The Experts below are selected from a list of 4188 Experts worldwide ranked by ideXlab platform
Francis Frédéric - One of the best experts on this subject based on the ideXlab platform.
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Overview of Bruchus rufimanus Boheman 1833 (Coleoptera: Chrysomelidae): Biology, chemical ecology and semiochemical opportunities in integrated pest management programs
'Elsevier BV', 2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:peer reviewedaudience: researcher, professional, student, popularizationPromoting the cultivation of native legumes, such as faba beans (Vicia faba L.) within the European Union is anticipated to contribute to the sustainability of cropping systems and provide food and feed proteins as alternatives to unsustainable imports. However, efficient alternative control methods to pesticides must be implemented to combat key pests that devalue faba bean seeds (namely, Bruchus rufimanus Boheman 1833, Coleoptera: Chrysomelidae). This pest causes significant economic losses in faba bean crops as post-embryonic development (cf. seminovorous larvae) occurs inside forming seeds. While there has been extensive research on the biology and chemical ecology of B. rufimanus, efficient control methods are lacking. Here, we review this pest species to identify: (i) knowledge gaps on its biology that could enhance management tools; (ii) potential improvements to current semiochemical based control approaches; and (iii) other method of control based on Semiochemicals that could be implemented.FEVERPR
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FEVERPRO Project Development of biological control methods in alternative to pesticides to manage Bruchus rufimanus Boheman 1833 in field bean crops
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:peer reviewedaudience: researcher, professional, student, popularizationBruchus rufimanus Boheman 1833 (Coleoptera : Chrysomelidae) is a serious pest of Vicia faba L. (Fabaceae) preventing the valuation of crop products due to its post-embryonic development taking place inside forming seeds. However, the European Union, concerned about the sustainable development of its agriculture, promotes V. faba crops for its multiple services provided to cropping systems, and restricts at the same time the use of effective pesticides against B. rufimanus. This suggests the finding of alternative control methods, such as the use of Semiochemicals. To date, some volatile organic compounds (VOCs) involved in the field colonization, feeding, mating and oviposition of B. rufimanus, taking place on different parts of V. faba and following its phenological stage, have already been identified. Further studies would, however, provide insight into other pheromonal means of communication that could be implemented in the semiochemical-based management of this pest, such as the assessment of oviposition or aggregation pheromones. Concerning the semiochemical-based control methods, only one study has been trying to implement a mass-trapping method; and no studies investigated other methods, such as the push-pull or attract-and-kill methods, in IPM strategy including new insight into pheromone identification, entomopathogenic agents or specific parasitoids. In this context, preliminary experimentations of entomopathogenic tests and odor samplings for the identification of new pheromones (aggregation or oviposition deterring pheromone) were carried out within the “FEVERPRO project”, and could suggest the implementation of innovative control methods of this specific pest in alternative to the use of pesticides.FEVERPR
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Overview of Bruchus rufimanus Boheman 1833 (Coleoptera: Chrysomelidae): Biology, chemical ecology and semiochemical opportunities in integrated pest management programs
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:Promoting the cultivation of native legumes, such as faba beans (Vicia faba L.) within the European Union is anticipated to contribute to the sustainability of cropping systems and provide food and feed proteins as alternatives to unsustainable imports. However, efficient alternative control methods to pesticides must be implemented to combat key pests that devalue faba bean seeds (namely, Bruchus rufimanus Boheman 1833, Coleoptera: Chrysomelidae). This pest causes significant economic losses in faba bean crops as post-embryonic development (cf. seminovorous larvae) occurs inside forming seeds. While there has been extensive research on the biology and chemical ecology of B. rufimanus, efficient control methods are lacking. Here, we review this pest species to identify: (i) knowledge gaps on its biology that could enhance management tools; (ii) potential improvements to current semiochemical based control approaches; and (iii) other method of control based on Semiochemicals that could be implemented.Peer reviewe
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FEVERPRO Project Development of biological control methods in alternative to pesticides to manage Bruchus rufimanus Boheman 1833 in field bean crops
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:Bruchus rufimanus Boheman 1833 (Coleoptera : Chrysomelidae) is a serious pest of Vicia faba L. (Fabaceae) preventing the valuation of crop products due to its post-embryonic development taking place inside forming seeds. However, the European Union, concerned about the sustainable development of its agriculture, promotes V. faba crops for its multiple services provided to cropping systems, and restricts at the same time the use of effective pesticides against B. rufimanus. This suggests the finding of alternative control methods, such as the use of Semiochemicals. To date, some volatile organic compounds (VOCs) involved in the field colonization, feeding, mating and oviposition of B. rufimanus, taking place on different parts of V. faba and following its phenological stage, have already been identified. Further studies would, however, provide insight into other pheromonal means of communication that could be implemented in the semiochemical-based management of this pest, such as the assessment of oviposition or aggregation pheromones. Concerning the semiochemical-based control methods, only one study has been trying to implement a mass-trapping method; and no studies investigated other methods, such as the push-pull or attract-and-kill methods, in IPM strategy including new insight into pheromone identification, entomopathogenic agents or specific parasitoids. In this context, preliminary experimentations of entomopathogenic tests and odor samplings for the identification of new pheromones (aggregation or oviposition deterring pheromone) were carried out within the “FEVERPRO project”, and could suggest the implementation of innovative control methods of this specific pest in alternative to the use of pesticides.Peer reviewe
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Bacteria may contribute to distant species recognition in ant–aphid mutualistic relationships
2016Co-Authors: Fischer Christophe, Francis Frédéric, Verheggen François, Haubruge Eric, Thonart Philippe, Detrain Claire, Lognay GeorgesAbstract:Mutualistic interactions between ant and aphid species have been the subject of considerable historical and contemporary investigations, the primary benefits being cleaning and protection for the aphids and carbohydrate-rich honeydew for the ants. Questions remained, however, as to the volatile semiochemical factor influencing this relationship. A recent study highlighted the role of bacterial honeydew volatile compounds in ant attraction. Here, ant’s ability to distantly discriminate two aphid species was investigated based on bacterial honeydew Semiochemicals emissions using a two-way olfactometer. Both the mutualistic black bean aphid (Aphis fabae L.) and the non-myrmecophilous pea aphid (Acyrthosiphon pisum Harris) were found to be attractive for the black garden ant (Lasius niger L.). The level of attraction was similar in both assays (control versus one of the aphid species). However, when given a choice between these two aphid species, ants showed a significant preference for Aphis fabae. Honeydew volatiles, mostly from bacterial origins, are known to be a key element in ant attraction. Using the same olfactometry protocol, the relative attractiveness of volatiles emitted by honeydews collected from each aphid species and by bacteria isolated from each honeydew was in investigated. Again, ants significantly preferred volatiles released by Aphis fabae honeydew and bacteria. This information suggests that microbial honeydew volatiles enable ants to distantly discriminate aphid species. These results emphasize the importance of investigating the presence and potential effects of microbes in insect symbioses.Peer reviewe
Lognay Georges - One of the best experts on this subject based on the ideXlab platform.
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Overview of Bruchus rufimanus Boheman 1833 (Coleoptera: Chrysomelidae): Biology, chemical ecology and semiochemical opportunities in integrated pest management programs
'Elsevier BV', 2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:peer reviewedaudience: researcher, professional, student, popularizationPromoting the cultivation of native legumes, such as faba beans (Vicia faba L.) within the European Union is anticipated to contribute to the sustainability of cropping systems and provide food and feed proteins as alternatives to unsustainable imports. However, efficient alternative control methods to pesticides must be implemented to combat key pests that devalue faba bean seeds (namely, Bruchus rufimanus Boheman 1833, Coleoptera: Chrysomelidae). This pest causes significant economic losses in faba bean crops as post-embryonic development (cf. seminovorous larvae) occurs inside forming seeds. While there has been extensive research on the biology and chemical ecology of B. rufimanus, efficient control methods are lacking. Here, we review this pest species to identify: (i) knowledge gaps on its biology that could enhance management tools; (ii) potential improvements to current semiochemical based control approaches; and (iii) other method of control based on Semiochemicals that could be implemented.FEVERPR
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FEVERPRO Project Development of biological control methods in alternative to pesticides to manage Bruchus rufimanus Boheman 1833 in field bean crops
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:peer reviewedaudience: researcher, professional, student, popularizationBruchus rufimanus Boheman 1833 (Coleoptera : Chrysomelidae) is a serious pest of Vicia faba L. (Fabaceae) preventing the valuation of crop products due to its post-embryonic development taking place inside forming seeds. However, the European Union, concerned about the sustainable development of its agriculture, promotes V. faba crops for its multiple services provided to cropping systems, and restricts at the same time the use of effective pesticides against B. rufimanus. This suggests the finding of alternative control methods, such as the use of Semiochemicals. To date, some volatile organic compounds (VOCs) involved in the field colonization, feeding, mating and oviposition of B. rufimanus, taking place on different parts of V. faba and following its phenological stage, have already been identified. Further studies would, however, provide insight into other pheromonal means of communication that could be implemented in the semiochemical-based management of this pest, such as the assessment of oviposition or aggregation pheromones. Concerning the semiochemical-based control methods, only one study has been trying to implement a mass-trapping method; and no studies investigated other methods, such as the push-pull or attract-and-kill methods, in IPM strategy including new insight into pheromone identification, entomopathogenic agents or specific parasitoids. In this context, preliminary experimentations of entomopathogenic tests and odor samplings for the identification of new pheromones (aggregation or oviposition deterring pheromone) were carried out within the “FEVERPRO project”, and could suggest the implementation of innovative control methods of this specific pest in alternative to the use of pesticides.FEVERPR
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Overview of Bruchus rufimanus Boheman 1833 (Coleoptera: Chrysomelidae): Biology, chemical ecology and semiochemical opportunities in integrated pest management programs
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:Promoting the cultivation of native legumes, such as faba beans (Vicia faba L.) within the European Union is anticipated to contribute to the sustainability of cropping systems and provide food and feed proteins as alternatives to unsustainable imports. However, efficient alternative control methods to pesticides must be implemented to combat key pests that devalue faba bean seeds (namely, Bruchus rufimanus Boheman 1833, Coleoptera: Chrysomelidae). This pest causes significant economic losses in faba bean crops as post-embryonic development (cf. seminovorous larvae) occurs inside forming seeds. While there has been extensive research on the biology and chemical ecology of B. rufimanus, efficient control methods are lacking. Here, we review this pest species to identify: (i) knowledge gaps on its biology that could enhance management tools; (ii) potential improvements to current semiochemical based control approaches; and (iii) other method of control based on Semiochemicals that could be implemented.Peer reviewe
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FEVERPRO Project Development of biological control methods in alternative to pesticides to manage Bruchus rufimanus Boheman 1833 in field bean crops
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:Bruchus rufimanus Boheman 1833 (Coleoptera : Chrysomelidae) is a serious pest of Vicia faba L. (Fabaceae) preventing the valuation of crop products due to its post-embryonic development taking place inside forming seeds. However, the European Union, concerned about the sustainable development of its agriculture, promotes V. faba crops for its multiple services provided to cropping systems, and restricts at the same time the use of effective pesticides against B. rufimanus. This suggests the finding of alternative control methods, such as the use of Semiochemicals. To date, some volatile organic compounds (VOCs) involved in the field colonization, feeding, mating and oviposition of B. rufimanus, taking place on different parts of V. faba and following its phenological stage, have already been identified. Further studies would, however, provide insight into other pheromonal means of communication that could be implemented in the semiochemical-based management of this pest, such as the assessment of oviposition or aggregation pheromones. Concerning the semiochemical-based control methods, only one study has been trying to implement a mass-trapping method; and no studies investigated other methods, such as the push-pull or attract-and-kill methods, in IPM strategy including new insight into pheromone identification, entomopathogenic agents or specific parasitoids. In this context, preliminary experimentations of entomopathogenic tests and odor samplings for the identification of new pheromones (aggregation or oviposition deterring pheromone) were carried out within the “FEVERPRO project”, and could suggest the implementation of innovative control methods of this specific pest in alternative to the use of pesticides.Peer reviewe
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Bacteria may contribute to distant species recognition in ant–aphid mutualistic relationships
2016Co-Authors: Fischer Christophe, Francis Frédéric, Verheggen François, Haubruge Eric, Thonart Philippe, Detrain Claire, Lognay GeorgesAbstract:Mutualistic interactions between ant and aphid species have been the subject of considerable historical and contemporary investigations, the primary benefits being cleaning and protection for the aphids and carbohydrate-rich honeydew for the ants. Questions remained, however, as to the volatile semiochemical factor influencing this relationship. A recent study highlighted the role of bacterial honeydew volatile compounds in ant attraction. Here, ant’s ability to distantly discriminate two aphid species was investigated based on bacterial honeydew Semiochemicals emissions using a two-way olfactometer. Both the mutualistic black bean aphid (Aphis fabae L.) and the non-myrmecophilous pea aphid (Acyrthosiphon pisum Harris) were found to be attractive for the black garden ant (Lasius niger L.). The level of attraction was similar in both assays (control versus one of the aphid species). However, when given a choice between these two aphid species, ants showed a significant preference for Aphis fabae. Honeydew volatiles, mostly from bacterial origins, are known to be a key element in ant attraction. Using the same olfactometry protocol, the relative attractiveness of volatiles emitted by honeydews collected from each aphid species and by bacteria isolated from each honeydew was in investigated. Again, ants significantly preferred volatiles released by Aphis fabae honeydew and bacteria. This information suggests that microbial honeydew volatiles enable ants to distantly discriminate aphid species. These results emphasize the importance of investigating the presence and potential effects of microbes in insect symbioses.Peer reviewe
Segers Arnaud - One of the best experts on this subject based on the ideXlab platform.
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Overview of Bruchus rufimanus Boheman 1833 (Coleoptera: Chrysomelidae): Biology, chemical ecology and semiochemical opportunities in integrated pest management programs
'Elsevier BV', 2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:peer reviewedaudience: researcher, professional, student, popularizationPromoting the cultivation of native legumes, such as faba beans (Vicia faba L.) within the European Union is anticipated to contribute to the sustainability of cropping systems and provide food and feed proteins as alternatives to unsustainable imports. However, efficient alternative control methods to pesticides must be implemented to combat key pests that devalue faba bean seeds (namely, Bruchus rufimanus Boheman 1833, Coleoptera: Chrysomelidae). This pest causes significant economic losses in faba bean crops as post-embryonic development (cf. seminovorous larvae) occurs inside forming seeds. While there has been extensive research on the biology and chemical ecology of B. rufimanus, efficient control methods are lacking. Here, we review this pest species to identify: (i) knowledge gaps on its biology that could enhance management tools; (ii) potential improvements to current semiochemical based control approaches; and (iii) other method of control based on Semiochemicals that could be implemented.FEVERPR
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FEVERPRO Project Development of biological control methods in alternative to pesticides to manage Bruchus rufimanus Boheman 1833 in field bean crops
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:peer reviewedaudience: researcher, professional, student, popularizationBruchus rufimanus Boheman 1833 (Coleoptera : Chrysomelidae) is a serious pest of Vicia faba L. (Fabaceae) preventing the valuation of crop products due to its post-embryonic development taking place inside forming seeds. However, the European Union, concerned about the sustainable development of its agriculture, promotes V. faba crops for its multiple services provided to cropping systems, and restricts at the same time the use of effective pesticides against B. rufimanus. This suggests the finding of alternative control methods, such as the use of Semiochemicals. To date, some volatile organic compounds (VOCs) involved in the field colonization, feeding, mating and oviposition of B. rufimanus, taking place on different parts of V. faba and following its phenological stage, have already been identified. Further studies would, however, provide insight into other pheromonal means of communication that could be implemented in the semiochemical-based management of this pest, such as the assessment of oviposition or aggregation pheromones. Concerning the semiochemical-based control methods, only one study has been trying to implement a mass-trapping method; and no studies investigated other methods, such as the push-pull or attract-and-kill methods, in IPM strategy including new insight into pheromone identification, entomopathogenic agents or specific parasitoids. In this context, preliminary experimentations of entomopathogenic tests and odor samplings for the identification of new pheromones (aggregation or oviposition deterring pheromone) were carried out within the “FEVERPRO project”, and could suggest the implementation of innovative control methods of this specific pest in alternative to the use of pesticides.FEVERPR
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Overview of Bruchus rufimanus Boheman 1833 (Coleoptera: Chrysomelidae): Biology, chemical ecology and semiochemical opportunities in integrated pest management programs
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:Promoting the cultivation of native legumes, such as faba beans (Vicia faba L.) within the European Union is anticipated to contribute to the sustainability of cropping systems and provide food and feed proteins as alternatives to unsustainable imports. However, efficient alternative control methods to pesticides must be implemented to combat key pests that devalue faba bean seeds (namely, Bruchus rufimanus Boheman 1833, Coleoptera: Chrysomelidae). This pest causes significant economic losses in faba bean crops as post-embryonic development (cf. seminovorous larvae) occurs inside forming seeds. While there has been extensive research on the biology and chemical ecology of B. rufimanus, efficient control methods are lacking. Here, we review this pest species to identify: (i) knowledge gaps on its biology that could enhance management tools; (ii) potential improvements to current semiochemical based control approaches; and (iii) other method of control based on Semiochemicals that could be implemented.Peer reviewe
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FEVERPRO Project Development of biological control methods in alternative to pesticides to manage Bruchus rufimanus Boheman 1833 in field bean crops
2020Co-Authors: Segers Arnaud, Caparros Megido Rudy, Lognay Georges, Francis FrédéricAbstract:Bruchus rufimanus Boheman 1833 (Coleoptera : Chrysomelidae) is a serious pest of Vicia faba L. (Fabaceae) preventing the valuation of crop products due to its post-embryonic development taking place inside forming seeds. However, the European Union, concerned about the sustainable development of its agriculture, promotes V. faba crops for its multiple services provided to cropping systems, and restricts at the same time the use of effective pesticides against B. rufimanus. This suggests the finding of alternative control methods, such as the use of Semiochemicals. To date, some volatile organic compounds (VOCs) involved in the field colonization, feeding, mating and oviposition of B. rufimanus, taking place on different parts of V. faba and following its phenological stage, have already been identified. Further studies would, however, provide insight into other pheromonal means of communication that could be implemented in the semiochemical-based management of this pest, such as the assessment of oviposition or aggregation pheromones. Concerning the semiochemical-based control methods, only one study has been trying to implement a mass-trapping method; and no studies investigated other methods, such as the push-pull or attract-and-kill methods, in IPM strategy including new insight into pheromone identification, entomopathogenic agents or specific parasitoids. In this context, preliminary experimentations of entomopathogenic tests and odor samplings for the identification of new pheromones (aggregation or oviposition deterring pheromone) were carried out within the “FEVERPRO project”, and could suggest the implementation of innovative control methods of this specific pest in alternative to the use of pesticides.Peer reviewe
Jason D Bals - One of the best experts on this subject based on the ideXlab platform.
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a simple cost effective emitter for controlled release of fish pheromones development testing and application to management of the invasive sea lamprey
PLOS ONE, 2018Co-Authors: Michael C Wagner, James E Hanson, Trevor D Meckley, Nicholas S Johnson, Jason D BalsAbstract:Semiochemicals that elicit species-specific attraction or repulsion have proven useful in the management of terrestrial pests and hold considerable promise for control of nuisance aquatic species, particularly invasive fishes. Because aquatic ecosystems are typically large and open, use of a semiochemical to control a spatially dispersed invader will require the development of a cost-effective emitter that is easy to produce, environmentally benign, inexpensive, and controls the release of the semiochemical without altering its structure. We examined the release properties of five polymers, and chose polyethylene glycol (PEG) as the best alternative. In a series of laboratory and field experiments, we examined the response of the invasive sea lamprey to PEG, and to a partial sex pheromone emitted from PEG that has proven effective as a trap bait to capture migrating sea lamprey prior to spawning. Our findings confirm that the sea lamprey does not behaviorally respond to PEG, and that the attractant response to the pheromone component was conserved when emitted from PEG. Further, we deployed the pheromone-PEG emitters as trap bait during typical control operations in three Great Lakes tributaries, observing similar improvements in trap performance when compared to a previous study using mechanically pumped liquid pheromone. Finally, the polymer emitters tended to dissolve unevenly in high flow conditions. We demonstrate that housing the emitter stabilizes the dissolution rate at high water velocity. We conclude the performance characteristics of PEG emitters to achieve controlled-release of a semiochemical are sufficient to recommend its use in conservation and management activities related to native and invasive aquatic organisms.
Toby J. A. Bruce - One of the best experts on this subject based on the ideXlab platform.
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aspects of insect chemical ecology exploitation of reception and detection as tools for deception of pests and beneficial insects
Physiological Entomology, 2012Co-Authors: J A Pickett, L. E. Smart, Toby J. A. Bruce, Michael A. Birkett, Gudbjorg I Aradottir, Keith Chamberlain, Zeyaur R Khan, Charles A O Midega, C M WoodcockAbstract:Empirical exploitation of insect reception and detection at the peripheral neurosensory level has been extremely valuable for identifying pheromones and other Semiochemicals, mainly by electroantennogram or single cell preparations coupled with capillary gas chromatography. Differential sensitivity to Semiochemicals at the single-cell level has allowed the identification of some of the most active Semiochemicals relating to host location and, more importantly, to the avoidance of nonhosts. However, in terms of molecular recognition, there is still a considerable gap in understanding the detection of particular molecules and their discrimination from closely-related chemical structures. New approaches will be needed to understand the processes of molecular recognition more precisely. Nevertheless, from electrophysiological studies to the most advanced molecular techniques, it has been possible to identify Semiochemicals for the deception of pests in their quest to find plant and animal hosts, as well as mates. Even the deception of insects antagonistic to pests, particularly parasitoids, can now be exploited for managing pests in more sustainable systems. Successes in exploiting insect Semiochemicals in the interests of better agriculture and animal husbandry are exemplified, and potential new ways of learning more about reception and detection for deception are discussed. This takes the subject beyond the management of pest and beneficial insects to wider commercial and social opportunities.
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development of semiochemical attractants for monitoring bean seed beetle bruchus rufimanus
Pest Management Science, 2011Co-Authors: Toby J. A. Bruce, L. E. Smart, J.l. Martin, John A. PickettAbstract:BACKGROUND:Bruchus rufimanus is a serious pest of field beans. The objective here was to develop a semiochemical-baited trapping system to facilitate monitoring of the pest. RESULTS: Volatile compounds that were electrophysiologically active with the antennae of B. rufimanus females were identified from headspace samples of Vicia faba flowers and from male B. rufimanus. Selected headspace samples and synthetic compounds were tested in olfactometer bioassays. The Semiochemicals were then formulated in lures for traps and evaluated in a field trapping experiment. Cone traps baited with a three-component blend of floral volatiles, releasing (R)-linalool (17.7 mg day−1), cinnamyl alcohol (0.4 mg day−1) and cinnamaldehyde (0.77 mg day−1), caught significantly more of both sexes of B. rufimanus than unbaited control traps. A male volatile, 1-undecene, was EAG active with female antennae. It was attractive to females in an olfactometer, indicating that it is a sex pheromone. However, in the field it only enhanced trap catches if it was released together with the floral volatiles. CONCLUSION: The blends of Semiochemicals identified were shown to be attractive in cone traps under field conditions. The prototype trapping system developed could be used as a monitoring tool to determine infestation levels of B. rufimanus in bean fields. Copyright © 2011 Society of Chemical Industry
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exploiting phytochemicals for developing a push pull crop protection strategy for cereal farmers in africa
Journal of Experimental Botany, 2010Co-Authors: Zeyaur R Khan, Toby J. A. Bruce, Charles A O Midega, Antony M Hooper, J A PickettAbstract:Lepidopteran stemborers and parasitic weeds in the genus Striga are major constraints to efficient production of cereals, the most important staple food crops in Africa. Smallholder farmers are resource constrained and unable to afford expensive chemicals for crop protection. Development of a push–pull approach for integrated pest and weed management is reviewed here. Appropriate plants were discovered that naturally emit signalling chemicals (Semiochemicals). Plants highly attractive for egg laying by stemborer pests were selected and employed as trap crops (pull), to draw pests away from the main crop. Of these, Napier grass, Pennisetum purpureum (Schumach), despite its attractiveness, supported minimal survival of the pests’ immature stages. Plants that repelled stemborer pests, notably molasses grass, Melinis minutiflora P. Beauv., and forage legumes in the genus Desmodium, were selected as intercrops (push). Desmodium intercrops suppress Striga hermonthica (Del.) Benth. through an allelopathic mechanism. Their root exudates contain novel flavonoid compounds, which stimulate suicidal germination of S. hermonthica seeds and dramatically inhibit its attachment to host roots. The companion crops provide valuable forage for farm animals while the leguminous intercrops also improve soil fertility and moisture retention. The system is appropriate as it is based on locally available plants, not expensive external inputs, and fits well with traditional mixed cropping systems in Africa. To date it has been adopted by more than 30 000 smallholder farmers in East Africa where maize yields have increased from ; 1t ha 21 to 3.5 t ha 21 . Future directions for semiochemical delivery by plants including biotechnological opportunities are discussed.
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Semiochemicals used in host location by the coffee berry borer hypothenemus hampei
Journal of Chemical Ecology, 2009Co-Authors: Esayas Mendesil, John C. Caulfield, Christine M. Woodcock, Toby J. A. Bruce, Emiru SeyoumAbstract:The coffee berry borer, Hypothenemus hampei is a serious pest in many coffee growing countries. Electrophysiological and behavioral responses of H. hampei to volatiles of different phenological stages of coffee, Coffea arabica, fruits were studied in order to identify volatile Semiochemicals used in host location. Volatiles were collected from different phenological stages of C. arabica fruit by air entrainment. Electrophysiological recordings were made from insect antennae. Behavioral assays were carried out using a Perspex four-arm olfactometer. Insects spent significantly more time in the region of the olfactometer where ripe and dry fruit volatiles were present compared to control regions. Coupled gas chromatography—electroantennography revealed the presence of six electrophysiologically active compounds in C. arabica volatiles. These were identified by using GC and GC-MS as methylcyclohexane, ethylbenzene, nonane, 1-octen-3-ol, (R)-limonene, and (R)-3-ethyl-4-methylpentanol. In the olfactometer bioassay, H. hampei showed a significant response to 3-ethyl-4-methylpentanol, methylcyclohexane, nonane, ethylbenzene, and a synthetic blend of these four compounds. Attraction to the synthetic blend was comparable to that for the natural sample. The significance of the study is discussed in terms of semiochemical based pest management methods of the coffee berry borer.