C and 12C), and sugarcane (Saccharum spp.; Poales: Poaceae), a C4 plant, has an isotopic signature of around -11‰. Thus by means of such a distinct isotope ratio in the sugar in the diet, mass-reared Insects can be easily distinguished from wild Insects with a high degree of certainty. It was shown that the method could be e...
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a reaction diffusion model for the control of eldana saccharina walker in sugarcane using the Sterile Insect Technique
Ecological Modelling, 2013Co-Authors: L. Potgieter, Jh Van Vuuren, Des E. ConlongAbstract:Abstract A reaction–diffusion model is formulated for the population dynamics of an Eldana saccharina Walker infestation of sugarcane under the influence of partially Sterile released Insects. The model describes the population growth of and interaction between normal and Sterile E. saccharina moths in a temporally variable and spatially heterogeneous environment. It consists of a discretized reaction–diffusion system with variable diffusion coefficients, subject to strictly positive initial data and zero-flux Neumann boundary conditions on a bounded spatial domain. The primary objectives are to establish a model which may be used within an area-wide integrated pest management programme for E. saccharina in order to investigate the efficiency of different Sterile moth release strategies without having to conduct formal field experiments, and to present guidelines according to which release ratios, release frequencies and spatial distributions of releases may be estimated which are expected to lead to suppression of the pest. Although many reaction–diffusion models have been formulated in the literature describing the Sterile Insect Technique, few of these models describe the Technique for Lepidopteran species with more than one life stage and where F1-sterility is relevant. In addition, none of these models consider the Technique when fully Sterile females and partially Sterile males are released. The model formulated here is also the first reaction–diffusion model formulated describing E. saccharina growth and migration, and the Sterile Insect Technique applied specifically to E. saccharina .
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A reaction–diffusion model for the control of Eldana saccharina Walker in sugarcane using the Sterile Insect Technique
Ecological Modelling, 2013Co-Authors: L. Potgieter, Jh Van Vuuren, Des E. ConlongAbstract:Abstract A reaction–diffusion model is formulated for the population dynamics of an Eldana saccharina Walker infestation of sugarcane under the influence of partially Sterile released Insects. The model describes the population growth of and interaction between normal and Sterile E. saccharina moths in a temporally variable and spatially heterogeneous environment. It consists of a discretized reaction–diffusion system with variable diffusion coefficients, subject to strictly positive initial data and zero-flux Neumann boundary conditions on a bounded spatial domain. The primary objectives are to establish a model which may be used within an area-wide integrated pest management programme for E. saccharina in order to investigate the efficiency of different Sterile moth release strategies without having to conduct formal field experiments, and to present guidelines according to which release ratios, release frequencies and spatial distributions of releases may be estimated which are expected to lead to suppression of the pest. Although many reaction–diffusion models have been formulated in the literature describing the Sterile Insect Technique, few of these models describe the Technique for Lepidopteran species with more than one life stage and where F1-sterility is relevant. In addition, none of these models consider the Technique when fully Sterile females and partially Sterile males are released. The model formulated here is also the first reaction–diffusion model formulated describing E. saccharina growth and migration, and the Sterile Insect Technique applied specifically to E. saccharina .
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Modelling the effects of the Sterile Insect Technique applied to Eldana saccharina Walker in sugarcane
ORiON, 2012Co-Authors: L. Potgieter, Jh Van Vuuren, Des E. ConlongAbstract:A mathematical model is formulated for the population dynamics of an Eldana saccharina Walker infestation of sugarcane under the influence of partially Sterile released Insects. The model describes the population growth of and interaction between normal and Sterile E.saccharina moths in a temporally variable, but spatially homogeneous environment. The model consists of a deterministic system of difference equations subject to strictly positive initial data. The primary objective of this model is to determine suitable parameters in terms of which the above population growth and interaction may be quantified and according to which E.saccharina infestation levels and the associated sugarcane damage may be measured. Although many models have been formulated in the past describing the Sterile Insect Technique, few of these models describe the Technique for Lepidopteran species with more than one life stage and where F1-sterility is relevant. In addition, none of these models consider the Technique when fully Sterile females and partially Sterile males are being released. The model formulated is also the first to describe the Technique applied specifically to E.saccharina, and to consider the economic viability of applying the Technique to this species. Pertinent decision support is provided to farm managers in terms of the best timing for releases, release ratios and release frequencies.
Marc J B Vreysen - One of the best experts on this subject based on the ideXlab platform.
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phased conditional approach for mosquito management using Sterile Insect Technique
Trends in Parasitology, 2020Co-Authors: Jérémy Bouyer, Hanano Yamada, Rui Pereira, Kostas Bourtzis, Marc J B VreysenAbstract:Mosquito-borne diseases represent a major threat to humankind. Recently, the incidence of malaria has stopped decreasing while that of dengue is increasing exponentially. Alternative mosquito-control methods are urgently needed. The Sterile Insect Technique (SIT) has seen significant developments recently and may play an important role. However, testing and implementing SIT for vector control is challenging, and a phased conditional approach (PCA) is recommended, that is, advancement to the next phase depends on completion of activities in the previous one. We herewith present a PCA to test the SIT against mosquitoes within an area-wide-integrated pest-management programme, taking into account the experience gained with plant and livestock pests and the recent developments of the Technique against mosquitoes.
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Mass-Rearing of Drosophila suzukii for Sterile Insect Technique Application: Evaluation of Two Oviposition Systems
Insects, 2019Co-Authors: Fabiana Sassù, Rui Pereira, Marc J B Vreysen, Katerina Nikolouli, Silvana Caravantes, Gustavo Taret, Christian Stauffer, Carlos CáceresAbstract:Drosophila suzukii (Diptera: Drosophilidae) is an invasive pest of a wide range of commercial soft-skinned fruits. To date, most management tactics are based on spraying of conventional and/or organic Insecticides, baited traps, and netting exclusion. Interest has been expressed in using the Sterile Insect Technique (SIT) as part of area-wide integrated pest management (AW-IPM) programs to control D. suzukii infestations. Mass-rearing protocols are one of the prerequisites for successful implementation of the SIT. To establish mass-rearing methods for this species, two different egg-collection systems were developed and compared with respect to the number of eggs produced, egg viability, pupa and adult recovery, adult emergence rate, and flight ability. Female flies kept in cages equipped with a wax panel produced significantly more eggs with higher viability and adult emergence rate, as compared to the netted oviposition system. The wax panel system was also more practical and less laborious regarding the collection of eggs. Furthermore, the wax panel oviposition system can be adapted to any size or design of an adult cage. In conclusion, this system bears great promise as an effective system for the mass production of D. suzukii for SIT.
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back to the future the Sterile Insect Technique against mosquito disease vectors
Current opinion in insect science, 2015Co-Authors: Rosemary Susan Lees, Jorge Hendrichs, Marc J B Vreysen, Jeremie R L Gilles, Kostas BourtzisAbstract:With the global burden of mosquito-borne diseases increasing, and some conventional vector control tools losing effectiveness, the Sterile Insect Technique (SIT) is a potential new tool in the arsenal. Equipment and protocols have been developed and validated for efficient mass-rearing, irradiation and release of Aedines and Anophelines that could be useful for several control approaches. Assessment of male quality is becoming more sophisticated, and several groups are well advanced in pilot site selection and population surveillance. It will not be long before SIT feasibility has been evaluated in various settings. Until perfect sexing mechanisms exist, combination of Wolbachia -induced phenotypes, such as cytoplasmic incompatibility and pathogen interference, and irradiation may prove to be the safest solution for population suppression.
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Current status and future challenges for controlling malaria with the Sterile Insect Technique: technical and social perspectives
Acta Tropica, 2014Co-Authors: Clelia F. Oliva, Marc J B Vreysen, Jeremie R L Gilles, Sandrine Dupé, Rosemary S. Lees, Louis C. Gouagna, Rethy ChhemAbstract:The intolerable burden of malaria, when faced with high levels of drug resistance, increasing Insecticide resistance and meagre resources at the national level, remains a great public health challenge to governments and the research/control community. Efficient control methods against the vectors of malaria are desperately needed. Control strategies for malaria that integrate the transfer of Sterile sperm by released males to wild virgin females with other control tactics are currently being developed, and optimised mass-rearing, irradiation and release Techniques are being validated in several field sites. However, the success of this strategy as part of wider pest control or health management programmes strongly depends on gaining public understanding and acceptance. Here we attempt to review what progress has been made and the remaining challenges surrounding the use of the Sterile Insect Technique against malaria from technical and social perspectives.
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Improved quality management to enhance the efficacy of the Sterile Insect Technique for lepidopteran pests
Journal of Applied Entomology, 2010Co-Authors: Gregory S. Simmons, David M. Suckling, James E. Carpenter, V. A. Dyck, M. F. Addison, Marc J B VreysenAbstract:Lepidoptera are among the most severe pests of food and fibre crops in the world and are mainly controlled using broad spectrum Insecticides. This does not lead to environmentally sustainable control and farmers are demanding alternative control tools which are both effective and friendly to the environment. The Sterile Insect Technique (SIT), within an area-wide integrated pest management (AW-IPM) approach, has proven to be a powerful control tactic for the creation of pest-free areas or areas of low pest prevalence. Improving the quality of laboratory-reared moths would increase the efficacy of released Sterile moths applied in AW-IPM programmes that integrate the (SIT). Factors that might affect the quality and field performance of released Sterile moths are identified and characterized in this study. Some tools and methods to measure, predict and enhance moth quality are described such as tests for moth quality, female moth trapping systems, ‘smart’ traps, machine vision for recording behaviour, marking Techniques, and release technologies. Methods of enhancing rearing systems are discussed with a view to selecting and preserving useful genetic traits that improve field
Kostas Bourtzis - One of the best experts on this subject based on the ideXlab platform.
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phased conditional approach for mosquito management using Sterile Insect Technique
Trends in Parasitology, 2020Co-Authors: Jérémy Bouyer, Hanano Yamada, Rui Pereira, Kostas Bourtzis, Marc J B VreysenAbstract:Mosquito-borne diseases represent a major threat to humankind. Recently, the incidence of malaria has stopped decreasing while that of dengue is increasing exponentially. Alternative mosquito-control methods are urgently needed. The Sterile Insect Technique (SIT) has seen significant developments recently and may play an important role. However, testing and implementing SIT for vector control is challenging, and a phased conditional approach (PCA) is recommended, that is, advancement to the next phase depends on completion of activities in the previous one. We herewith present a PCA to test the SIT against mosquitoes within an area-wide-integrated pest-management programme, taking into account the experience gained with plant and livestock pests and the recent developments of the Technique against mosquitoes.
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Optimization of irradiation dose to Aedes aegypti and Ae. Albopictus in a Sterile Insect Technique program
PloS one, 2019Co-Authors: J. Guillermo Bond, Adriana R. Osorio, Nancy Avila, Yeudiel Gómez-simuta, Carlos F. Marina, Ildefonso Fernández-salas, Pablo Liedo, Ariane Dor, Danilo O. Carvalho, Kostas BourtzisAbstract:The Sterile Insect Technique (SIT) may offer a means to control the transmission of mosquito borne diseases. SIT involves the release of male Insects that have been sterilized by exposure to ionizing radiation. We determined the effects of different doses of radiation on the survival and reproductive capacity of local strains of Aedes aegypti and Ae. albopictus in southern Mexico. The survival of irradiated pupae was invariably greater than 90% and did not differ significantly in either sex for either species. Irradiation had no significant adverse effects on the flight ability (capacity to fly out of a test device) of male mosquitoes, which consistently exceeded 91% in Ae. aegypti and 96% in Ae. albopictus. The average number of eggs laid per female was significantly reduced in Ae. aegypti at doses of 15 and 30 Gy and no eggs were laid by females that had been exposed to 50 Gy. Similarly, in Ae. albopictus, egg production was reduced at doses of 15 and 25 Gy and was eliminated at 35 Gy. In Ae. aegypti, fertility in males was eliminated at 70 Gy and was eliminated at 30 Gy in females, whereas in Ae. albopictus, the fertility of males that mated with untreated females was almost zero (0.1%) in the 50 Gy treatment and female fertility was eliminated at 35 Gy. Irradiation treatments resulted in reduced ovary length and fewer follicles in both species. The adult median survival time of both species was reduced by irradiation in a dose-dependent manner. However, sterilizing doses of 35 Gy and 50 Gy resulted in little reduction in survival times of males of Ae. albopictus and Ae. aegypti, respectively, indicating that these doses should be suitable for future evaluations of SIT-based control of these species. The results of the present study will be applied to studies of male sexual competitiveness and to stepwise evaluations of the Sterile Insect Technique for population suppression of these vectors in Mexico.
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Medfly Gut Microbiota and Enhancement of the Sterile Insect Technique: Similarities and Differences of Klebsiella oxytoca and Enterobacter sp. AA26 Probiotics during the Larval and Adult Stages of the VIENNA 8D53+ Genetic Sexing Strain.
Frontiers in microbiology, 2017Co-Authors: Georgios A. Kyritsis, Carlos Cáceres, Antonios A. Augustinos, Kostas BourtzisAbstract:The Mediterranean fruit fly, Ceratitis capitata, is a major agricultural pest worldwide. The development of genetic sexing strains for this species that allows male-only Sterile Insects releases has boosted the effectiveness of the environmental friendly pest control method known as the Sterile Insect Technique. The last generation of these strains, the VIENNA 7 and VIENNA 8, are currently used in all mass rearing facilities worldwide and are considered as models for such pest control applications. The Sterile Insect Technique depends on the rearing of sufficient numbers of adequate “biological quality” laboratory flies to be released in the field. Currently, there is an increasing amount of studies focusing on the characterization of the symbiotic communities and development of probiotic diets. In our study, two bacterial isolates, an Enterobacter sp. (strain AA26) and a Klebsiella oxytoca strain, were used as probiotics in larval and adult diet. These strains have been shown to be beneficial, affecting several aspects related to the rearing efficiency and biological quality of the medfly VIENNA 8D53+ genetic sexing strain. Our results demonstrate the effect of Klebsiella oxytoca on the developmental duration of the immature stages and, to some extent, on flight ability. On the other hand, our study does not support the presence of any beneficial effect of a) Klebsiella oxytoca on pupal and adult recovery and adults’ survival under stress conditions when provided as a larval diet supplement and b) Klebsiella oxytoca and Enterobacter sp. AA26 on mating competitiveness when provided as adult diet supplements. Possible explanations for inconsistencies with previous studies and the need for universalizing protocols are discussed. Our findings, combined with previous studies can support the Sterile Insect Technique, through the improvement of different aspects of mass rearing and biological properties of laboratory reared Insect pests.
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back to the future the Sterile Insect Technique against mosquito disease vectors
Current opinion in insect science, 2015Co-Authors: Rosemary Susan Lees, Jorge Hendrichs, Marc J B Vreysen, Jeremie R L Gilles, Kostas BourtzisAbstract:With the global burden of mosquito-borne diseases increasing, and some conventional vector control tools losing effectiveness, the Sterile Insect Technique (SIT) is a potential new tool in the arsenal. Equipment and protocols have been developed and validated for efficient mass-rearing, irradiation and release of Aedines and Anophelines that could be useful for several control approaches. Assessment of male quality is becoming more sophisticated, and several groups are well advanced in pilot site selection and population surveillance. It will not be long before SIT feasibility has been evaluated in various settings. Until perfect sexing mechanisms exist, combination of Wolbachia -induced phenotypes, such as cytoplasmic incompatibility and pathogen interference, and irradiation may prove to be the safest solution for population suppression.
Ernst A. Wimmer - One of the best experts on this subject based on the ideXlab platform.
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Perspective on the combined use of an independent transgenic sexing and a multifactorial reproductive sterility system to avoid resistance development against transgenic Sterile Insect Technique approaches
BMC Genetics, 2014Co-Authors: Kolja N. Eckermann, Stefan Dippel, Mohammad Karaminejadranjbar, Hassan M. M. Ahmed, Ingrid Curril, Ernst A. WimmerAbstract:Background The Sterile Insect Technique (SIT) is an accepted species-specific genetic control approach that acts as an Insect birth control measure, which can be improved by biotechnological engineering to facilitate its use and widen its applicability. First transgenic Insects carrying a single killing system have already been released in small scale trials. However, to evade resistance development to such transgenic approaches, completely independent ways of transgenic killing should be established and combined.
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Insect Transgenesis and the Sterile Insect Technique
Insect Biotechnology, 2010Co-Authors: Marc F Schetelig, Ernst A. WimmerAbstract:The establishment of broadly applicable Insect transgenesis systems will enable the analyses of gene function in diverse Insect species. This will greatly increase our understanding of diverse aspects of biology so far not functionally addressable. Moreover, Insect transgenesis will provide novel strategies for Insect pest management and the means to impair transmission of pathogens by human disease vectors. Especially the Sterile Insect Technique (SIT) might be improved by the use of transgenic approaches. The SIT represents an effective and ecologically safe method for area-wide pest control that reduces the pest population by mass release of sterilized organisms, leading to infertile matings and in consequence to a decline of the pest population. Although the SIT is already successfully applied for some species, each of its steps – mass-rearing, sex-separation for male-only releases, sterilization, and marking for monitoring – can be improved biotechnologically to optimize the efficiency and to reduce the costs of ongoing programs or to transfer this effective Technique to a wider range of species. However, this powerful transgenic technology must be applied with great care to avoid harm to our environment.
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conditional embryonic lethality to improve the Sterile Insect Technique in ceratitis capitata diptera tephritidae
BMC Biology, 2009Co-Authors: Marc F Schetelig, Carlos E Caceres, Antigone Zacharopoulou, Gerald Franz, Ernst A. WimmerAbstract:Background The Sterile Insect Technique (SIT) is an environment-friendly method used in area-wide pest management of the Mediterranean fruit fly Ceratitis capitata (Wiedemann; Diptera: Tephritidae). Ionizing radiation used to generate reproductive sterility in the mass-reared populations before release leads to reduction of competitiveness.
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conditional embryonic lethality to improve the Sterile Insect Technique in ceratitis capitata diptera tephritidae
BMC Biology, 2009Co-Authors: Marc F Schetelig, Carlos E Caceres, Antigone Zacharopoulou, Gerald Franz, Ernst A. WimmerAbstract:The Sterile Insect Technique (SIT) is an environment-friendly method used in area-wide pest management of the Mediterranean fruit fly Ceratitis capitata (Wiedemann; Diptera: Tephritidae). Ionizing radiation used to generate reproductive sterility in the mass-reared populations before release leads to reduction of competitiveness. Here, we present a first alternative reproductive sterility system for medfly based on transgenic embryonic lethality. This system is dependent on newly isolated medfly promoter/enhancer elements of cellularization-specifically-expressed genes. These elements act differently in expression strength and their ability to drive lethal effector gene activation. Moreover, position effects strongly influence the efficiency of the system. Out of 60 combinations of driver and effector construct integrations, several lines resulted in larval and pupal lethality with one line showing complete embryonic lethality. This line was highly competitive to wildtype medfly in laboratory and field cage tests. The high competitiveness of the transgenic lines and the achieved 100% embryonic lethality causing reproductive sterility without the need of irradiation can improve the efficacy of operational medfly SIT programs.
L. Potgieter - One of the best experts on this subject based on the ideXlab platform.
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a reaction diffusion model for the control of eldana saccharina walker in sugarcane using the Sterile Insect Technique
Ecological Modelling, 2013Co-Authors: L. Potgieter, Jh Van Vuuren, Des E. ConlongAbstract:Abstract A reaction–diffusion model is formulated for the population dynamics of an Eldana saccharina Walker infestation of sugarcane under the influence of partially Sterile released Insects. The model describes the population growth of and interaction between normal and Sterile E. saccharina moths in a temporally variable and spatially heterogeneous environment. It consists of a discretized reaction–diffusion system with variable diffusion coefficients, subject to strictly positive initial data and zero-flux Neumann boundary conditions on a bounded spatial domain. The primary objectives are to establish a model which may be used within an area-wide integrated pest management programme for E. saccharina in order to investigate the efficiency of different Sterile moth release strategies without having to conduct formal field experiments, and to present guidelines according to which release ratios, release frequencies and spatial distributions of releases may be estimated which are expected to lead to suppression of the pest. Although many reaction–diffusion models have been formulated in the literature describing the Sterile Insect Technique, few of these models describe the Technique for Lepidopteran species with more than one life stage and where F1-sterility is relevant. In addition, none of these models consider the Technique when fully Sterile females and partially Sterile males are released. The model formulated here is also the first reaction–diffusion model formulated describing E. saccharina growth and migration, and the Sterile Insect Technique applied specifically to E. saccharina .
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A reaction–diffusion model for the control of Eldana saccharina Walker in sugarcane using the Sterile Insect Technique
Ecological Modelling, 2013Co-Authors: L. Potgieter, Jh Van Vuuren, Des E. ConlongAbstract:Abstract A reaction–diffusion model is formulated for the population dynamics of an Eldana saccharina Walker infestation of sugarcane under the influence of partially Sterile released Insects. The model describes the population growth of and interaction between normal and Sterile E. saccharina moths in a temporally variable and spatially heterogeneous environment. It consists of a discretized reaction–diffusion system with variable diffusion coefficients, subject to strictly positive initial data and zero-flux Neumann boundary conditions on a bounded spatial domain. The primary objectives are to establish a model which may be used within an area-wide integrated pest management programme for E. saccharina in order to investigate the efficiency of different Sterile moth release strategies without having to conduct formal field experiments, and to present guidelines according to which release ratios, release frequencies and spatial distributions of releases may be estimated which are expected to lead to suppression of the pest. Although many reaction–diffusion models have been formulated in the literature describing the Sterile Insect Technique, few of these models describe the Technique for Lepidopteran species with more than one life stage and where F1-sterility is relevant. In addition, none of these models consider the Technique when fully Sterile females and partially Sterile males are released. The model formulated here is also the first reaction–diffusion model formulated describing E. saccharina growth and migration, and the Sterile Insect Technique applied specifically to E. saccharina .
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Modelling the effects of the Sterile Insect Technique applied to Eldana saccharina Walker in sugarcane
ORiON, 2012Co-Authors: L. Potgieter, Jh Van Vuuren, Des E. ConlongAbstract:A mathematical model is formulated for the population dynamics of an Eldana saccharina Walker infestation of sugarcane under the influence of partially Sterile released Insects. The model describes the population growth of and interaction between normal and Sterile E.saccharina moths in a temporally variable, but spatially homogeneous environment. The model consists of a deterministic system of difference equations subject to strictly positive initial data. The primary objective of this model is to determine suitable parameters in terms of which the above population growth and interaction may be quantified and according to which E.saccharina infestation levels and the associated sugarcane damage may be measured. Although many models have been formulated in the past describing the Sterile Insect Technique, few of these models describe the Technique for Lepidopteran species with more than one life stage and where F1-sterility is relevant. In addition, none of these models consider the Technique when fully Sterile females and partially Sterile males are being released. The model formulated is also the first to describe the Technique applied specifically to E.saccharina, and to consider the economic viability of applying the Technique to this species. Pertinent decision support is provided to farm managers in terms of the best timing for releases, release ratios and release frequencies.
