Assessment of quality of biological control agents is an important step for the success of any biocontrol program.Experiments were carried out to select candidate Trichogramma species for use in biological control of ...Assessment of quality of biological control agents is an important step for the success of any biocontrol program.Experiments were carried out to select candidate Trichogramma species for use in biological control of the olive moth Prays oleae Bern(Lepidoptera,Yponomeutidae).Thirteen local strains were preselected on the basis of the geographical origin and the availability from mass production of the rearing host Ephestia kuehniella ZELL.(Lepidoptera,Pyralidae) under laboratory conditions.Selection tests were focusing on acceptance and preference for P.oleae eggs.In the acceptance test,a single parasitoid female was offered P.oleae eggs on "tricho-card" for 6 hours at 25°C,70% HR and L16:D9 and assessed for parasitism after 6 days.The preference was determined by offering the choice and observing contacts with eggs of the target pest P.oleae and eggs of the host E.kuehniella.Parasitism was therefore assessed 6 days after the experiment under similar laboratory conditions.In host acceptance test,most eggs of P.oleae were parasited by strains belonging to the species T.oleae,T.bourarachae and T.cacoeciae.These strains also showed a high number of contacts with olive moth eggs in preference tests.However,a small number of T.bourarachae observed ovipositions resulted in successful parasitism.Therefore,T.oleae and T.cacoeciae were selected as candidates for further experiments.展开更多
The Bactrocera oleae Rossi fly is the most important olive pest. It is of major economic importance in the olive production area of Essaouira, where weather conditions are optimal for the conduct of the various stages...The Bactrocera oleae Rossi fly is the most important olive pest. It is of major economic importance in the olive production area of Essaouira, where weather conditions are optimal for the conduct of the various stages of its life cycle. The lack of phytosanitary treatments worsens this situation. The development of the larval stages and different generations are related to the phenological stages of the olive and are controlled by changes in habitat conditions. Trapping of adult males by Deltas traps baited with sex pheromone, at the four study sites, has identified some characteristics of the evolution of the adult populations’ flight dynamics. Our main results show a decreasing gradient of early emergences of different stages from the coast to the continental areas as well as the absence of the summer generation at the inner station. Soil analysis in the two stations showed that the hypogenous pupae wintering in the soil survive until June. Knowledge of the factors involved in the bio-ecology of the olive fly and the phenology of the host allows the elaboration of monitoring/ warning calendars, and phytosanitary measures in order to establish an IPM program adapted to the requirements of olive orchards in the region.展开更多
The olive fruit fly Bactrocera oleae is a major olive pest in Algeriaand other Mediterranean countries. Its attacks, in some cases, seriously compromised production. Bacillus thuringiensis is a spore-forming soil bact...The olive fruit fly Bactrocera oleae is a major olive pest in Algeriaand other Mediterranean countries. Its attacks, in some cases, seriously compromised production. Bacillus thuringiensis is a spore-forming soil bacterium which produces a protein crystal toxic to some insects. The objective of this study was to search for isolates toxic to larvae and adults of B. oleae. Four doses test were performed on neonate larvae, second instar larvae and third instar larvae. Seven Bt strains examined, showed highest toxicity levels against adults. 86% mortality was observed against neonate larvae after 7 days of application by Bt toxin isolate. The mortality of the second instar larvae was 65% mortality at dose of 108 UFC/mL. The third instar larvae was very susceptible to Bt strain with 70% of mortality. This study demonstrated that some local Algerian B. thuringiensis isolates exhibit toxic potential that could be used to control B. oleae.展开更多
Bactrocera oleae is the most economically damaging insect of olive in the Mediterranean. As a reliable alternative to synthetic chemical insecticides, botanical pesticides from plant extracts are also considered natur...Bactrocera oleae is the most economically damaging insect of olive in the Mediterranean. As a reliable alternative to synthetic chemical insecticides, botanical pesticides from plant extracts are also considered natural control methods safe for the environment and human health. In practical applications up to date, studies demonstrating toxically effects of biological control agents on the insect have been carried out in organic farming systems based on some industrial microbial formulations. But much less attention has been given to botanical insecticides against B. oleae. Thus, a certified botanical insecticide issue from various plants and approved per Indian and International organic standards was tested against larvae and pupae of the olive pest Bactrocera oleae in the east of Tunisia under laboratory conditions. The experiments were conducted with 3 normal treatments and 1 control. Two techniques were used for larvae and pupae: direct contact using concentration from 0.5;0.750;1 and 1.5 mg/l and fumigation treatment using 2 mg/l conducted in rectangular boxes (25°C - 27°C, 75% - 85% RH and 14:10 LD photo period). For larval stages, LC50 and LC90 values for Ultra-Act were 0.45 and 1.22 mg/L in direct contact and 1.5 - 2 mg/l with fumigation, respectively. For pupal stage, the ID25 and ID50 values were estimated to be 0.71 mg and 1.26 mg respectively corresponding to the inhibition of emergence of 25% and 50% of B. oleae adults from pupa. Our results indicate that sprayed Ultra-Act product has the potential to control the three olive fly instar larvae. Pupal emergency was decreased significantly with fumigation treatment. In conclusion, Ultra-Act is a promising botanical insecticide against B. oleae that could be used as a successful alternative for chemicals in integrated control methods of this pest in Tunisia.展开更多
The olive fruit fly(Bactrocera oleae)is a significant pest threatening olive production worldwide.Bactrocera oleae relies on symbiotic bacteria for nutrition,development,and adaptation to its environment.Among these,C...The olive fruit fly(Bactrocera oleae)is a significant pest threatening olive production worldwide.Bactrocera oleae relies on symbiotic bacteria for nutrition,development,and adaptation to its environment.Among these,Candidatus Erwinia dacicola is the most dominant symbiont and plays a key role in the fly's physiology and ecological adaptation.Understanding the dynamics between B.oleae,Ca.E.dacicola,and other components of the B.oleae microbiome is essential for developing effective targeted area-wide pest management strategies.This study aims to leverage full 16S rRNA gene sequencing to enhance the characterization of microbiome diversity in wild B.oleae populations from different regions in Morocco:Ouezzane,Rabat,Tanger,Errachidia,and Beni-Mellal.The results revealed distinct microbiome compositions influenced by geographic locations,with Candidatus Erwinia dacicola as the dominant symbiont,followed by Erwinia persicina as a secondary contributor.Other bacterial taxa,including Asaia bogorensis,were also identified,highlighting the functional diversity within the olive fly microbiome.These findings provide insights into the microbial ecology of B.oleae,contributing to the development and enhancement of sustainable pest control strategies.展开更多
Inter-simple sequence repeat（ISSR） molecular markers were applied to analyze the genetic diversity and clustering of 48 introduced and bred cultivars of Olea euyopaea L. Totally 106 DNA bands were amplified by 11 sc...Inter-simple sequence repeat（ISSR） molecular markers were applied to analyze the genetic diversity and clustering of 48 introduced and bred cultivars of Olea euyopaea L. Totally 106 DNA bands were amplified by 11 screened primers, including 99 polymorphic bands; the percentage of polymorphic loci was 93.40%, indicating a rich genetic diversity in Olea euyopaea L. germplasm resources. Based on Nei＇s genetic distances between various cultivars, a dendrogram of 48 cultivars of Olea euyopaea L. was constructed using unweighted pair-group（UPMGA）method,which showed that 48 cultivars were clustered into four main categories; 84.6% of native cultivars were clustered into two categories; most of introduced cultivars were clustered based on their sources and main usages but not on their geographic origins. This study will provide references for the utilization and further genetic improvement of Olea euyopaea L. germplasm resources.展开更多
Olive fruits are seriously deteriorated by pre and postharvest damage due to the attack of insects, such as Bactrocera olaea, which strongly alters the quality of olives. Defence response in olive fruits injured both ...Olive fruits are seriously deteriorated by pre and postharvest damage due to the attack of insects, such as Bactrocera olaea, which strongly alters the quality of olives. Defence response in olive fruits injured both by pathogens and by mechanical damages has been associated with the enzyme β-glucosidase, which specifically hydrolyses oleuropein, producing highly reactive aldehyde molecules. In situ detection of ^-glucosidase activity in olive fruit tissues following injury, which simulates Bactrocera oleae punctures, is reported. The assay was performed in two cultivars showing different degrees of susceptibilities to fly infestation. In both cultivars, the histochemical assay for β-glucosidase showed that within 20 min after the injury, a strong ^-glucosidase activity could be observed in the damaged tissues. Thereafter a progressive enzyme inactivation occurred starting from tissues around the boundary of the injury with decrease of the enzyme activity and stopped after 3 h. Whereas the mass of active cells reached a distance of （300±50） μm from the edge of the injury. Biochemical analyses showed that in extracts of the injured fruit, β-glucosidase activity rapidly increased within 20 min from injury, thereafter decreasing and reaching values comparable with those in intact fruits. Following puncture, the oleuropein contents did not change significantly in the high susceptibility cultivar, whereas it rapidly decreased in the cultivar showing low susceptibility. The results strongly suggest that olive fruits susceptible towards fly infestation could be related to the ability of the oleuropein-degrading-β-glucosidase to produce the highly reactive molecules in the damaged tissues. As a consequence of puncture, high level of peroxidase activity was detected. This feature also suggested that this enzyme could play a key role in the defence response against insect injuries.展开更多
基金INCODEV (TRIPHELIO) (UE/ 2002-2005) :Sustainable Control of Lepidopterous Pests in Olive Groves - Integration of Egg Parasitoids and Pheromones
文摘Assessment of quality of biological control agents is an important step for the success of any biocontrol program.Experiments were carried out to select candidate Trichogramma species for use in biological control of the olive moth Prays oleae Bern(Lepidoptera,Yponomeutidae).Thirteen local strains were preselected on the basis of the geographical origin and the availability from mass production of the rearing host Ephestia kuehniella ZELL.(Lepidoptera,Pyralidae) under laboratory conditions.Selection tests were focusing on acceptance and preference for P.oleae eggs.In the acceptance test,a single parasitoid female was offered P.oleae eggs on "tricho-card" for 6 hours at 25°C,70% HR and L16:D9 and assessed for parasitism after 6 days.The preference was determined by offering the choice and observing contacts with eggs of the target pest P.oleae and eggs of the host E.kuehniella.Parasitism was therefore assessed 6 days after the experiment under similar laboratory conditions.In host acceptance test,most eggs of P.oleae were parasited by strains belonging to the species T.oleae,T.bourarachae and T.cacoeciae.These strains also showed a high number of contacts with olive moth eggs in preference tests.However,a small number of T.bourarachae observed ovipositions resulted in successful parasitism.Therefore,T.oleae and T.cacoeciae were selected as candidates for further experiments.
文摘The Bactrocera oleae Rossi fly is the most important olive pest. It is of major economic importance in the olive production area of Essaouira, where weather conditions are optimal for the conduct of the various stages of its life cycle. The lack of phytosanitary treatments worsens this situation. The development of the larval stages and different generations are related to the phenological stages of the olive and are controlled by changes in habitat conditions. Trapping of adult males by Deltas traps baited with sex pheromone, at the four study sites, has identified some characteristics of the evolution of the adult populations’ flight dynamics. Our main results show a decreasing gradient of early emergences of different stages from the coast to the continental areas as well as the absence of the summer generation at the inner station. Soil analysis in the two stations showed that the hypogenous pupae wintering in the soil survive until June. Knowledge of the factors involved in the bio-ecology of the olive fly and the phenology of the host allows the elaboration of monitoring/ warning calendars, and phytosanitary measures in order to establish an IPM program adapted to the requirements of olive orchards in the region.
文摘The olive fruit fly Bactrocera oleae is a major olive pest in Algeriaand other Mediterranean countries. Its attacks, in some cases, seriously compromised production. Bacillus thuringiensis is a spore-forming soil bacterium which produces a protein crystal toxic to some insects. The objective of this study was to search for isolates toxic to larvae and adults of B. oleae. Four doses test were performed on neonate larvae, second instar larvae and third instar larvae. Seven Bt strains examined, showed highest toxicity levels against adults. 86% mortality was observed against neonate larvae after 7 days of application by Bt toxin isolate. The mortality of the second instar larvae was 65% mortality at dose of 108 UFC/mL. The third instar larvae was very susceptible to Bt strain with 70% of mortality. This study demonstrated that some local Algerian B. thuringiensis isolates exhibit toxic potential that could be used to control B. oleae.
文摘Bactrocera oleae is the most economically damaging insect of olive in the Mediterranean. As a reliable alternative to synthetic chemical insecticides, botanical pesticides from plant extracts are also considered natural control methods safe for the environment and human health. In practical applications up to date, studies demonstrating toxically effects of biological control agents on the insect have been carried out in organic farming systems based on some industrial microbial formulations. But much less attention has been given to botanical insecticides against B. oleae. Thus, a certified botanical insecticide issue from various plants and approved per Indian and International organic standards was tested against larvae and pupae of the olive pest Bactrocera oleae in the east of Tunisia under laboratory conditions. The experiments were conducted with 3 normal treatments and 1 control. Two techniques were used for larvae and pupae: direct contact using concentration from 0.5;0.750;1 and 1.5 mg/l and fumigation treatment using 2 mg/l conducted in rectangular boxes (25°C - 27°C, 75% - 85% RH and 14:10 LD photo period). For larval stages, LC50 and LC90 values for Ultra-Act were 0.45 and 1.22 mg/L in direct contact and 1.5 - 2 mg/l with fumigation, respectively. For pupal stage, the ID25 and ID50 values were estimated to be 0.71 mg and 1.26 mg respectively corresponding to the inhibition of emergence of 25% and 50% of B. oleae adults from pupa. Our results indicate that sprayed Ultra-Act product has the potential to control the three olive fly instar larvae. Pupal emergency was decreased significantly with fumigation treatment. In conclusion, Ultra-Act is a promising botanical insecticide against B. oleae that could be used as a successful alternative for chemicals in integrated control methods of this pest in Tunisia.
基金Particularly the FAO/IAEA Coordinated Research Project"Colony management of insects for sterile insect technique application"allowed to exchange valuable information related to the study of key symbiont species associated to massproduced insectsFunding was provided by FAO/IAEA contract 22662funded through the ERASMUS+International mobility program KA107.
文摘The olive fruit fly(Bactrocera oleae)is a significant pest threatening olive production worldwide.Bactrocera oleae relies on symbiotic bacteria for nutrition,development,and adaptation to its environment.Among these,Candidatus Erwinia dacicola is the most dominant symbiont and plays a key role in the fly's physiology and ecological adaptation.Understanding the dynamics between B.oleae,Ca.E.dacicola,and other components of the B.oleae microbiome is essential for developing effective targeted area-wide pest management strategies.This study aims to leverage full 16S rRNA gene sequencing to enhance the characterization of microbiome diversity in wild B.oleae populations from different regions in Morocco:Ouezzane,Rabat,Tanger,Errachidia,and Beni-Mellal.The results revealed distinct microbiome compositions influenced by geographic locations,with Candidatus Erwinia dacicola as the dominant symbiont,followed by Erwinia persicina as a secondary contributor.Other bacterial taxa,including Asaia bogorensis,were also identified,highlighting the functional diversity within the olive fly microbiome.These findings provide insights into the microbial ecology of B.oleae,contributing to the development and enhancement of sustainable pest control strategies.
基金Supported by Key Project of New Product Development in Yunnan Province(2009BB006)~~
文摘Inter-simple sequence repeat（ISSR） molecular markers were applied to analyze the genetic diversity and clustering of 48 introduced and bred cultivars of Olea euyopaea L. Totally 106 DNA bands were amplified by 11 screened primers, including 99 polymorphic bands; the percentage of polymorphic loci was 93.40%, indicating a rich genetic diversity in Olea euyopaea L. germplasm resources. Based on Nei＇s genetic distances between various cultivars, a dendrogram of 48 cultivars of Olea euyopaea L. was constructed using unweighted pair-group（UPMGA）method,which showed that 48 cultivars were clustered into four main categories; 84.6% of native cultivars were clustered into two categories; most of introduced cultivars were clustered based on their sources and main usages but not on their geographic origins. This study will provide references for the utilization and further genetic improvement of Olea euyopaea L. germplasm resources.
文摘Olive fruits are seriously deteriorated by pre and postharvest damage due to the attack of insects, such as Bactrocera olaea, which strongly alters the quality of olives. Defence response in olive fruits injured both by pathogens and by mechanical damages has been associated with the enzyme β-glucosidase, which specifically hydrolyses oleuropein, producing highly reactive aldehyde molecules. In situ detection of ^-glucosidase activity in olive fruit tissues following injury, which simulates Bactrocera oleae punctures, is reported. The assay was performed in two cultivars showing different degrees of susceptibilities to fly infestation. In both cultivars, the histochemical assay for β-glucosidase showed that within 20 min after the injury, a strong ^-glucosidase activity could be observed in the damaged tissues. Thereafter a progressive enzyme inactivation occurred starting from tissues around the boundary of the injury with decrease of the enzyme activity and stopped after 3 h. Whereas the mass of active cells reached a distance of （300±50） μm from the edge of the injury. Biochemical analyses showed that in extracts of the injured fruit, β-glucosidase activity rapidly increased within 20 min from injury, thereafter decreasing and reaching values comparable with those in intact fruits. Following puncture, the oleuropein contents did not change significantly in the high susceptibility cultivar, whereas it rapidly decreased in the cultivar showing low susceptibility. The results strongly suggest that olive fruits susceptible towards fly infestation could be related to the ability of the oleuropein-degrading-β-glucosidase to produce the highly reactive molecules in the damaged tissues. As a consequence of puncture, high level of peroxidase activity was detected. This feature also suggested that this enzyme could play a key role in the defence response against insect injuries.
