Tephritid fruit flies are considered one of the world’s most notorious pests of horticultural crops, including mango (Mangefera indica L.) in Sierra Leone, causing extensive direct and indirect damage. A survey was c...Tephritid fruit flies are considered one of the world’s most notorious pests of horticultural crops, including mango (Mangefera indica L.) in Sierra Leone, causing extensive direct and indirect damage. A survey was conducted among 60 mango farmers in 7 districts in Sierra Leone between June and August, 2022, to assess their perceptions regarding fruit fly pest status and the current management options adopted for the control of this pest. Semi-structured questions designed in an open and closed-ended fashion were used for the study. The majority (83%) of the farmers were already aware of the fruit fly problem in the country with 62% perceiving it to be very severe. The majority (60%) of farmers, however, demonstrated poor knowledge of identifying fruit fly species, especially Bactrocera dorsalis, Ceratitis capitata, and Ceratitis cosyra. Farmers were more conversant about the direct damage symptoms to host fruits and the economic impact of fruit flies. A total of 32% of growers took no action to control fruit flies on their farms. Sixty-nine percent (69%) of the farmers adopted cultural control measures, like practicing prompt harvesting, collection and disposal of infested fruits, and weeding to maintain better sanitary conditions on their farms. Recommended fruit fly management strategies such as the use of botanicals and resistant varieties were either unknown or inaccessible to growers. A total of 52% applied chemicals that were not recommended for the control of fruit flies without considering their environmental and health risks. It is important to train fruit growers to improve their capabilities for fruit fly management through extension agents that are appropriate for helping them acquire basic knowledge of fruit fly pests and their management.展开更多
Nudiviruses represent a diverse group of arthropod specific, rod-shaped and dsDNA viruses. Due to similarities in pathology and morphology to members of the family Baculoviridae, they have been previously classified a...Nudiviruses represent a diverse group of arthropod specific, rod-shaped and dsDNA viruses. Due to similarities in pathology and morphology to members of the family Baculoviridae, they have been previously classified as the so-called “non-occluded” baculoviruses. However, presently they are taxonomically orphaned and are not assigned to any virus family because of the lack of genetic relatedness to Baculoviridae,. Here, we report on recent progress in the genomic analysis of Heliothis zea nudivirus 1 (HzNV-1), Oryctes rhinoceros nudivirus (OrNV), Gryllus bimaculatus nudivirus (GbNV) and Heliotis zea nudivirus 2 (HzNV-2). Gene content comparison and phylogenetic analyses indicated that the viruses share 15 core genes with baculoviruses and form a monophyletic sister group to them. Consequences of the genetic relationship are discussed for the classification of nudiviruses.展开更多
Red rice is one of the major troublesome and difficult weeds to control in rice production regions. The introduction of the Clearfield® technology allowed producers to control red rice using rice genotypes tol...Red rice is one of the major troublesome and difficult weeds to control in rice production regions. The introduction of the Clearfield® technology allowed producers to control red rice using rice genotypes tolerant to the imidazolinone herbicides. However, because the consecutive use of this technology red rice biotypes have evolved resistance to imidazolinone herbicides, the rice-soybean rotation has been an alternative used by producers to control this weed. This system allows the use of herbicides with different modes of action to control red rice, such as S-metolachlor. Thus, greenhouse and field experiments were carried out during the 2011 to 2012 and 2012 to 2013 growing seasons to evaluate: 1) sensitivity of imidazolinone-resistant red rice to S-metolachlor;2) red rice control and soybean tolerance in response to associations of S-metolachlor and glyphosate. In greenhouse, S-metolachlor effectively controlled both susceptible and imidazolinone-resistant red rice in preemergence. In field, preemergence applications of S-metolachlor provided greater red rice control in comparison to S-metolachlor alone in early postemergence. The association of S-metolachlor with glyphosate did not improve red rice control in preemergence application. However, association of S-metolachlor with glyphosate significantly improved red rice control in early postemergence applications. S-metolachlor injury to soybean increased with early postemergence applications. These results indicate that S-metolachlor effectively control imidazolinone-resistant red rice in rice-soybean rotation.展开更多
The use of artificial diets to mass reared insect stock under laboratory conditions, promotes knowledge about the biology, behavior, and nutritional requirements of insects;with such information being fundamental for ...The use of artificial diets to mass reared insect stock under laboratory conditions, promotes knowledge about the biology, behavior, and nutritional requirements of insects;with such information being fundamental for the formulation of efficient integrated pest management programs (IPM) strategies. However, the artificial diets used for rearing Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in the laboratory in this study, do not contain wheat germ, used for routine laboratory rearing. The aim of this study was to compare food preference and consumption by S. frugiperda larvae, as well as evaluate insect developmental parameters in the standard diet and the bean-based diets under laboratory conditions. Four artificial diets were used: a standard diet based on broad beans (Phaseolus vulgaris L.) used to rear S. frugiperda (D1), a diet with the substitution of two types of beans, cowpea (Vigna unguiculata L.) (D2) and pigeon pea (Cajanus cajan L) (D3);and a diet of fresh corn leaves (D4), the host plant of the pest species. Using a multiple-choice test, we observed that the larvae preferred diets D4 followed by D1. The relative consumption rate (RCR), relative growth rate (RGR), relative metabolic rate (RMR), approximate digestibility (AD), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and the metabolic cost (CM) for S. frugiperda fifth instar larvae varied among diets. The diet D4 resulted in better ingestion, digestion, assimilation, and conversion of food, but with a metabolic cost to assimilate the food. The different bean varieties present in the diet influenced larval length, larval periods, larval survival, pupal periods, sex ratio, pupal weight, and pupal survival;but fecundity and longevity of adults were not affected. The different bean-based diets did positively influence population growth, with the most outstanding being D4. From the results of this study, the most adequate diet for rearing S. frugiperda in the laboratory is D4.展开更多
文摘Tephritid fruit flies are considered one of the world’s most notorious pests of horticultural crops, including mango (Mangefera indica L.) in Sierra Leone, causing extensive direct and indirect damage. A survey was conducted among 60 mango farmers in 7 districts in Sierra Leone between June and August, 2022, to assess their perceptions regarding fruit fly pest status and the current management options adopted for the control of this pest. Semi-structured questions designed in an open and closed-ended fashion were used for the study. The majority (83%) of the farmers were already aware of the fruit fly problem in the country with 62% perceiving it to be very severe. The majority (60%) of farmers, however, demonstrated poor knowledge of identifying fruit fly species, especially Bactrocera dorsalis, Ceratitis capitata, and Ceratitis cosyra. Farmers were more conversant about the direct damage symptoms to host fruits and the economic impact of fruit flies. A total of 32% of growers took no action to control fruit flies on their farms. Sixty-nine percent (69%) of the farmers adopted cultural control measures, like practicing prompt harvesting, collection and disposal of infested fruits, and weeding to maintain better sanitary conditions on their farms. Recommended fruit fly management strategies such as the use of botanicals and resistant varieties were either unknown or inaccessible to growers. A total of 52% applied chemicals that were not recommended for the control of fruit flies without considering their environmental and health risks. It is important to train fruit growers to improve their capabilities for fruit fly management through extension agents that are appropriate for helping them acquire basic knowledge of fruit fly pests and their management.
基金Foundation item: the Deutsche Forschungsgemeinschaft (DFG) to J.A.J (Je245-7).
文摘Nudiviruses represent a diverse group of arthropod specific, rod-shaped and dsDNA viruses. Due to similarities in pathology and morphology to members of the family Baculoviridae, they have been previously classified as the so-called “non-occluded” baculoviruses. However, presently they are taxonomically orphaned and are not assigned to any virus family because of the lack of genetic relatedness to Baculoviridae,. Here, we report on recent progress in the genomic analysis of Heliothis zea nudivirus 1 (HzNV-1), Oryctes rhinoceros nudivirus (OrNV), Gryllus bimaculatus nudivirus (GbNV) and Heliotis zea nudivirus 2 (HzNV-2). Gene content comparison and phylogenetic analyses indicated that the viruses share 15 core genes with baculoviruses and form a monophyletic sister group to them. Consequences of the genetic relationship are discussed for the classification of nudiviruses.
文摘Red rice is one of the major troublesome and difficult weeds to control in rice production regions. The introduction of the Clearfield® technology allowed producers to control red rice using rice genotypes tolerant to the imidazolinone herbicides. However, because the consecutive use of this technology red rice biotypes have evolved resistance to imidazolinone herbicides, the rice-soybean rotation has been an alternative used by producers to control this weed. This system allows the use of herbicides with different modes of action to control red rice, such as S-metolachlor. Thus, greenhouse and field experiments were carried out during the 2011 to 2012 and 2012 to 2013 growing seasons to evaluate: 1) sensitivity of imidazolinone-resistant red rice to S-metolachlor;2) red rice control and soybean tolerance in response to associations of S-metolachlor and glyphosate. In greenhouse, S-metolachlor effectively controlled both susceptible and imidazolinone-resistant red rice in preemergence. In field, preemergence applications of S-metolachlor provided greater red rice control in comparison to S-metolachlor alone in early postemergence. The association of S-metolachlor with glyphosate did not improve red rice control in preemergence application. However, association of S-metolachlor with glyphosate significantly improved red rice control in early postemergence applications. S-metolachlor injury to soybean increased with early postemergence applications. These results indicate that S-metolachlor effectively control imidazolinone-resistant red rice in rice-soybean rotation.
文摘The use of artificial diets to mass reared insect stock under laboratory conditions, promotes knowledge about the biology, behavior, and nutritional requirements of insects;with such information being fundamental for the formulation of efficient integrated pest management programs (IPM) strategies. However, the artificial diets used for rearing Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in the laboratory in this study, do not contain wheat germ, used for routine laboratory rearing. The aim of this study was to compare food preference and consumption by S. frugiperda larvae, as well as evaluate insect developmental parameters in the standard diet and the bean-based diets under laboratory conditions. Four artificial diets were used: a standard diet based on broad beans (Phaseolus vulgaris L.) used to rear S. frugiperda (D1), a diet with the substitution of two types of beans, cowpea (Vigna unguiculata L.) (D2) and pigeon pea (Cajanus cajan L) (D3);and a diet of fresh corn leaves (D4), the host plant of the pest species. Using a multiple-choice test, we observed that the larvae preferred diets D4 followed by D1. The relative consumption rate (RCR), relative growth rate (RGR), relative metabolic rate (RMR), approximate digestibility (AD), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and the metabolic cost (CM) for S. frugiperda fifth instar larvae varied among diets. The diet D4 resulted in better ingestion, digestion, assimilation, and conversion of food, but with a metabolic cost to assimilate the food. The different bean varieties present in the diet influenced larval length, larval periods, larval survival, pupal periods, sex ratio, pupal weight, and pupal survival;but fecundity and longevity of adults were not affected. The different bean-based diets did positively influence population growth, with the most outstanding being D4. From the results of this study, the most adequate diet for rearing S. frugiperda in the laboratory is D4.
