The term Phytosanitary exists within many of the modern and old scientific terms such as: organic farming, plant protection, integrated pest management, national and international movement of plant germplasm, biosecurity, good agricultural practices and others. There are many aspects within those related terms. All those terms have common interests of which the pests' risk be avoided and the environmental health is achieved. Consequently preventive measures, precaution measures and effective testing procedures are required. The study problem is the pest Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), the Tomato leaf miner, this pest is one of the most devastating pests affecting Tomato crops worldwide. Management of T. absoluta was assessed in open-field tests (2011 and 2012) using three biorational insecticides, Azadirachtin, Bacillus thuringiensis var. kurstaki, and Beauveria bassiana, and a combination of three synthetic insecticides, Emamectin, Indoxacarb and Metaflumizone, as a control treatment. Important fact have been proved by this study that only the combination of Azadirachtin – B. thuringiensis was able to reduce the impact of Tomato leaf miner regarding to the fruit’s marketable production (as a bioassay criteria), similarly to the control treatment (no significant differences). This finding suggests that biorational insecticides are a good alternative than synthetic ones. Possible use of biorational insecticides in the management of Tomato leaf miner in organic farming system is being discussed. What had been obtained in this study (Chapter 2) demonstrated that treatment based on Azadirachtin and B. thuringiensis combination can effectively reduce T. absoluta damage on Tomato open field cultivation. However, the side effects of that combination of Azadirachtin and B. thuringiensis on Tomato leaf miner natural enemies should not be ignored. Therefore, this study has included experiments (Chapter 3,4 and 5) related to the new integrated/biological control agent predator Dicyphus maroccanus (Wagner, 1951) (Hemiptera: Miridae). Those experiments have been carried out in IVIA/ Valencia –Spain 2013. Those experiments included D. maroccanus lifecycle parameters (Chapter 3), its host and prey preferences (Chapter 4), and yet its potentials on Tomato leaf miner control T. absoluta with and without the implementation of the biorational insecticide combination of Azadirachtin and B. thuringiensis under semifield (Chapter 5). In 2008, the omnivorous predator D. maroccanus was firstly detected inhabiting Tomato crops in Valencia region (East Coast of Spain). Since then, D. maroccanus has been commonly found preying on eggs of T. absoluta in this area. In this study D. maroccanus was successfully developed by preying on eggs of E. kuehniella; however, none of D. maroccanus larvae tested was able to complete development on the plant without supplemental food. Immature development time was approximately 19.5 days for both males and females, being their immature survival of 85 %. D. maroccanus larvae consumed 267 and 312 eggs of E. kuehniella, to reach male and female adulthood, respectively. Females of D. maroccanus produced 51 larvae per female throughout their 16 days of lifecycle. The progeny sex ratio was 75.6 females/total offspring. Net reproductive rate (R0) was estimated at 34.52 ± SE 0.52 female eggs/ female, generation time (T) was 28.28 ± SE 0.13 day and the estimate of intrinsic rate of increase (rm) was 0.1254 ± SE 0.0001 females/female/day. Some of these values are pretty higher than those reported for other Mirid predators on Tomato crops like Nesidiocoris tenuis and Macrolophus pygmaeus, indicating the potential as biocontrol agent of D. maroccanus on Tomato crops in the Mediterranean Basin. Life history variables varied of D. maroccanus positively comparing with the two predator species N. tenuis and M. pygmaeus, when they prey on E. kuehniella eggs. Moreover and according to the preference’s bioassays that has been conducting in IVIA showed that; D. maroccanus has high preference to healthy Tomatoes, to Tomatoes infested with T. absoluta eggs and larvae. Most of D. maroccanus lifecycle parameters are showing the possibilities to invest that predator by adopting and then by adapting it within the IPM promising strategies for time to come. Moreover the field observations showed that there were no side effects or harm features for that predator on the Tomato crop (Mollá et al. 2009). The final chapter (Chapter 5) of this study included the D. maroccanus IPM potentials assessments to control T. absoluta under semifield condition. This experiment has included D. maroccanus (alone) in different releasing rate (high and low) and that predator establishing in high releasing rate along with the biorational insecticides combination of Azadiractine plus B. thuringiensis, other treatment included only the biorational insecticide combination of Azadiractine plus B. thuringiensis and finally the control treatment. The results approved the positive effects of: a) the treatments included D. maroccanus in T. absoluta management, b) the treatments included D. maroccanus along with the biorational insecticides combination of Azadiractine plus B. thuringiensis, c) the treatments included D. maroccanus in different releasing rates (high and low) d) the treatment t included D. maroccanus high releasing rate along with the biorational insecticides combination of Azadiractine plus B. thuringiensis and that was the best treatment among the other treatments, since this treatment had the lesser number of T. absoluta Tomato infested leaflets, and had the highest level of the efficacy. It is clearly appeared that o there will be good and promising opportunities for recruiting that predator within IPM strategies for time to come

(2014). Tomato leaf miner Tuta absoluta (Meyrick,1917) (Lepidoptera: Gelechiidae) The old and new challenge. (Tesi di dottorato, Università degli Studi di Palermo, 2014).

Tomato leaf miner Tuta absoluta (Meyrick,1917) (Lepidoptera: Gelechiidae) The old and new challenge

ABBAS, Sadek
2014-02-18

Abstract

The term Phytosanitary exists within many of the modern and old scientific terms such as: organic farming, plant protection, integrated pest management, national and international movement of plant germplasm, biosecurity, good agricultural practices and others. There are many aspects within those related terms. All those terms have common interests of which the pests' risk be avoided and the environmental health is achieved. Consequently preventive measures, precaution measures and effective testing procedures are required. The study problem is the pest Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), the Tomato leaf miner, this pest is one of the most devastating pests affecting Tomato crops worldwide. Management of T. absoluta was assessed in open-field tests (2011 and 2012) using three biorational insecticides, Azadirachtin, Bacillus thuringiensis var. kurstaki, and Beauveria bassiana, and a combination of three synthetic insecticides, Emamectin, Indoxacarb and Metaflumizone, as a control treatment. Important fact have been proved by this study that only the combination of Azadirachtin – B. thuringiensis was able to reduce the impact of Tomato leaf miner regarding to the fruit’s marketable production (as a bioassay criteria), similarly to the control treatment (no significant differences). This finding suggests that biorational insecticides are a good alternative than synthetic ones. Possible use of biorational insecticides in the management of Tomato leaf miner in organic farming system is being discussed. What had been obtained in this study (Chapter 2) demonstrated that treatment based on Azadirachtin and B. thuringiensis combination can effectively reduce T. absoluta damage on Tomato open field cultivation. However, the side effects of that combination of Azadirachtin and B. thuringiensis on Tomato leaf miner natural enemies should not be ignored. Therefore, this study has included experiments (Chapter 3,4 and 5) related to the new integrated/biological control agent predator Dicyphus maroccanus (Wagner, 1951) (Hemiptera: Miridae). Those experiments have been carried out in IVIA/ Valencia –Spain 2013. Those experiments included D. maroccanus lifecycle parameters (Chapter 3), its host and prey preferences (Chapter 4), and yet its potentials on Tomato leaf miner control T. absoluta with and without the implementation of the biorational insecticide combination of Azadirachtin and B. thuringiensis under semifield (Chapter 5). In 2008, the omnivorous predator D. maroccanus was firstly detected inhabiting Tomato crops in Valencia region (East Coast of Spain). Since then, D. maroccanus has been commonly found preying on eggs of T. absoluta in this area. In this study D. maroccanus was successfully developed by preying on eggs of E. kuehniella; however, none of D. maroccanus larvae tested was able to complete development on the plant without supplemental food. Immature development time was approximately 19.5 days for both males and females, being their immature survival of 85 %. D. maroccanus larvae consumed 267 and 312 eggs of E. kuehniella, to reach male and female adulthood, respectively. Females of D. maroccanus produced 51 larvae per female throughout their 16 days of lifecycle. The progeny sex ratio was 75.6 females/total offspring. Net reproductive rate (R0) was estimated at 34.52 ± SE 0.52 female eggs/ female, generation time (T) was 28.28 ± SE 0.13 day and the estimate of intrinsic rate of increase (rm) was 0.1254 ± SE 0.0001 females/female/day. Some of these values are pretty higher than those reported for other Mirid predators on Tomato crops like Nesidiocoris tenuis and Macrolophus pygmaeus, indicating the potential as biocontrol agent of D. maroccanus on Tomato crops in the Mediterranean Basin. Life history variables varied of D. maroccanus positively comparing with the two predator species N. tenuis and M. pygmaeus, when they prey on E. kuehniella eggs. Moreover and according to the preference’s bioassays that has been conducting in IVIA showed that; D. maroccanus has high preference to healthy Tomatoes, to Tomatoes infested with T. absoluta eggs and larvae. Most of D. maroccanus lifecycle parameters are showing the possibilities to invest that predator by adopting and then by adapting it within the IPM promising strategies for time to come. Moreover the field observations showed that there were no side effects or harm features for that predator on the Tomato crop (Mollá et al. 2009). The final chapter (Chapter 5) of this study included the D. maroccanus IPM potentials assessments to control T. absoluta under semifield condition. This experiment has included D. maroccanus (alone) in different releasing rate (high and low) and that predator establishing in high releasing rate along with the biorational insecticides combination of Azadiractine plus B. thuringiensis, other treatment included only the biorational insecticide combination of Azadiractine plus B. thuringiensis and finally the control treatment. The results approved the positive effects of: a) the treatments included D. maroccanus in T. absoluta management, b) the treatments included D. maroccanus along with the biorational insecticides combination of Azadiractine plus B. thuringiensis, c) the treatments included D. maroccanus in different releasing rates (high and low) d) the treatment t included D. maroccanus high releasing rate along with the biorational insecticides combination of Azadiractine plus B. thuringiensis and that was the best treatment among the other treatments, since this treatment had the lesser number of T. absoluta Tomato infested leaflets, and had the highest level of the efficacy. It is clearly appeared that o there will be good and promising opportunities for recruiting that predator within IPM strategies for time to come
18-feb-2014
Tomato leaf miner; Azadirachtin; Bacillus thuringiensis; Beauveria bassiana; Dicyphus maroccanus
(2014). Tomato leaf miner Tuta absoluta (Meyrick,1917) (Lepidoptera: Gelechiidae) The old and new challenge. (Tesi di dottorato, Università degli Studi di Palermo, 2014).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/101523
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