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S A Hassan - One of the best experts on this subject based on the ideXlab platform.
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Temperature and strain effects on reproduction and survival of Trichogramma Oleae and Trichogramma cacoeciae (Hymenoptera: Trichogrammatidae)
Biocontrol Science and Technology, 2011Co-Authors: Ines Ksentini, Mohieddine Ksantini, Annette Herz, Taieb Jardak, S A HassanAbstract:To assess differences in temperature sensitivity during development, life tables for two lines derived from the species Trichogramma Oleae Voegel+® and Pointel and a strain of Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae) were elaborated at 15, 20, 25, 30, 35, 36, and 37-¦C in the laboratory. Eggs of Ephestia kuehniella Zeller together with a fresh drop of honey were supplied every 2 days until the death of the test females, and the removed host egg batches were placed in the equivalent rearing cabinet. The line ?2F? of T. Oleae was found to be the most efficient at any range of temperatures except at 20 and 37-¦C, in comparison to the other tested strains. For all species, no progeny emerged from eggs incubated at 36-¦C and none of the parasitized eggs turned black at 37-¦C. The better performance at a broader range of temperatures by T. Oleae (line 2 F) might be caused by a shorter history in artificial rearing in comparison to the other strains. Fewer generations at laboratory conditions and frequent multiplication on eggs of its natural host (the olive moth Prays Oleae) may have prevented a deterioration in the rearing population of this strain, maintaining its genetic diversity at a higher scale. Applying varying temperature regimes on the rearing stock at regular intervals during the mass production process may help to maintain the essential quality of the biological control agents for field performance at higher temperaturesAbstract To assess differences in temperature sensitivity during development, life tables for two lines derived from the species Trichogramma Oleae Voegel+® and Pointel and a strain of Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae) were elaborated at 15, 20, 25, 30, 35, 36, and 37-¦C in the laboratory. Eggs of Ephestia kuehniella Zeller together with a fresh drop of honey were supplied every 2 days until the death of the test females, and the removed host egg batches were placed in the equivalent rearing cabinet. The line ?2F? of T. Oleae was found to be the most efficient at any range of temperatures except at 20 and 37-¦C, in comparison to the other tested strains. For all species, no progeny emerged from eggs incubated at 36-¦C and none of the parasitized eggs turned black at 37-¦C. The better performance at a broader range of temperatures by T. Oleae (line 2 F) might be caused by a shorter history in artificial rearing in comparison to the other strains. Fewer generations at laboratory conditions and frequent multiplication on eggs of its natural host (the olive moth Prays Oleae) may have prevented a deterioration in the rearing population of this strain, maintaining its genetic diversity at a higher scale. Applying varying temperature regimes on the rearing stock at regular intervals during the mass production process may help to maintain the essential quality of the biological control agents for field performance at higher temperatures
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field efficiency of indigenous egg parasitoids hymenoptera trichogrammatidae to control the olive moth Prays Oleae lepidoptera yponomeutidae and the jasmine moth palpita unionalis lepidoptera pyralidae in an olive plantation in egypt
Biological Control, 2007Co-Authors: E M Hegazi, Annette Herz, Wedad E Khafagi, E Agamy, Ahmed Zaitun, S A Hassan, Somaia Elsaid, Gehan Abd M Elaziz, Sania Showeil, N KhamisAbstract:Abstract The olive moth, Prays Oleae (Bern.), and the jasmine moth, Palpita unionalis (Hubner), are serious pests in modern olive plantations in Egypt, causing significant yield loss by fruit fall as well as by damage on leaves, flowers and fruits. The egg parasitoid species Trichogramma bourarachae Pintureau and Babault, T. cordubensis Vargas and Cabello, T. euproctidis Girault, all collected in olive groves in Egypt, as well as the commercially available T. evanescens Westwood, originating from sugarcane fields in Egypt, were released in several applications in an intensively managed olive plantation for biological control of these pests. Impact of releases was monitored by recording egg parasitism, pest larval densities, fruit damage and fruit yield. Indigenous Trichogramma species accomplished higher egg parasitism (up to 91%) than the commercial strain. Larval densities of target pests were significantly reduced up to 83% on Trichogramma release trees in comparison to control trees. Fruit damage ranged below 10% infested fruits and fruit yield was significantly increased on trees where indigenous wasps had been applied. The results suggested that releases of the indigenous T. bourarachae, T. cordubensis and T. euproctidis could improve control of lepidopterous pests on olive. The species T. bourarachae was most efficient in dispersal and foraging. Not native to this particular olive plantation before, it could sustainably be established after the releases in 2004. The outcome of this field experiment is encouraging for an efficient use of local Trichogramma spp. and represents a starting point for future optimization of the method.
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Are indigenous strains of Trichogramma sp. (Hym., Trichogrammatidae) better candidates for biological control of lepidopterous pests of the olive tree?
Biocontrol Science and Technology, 2006Co-Authors: Annette Herz, S A HassanAbstract:Abstract Strains of the egg parasitoid, Trichogramma, indigenous in olive groves in the Mediterranean region (T. bourarachae Pintureau & Babault, T. cacoeciae Marchal, T. cordubensis Vargas & Cabello, T. euproctidis Girault, T. nerudai Pintureau & Gerding, T. Oleae Voegele & Pointel) as well as commercially available strains (T. brassicae Bezdenko, T. cacoeciae, T. evanescens Westwood), were assessed in laboratory and semi-field experiments for their attributes as biological control agents for use against lepidopterous olive pests like the olive moth (Prays Oleae Bern.) and the jasmine moth (Palpita unionalis Hubn.). In a choice test, an Egyptian strain of T. cordubensis parasitized significantly more olive and jasmine moth eggs than those of the rearing host Sitotroga cerealella Olivier. This strain was also most efficient in finding eggs of the target pests on olive foliage and on potted olive trees. Survival and fecundity of a Tunisian strain of T. bourarachae was not affected when exposed to hot (35°C...
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Towards sustainable control of Lepidopterous pests in olive cultivation
Gesunde Pflanzen, 2005Co-Authors: Annette Herz, Mohieddine Ksantini, Wedad E Khafagi, E Agamy, Taieb Jardak, S A Hassan, F. N. Nasr, Esmat Hegazi, Ali A. Youssef, Basilis E MazomenosAbstract:Traditionelle, extensiv bearbeitete Olivenhaine, aber auch moderne Intensiv-Plantagen mit kunstlicher Bewasserung und hohem Einsatz von Dungern bzw. chemischen Pflanzenschutzmitteln kennzeichnen die derzeitigen verschiedenen Anbauformen der Olive im Mittelmeerraum. Schadlepidopteren wie die Olivenmotte (Prays Oleae, Lep.: Yponomeutidae) und die Jasminmotte (Palpita unionalis, Lep.: Pyralidae) werden durch regelmassigen Insektizideinsatz bekampft. Das von der EU geforderte internationale Forschungsprojekt TRIPHELIO zielte auf die Entwicklung insektizidfreier Alternativmethoden durch (1) die Optimierung der pheromongestutzten Uberwachung und Verwirrtechnik, (2) der Anwendung von Habitatmanagement-Strategien zur Forderung naturlicher Gegenspieler, und (3) dem Einsatz von Trichogramma-Schlupfwespen. Zusatzlich wurden Module fur eine optimale Anwendung biotechnischer und biologischer Methoden bezuglich der Phanologie der Schadinsekten und moglicher Nebenwirkungen von Pestiziden erarbeitet. Die intensive Kooperation zwischen Wissenschaftlern und Praktikern aus mehreren Landern Europas und Nordafrikas erlaubte den Entwurf moglicher Losungsansatze fur verschiedene Anbaubedingungen und klimatische Regionen des Mittelmeerraumes. Die wichtigsten Ergebnisse und Ausblicke fur eine zukunftige praktische Umsetzung werden in dieser Veroffentlichung beschrieben.
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ants as predators of the egg parasitoid trichogramma cacoeciae hymenoptera trichogrammatidae applied for biological control of the olive moth Prays Oleae lepidoptera plutellidae in portugal
Biocontrol Science and Technology, 2004Co-Authors: Jose Alberto Pereira, Albino Bento, J E Cabanas, L Torres, Annette Herz, S A HassanAbstract:The detrimental effect of predators on Trichogramma cacoeciae March. releases to control the olive moth, Prays Oleae Bern., in the Tras-os-Montes region (Northeast of Portugal), was evaluated during three releases against the flower generation of the pest in 2002. At 1 and 3 h and at 1, 3, 7 and 14 days after each release, 30 Trichogramma releasing cards were examined in the field and predators were collected and identified. Furthermore, at 1, 3, 7 and 14 days after each release, the percentage of egg predation on the cards was also determined. Formicidae were the most abundant group of predators at 99.1% of the total individuals collected. Ten species were identified, Camponotus aethiops, C. lateralis, C. piceus, C. truncatus, Crematogaster auberti, C. scutellaris, Lasius niger, Leptotorax angustulus, Plagiolephis pygmaea and Tapinoma nigerrimum. T. nigerrimum was the most abundant species, both in total numbers as well as in the number of occupied cards. One day after release, the percentage of predation was 24.0% in the first release, 59.4% in the second and 38.0% in the third. Three days after release, the percentage of predation varied from 60.2 to 83.4% during the three release events. Seven days after release, the percentage of predation increased to 97.8% of the total eggs on cards.
Samir Jaoua - One of the best experts on this subject based on the ideXlab platform.
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comparative study of bacillus thuringiensis cry1ia and cry1aa delta endotoxins activation process and toxicity against Prays Oleae
Journal of Invertebrate Pathology, 2010Co-Authors: Mariam Dammak, Souad Rouis, Slim Tounsi, Samir JaouaAbstract:Abstract Cry1Ia and Cry1Aa proteins exhibited toxicities against Prays Oleae with LC 50 of 189 and 116 ng/cm 2 , respectively. The ability to process Cry1Ia11 protoxin by trypsin, chymotrypsin and P. Oleae larvae proteases was studied and compared to that of Cry1Aa11. After solubilization under high alkaline condition (50 mM NaOH), Cry1Aa11 was converted into a major fragment of 65 kDa, whereas Cry1Ia11 protoxin was completely degraded by P. Oleae larvae proteases and trypsin and converted into a major fragment of 70 kDa by chymotrypsin. Using less proteases of P. Oleae juice, the degradation of Cry1Ia11 was attenuated. When the solubilization (in 50 mM Na 2 CO 3 pH 10.5 buffer) and activation were combined, Cry1Ia11 was converted into a proteolytic product of 70 kDa after 3 h of incubation with trypsin, chymotrypsin and P. Oleae juice. These results suggest that the in vivo solubilization of Cry1Ia11 was assured by larval proteases after a swelling of the corresponding inclusion due to the alkalinity of the larval midgut.
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Prays Oleae Midgut Putative Receptor of Bacillus thuringiensis Vegetative Insecticidal Protein Vip3LB Differs from that of Cry1Ac Toxin
Molecular Biotechnology, 2009Co-Authors: Lobna Abdelkefi-mesrati, Souad Rouis, Sameh Sellami, Samir JaouaAbstract:Vegetative insecticidal protein (Vip) is a class of insecticidal proteins produced by many Bacillus thuringiensis strains during their vegetative growth stage. The vip3LB gene of B. thuringiensis strain BUPM95, which encodes a protein active against the Lepidoptera olive tree pathogenic insect Prays Oleae , was cloned into pET-14b vector and overexpressed in Escherichia coli . The expressed Vip3LB protein, found in the E. coli cytoplasmic fraction, was purified and used to produce anti-Vip3LB antibodies. Using the midgut extract of P. Oleae , the purified Vip3LB bound to a 65-kDa protein, whereas Cry1Ac toxin bound to a 210-kDa midgut putative receptor. This result justifies the importance of the biological pest control agent Vip3LB that could be used as another alternative particularly in case of resistance to Cry toxins.
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Medium optimization for biomass production and morphology variance overcome of Photorhabdus temperata ssp. temperata strain K122
Process Biochemistry, 2008Co-Authors: Wafa Jallouli, Nabil Zouari, Walid Hammami, Samir JaouaAbstract:Abstract Photorhabdus temperata ssp. temperata strain K122 is an important pathogen of the olive moth, Prays Oleae. A new medium containing 5 g/l glucose, 10 g/l yeast extract and 1.07 g/l ammonium chloride is presented that optimizes the biomass production of strain K122. We also showed for the first time that P. temperata ssp. temperata strain K122 develops variants small colony (Vsm) polymorphism after prolonged incubation. Instability and reversion from one form to another are described. Since Vsm cells reduce pathogenicity against insect larvae, conditions to avoid their appearance were determined. Medium aeration and inoculum quality are demonstrated as key factors to reduce Vsm occurrence. Maintenance of initial glucose concentration during incubation not only doubled biomass production, but also contributed to complete overcome of Vsm appearance. Following oral application, it was shown that P. temperata ssp. temperata cells produced at such conditions continued to exhibit their toxicity against Ephestia kuehniella. This study might contribute to promote the large-scale use of P. temperata ssp. temperata as a bioinsecticide.
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evidence of oral toxicity of photorhabdus temperata strain k122 against Prays Oleae and its improvement by heterologous expression of bacillus thuringiensis cry1aa and cry1ia genes
Journal of Invertebrate Pathology, 2006Co-Authors: Slim Tounsi, Ammar Ebn Aoun, Mark Blight, Ahmed Rebai, Samir JaouaAbstract:Abstract Photorhabdus temperata strain K122 exhibited oral toxicity against Prays Oleae with an LC50 of 58.1 × 106 cells ml−1. Recombinant P. temperata strains expressing the cry1Aa and/or cry1Ia genes of Bacillus thuringiensis have been constructed. The two cry genes, encoding δ-endotoxins, were placed under the control of the lac promoter and IPTG dependent expression in P. temperata was demonstrated. The presence of the cry genes in K122 resulted in a clear improvement of oral toxicity. This improvement was of 6.2-, 6.6-, and 14.6-fold for the strains K122(pBCcry1Aa), K122(pBScry1Ia), and K122(pBCcry1Aa + pBScry1Ia), respectively. Furthermore, determination of the Synergistic Factor between Cry1Aa and Cry1Ia showed that they act synergistically. This work demonstrates that the heterologous expression of B. thuringiensis cry genes in P. temperata can be used to improve and broaden its host range for insect control.
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Cloning and nucleotide sequence of a novel cry1Aa-type gene from Bacillus thuringiensis subsp. kurstaki
Biotechnology Letters, 1999Co-Authors: Slim Tounsi, Nabil Zouari, Samir JaouaAbstract:A newly isolated strain of B. thuringiensis, BNS3, was identified as affiliated to the subsp. kurstaki and belonging to the serotype H3a, 3b, 3c. Insecticidal crystal proteins from BNS3 were active against lepidopteran larvae, particularly Prays Oleae, Ephestia kuehniella, Ostrinia nubilalis and Spodoptora exigua. The cloning and sequencing from BNS3 of a cry1Aa-type gene, called crybns3-1, revealed an open reading frame of 3531 bp, encoding a protein of 1176 amino acid residues. Both nucleotide and amino acid sequences similarity analysis revealed that crybns3-1 is a new cry1Aa-type gene, presenting several differences with the other cry1Aa-type genes.
Jose Alberto Pereira - One of the best experts on this subject based on the ideXlab platform.
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Do non-crop areas and landscape structure influence dispersal and population densities of male olive moth?
Bulletin of Entomological Research, 2020Co-Authors: Maria Villa, Sonia A P Santos, Susana Pascual, Jose Alberto PereiraAbstract:The permeability of the crop surroundings to pests and the landscape structure can influence pest dispersal between crop patches as well as its abundance within the crop. In this work, we analyzed the dispersal of the olive moth Prays Oleae (Bernard) throughout the olive grove surroundings and their abundance within the crop following three approaches: (i) pollen grains settled on bodies of olive moths collected in olive groves were identified and compared with flora occurring on the surrounding patches; (ii) the capability of P. Oleae males to penetrate non-crop patches was analyzed (iii) the effect of the landscape structure on the abundance of the three generations of the olive moth was studied. Pollen grains of scrubs and other trees occurring in the crop surroundings, such as Cistus sp., Quercus sp., Juniperus-type or Pinaceae were identified on P. Oleae bodies suggesting that P. Oleae penetrates into non-crop habitats. Additionally, woody and, to a lesser degree, herbaceous patches, did not constitute barriers for P. Oleae. Finally, more complex and heterogeneous patches presented lower numbers of captures of P. Oleae. These results give new insights into the movements of the olive moth in the olive grove surroundings and suggest that the management of non-crop areas could influence this pest abundance.
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landscape composition and configuration affect the abundance of the olive moth Prays Oleae bernard in olive groves
Agriculture Ecosystems & Environment, 2020Co-Authors: Maria Villa, Sonia A P Santos, Jose Paulo Sousa, Alberto Ferreira, Pedro Martins Da Silva, Isabel Patanita, Marta Ortega, Susana Navalpotro Pascual, Jose Alberto PereiraAbstract:Abstract Landscape and crop management are important concepts for conservation biological control as they can influence the abundance of natural enemies. In this work we accomplished a multi-scale study focused on the effect of landscape structure and crop management on the olive moth, Prays Oleae (Bernard), an important pest of the olive tree (Olea europaea L.). The olive moth was collected in different olive groves managed under organic farming and integrated production and surrounded by different landscape structures. Generalized additive mixed models were used to analyze the response of the pest to (i) landscape composition and configuration indices, (ii) the management system and (iii) pesticides applications at different scales. Results indicated that the landscape composition, through the effect of the Simpson’s diversity index, negatively influenced P. Oleae abundance and that the effect was evident at larger scales. Also, the landscape configuration negatively affected P. Oleae at larger scales. However, neither the crop management system nor the pesticide applications affected P. Oleae abundance. This study emphasizes that the preservation or implementation of diverse and complex landscapes can contribute to maintain lower population levels of P. Oleae when compared with homogenous landscape areas.
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are wild flowers and insect honeydews potential food resources for adults of the olive moth Prays Oleae
Journal of Pest Science, 2017Co-Authors: Maria Villa, Albino Bento, Antonio Mexia, Rosalina Marrao, Jose Alberto PereiraAbstract:The use of non-crop resources by natural enemies and their potentialities to enhance their effectiveness as pest control agents is increasing as a method for conservation biological control. Nevertheless, the effect of consumption of non-crop resources by pests has been generally overlooked being this knowledge crucial to favor natural enemies but not pests. In the present work, insect honeydews and flowers suitability as food resources for the olive tree key-pest Prays Oleae were analyzed under laboratory conditions. The selected honeydews were excreted by Saissetia Oleae and Euphyllura olivina, two olive pests, and the selected plants were seven abundant species in the olive grove agroecosystem that bloom simultaneously with the flight period of the anthophagous generation of P. Oleae. In this work, some of these resources were identified as potential food sources for P. Oleae. Despite the general findings, which indicate that honeydews have less nutritional value for insects than nectar, P. Oleae reached the best survival and reproduction performance with the insects’ honeydews. Several of the tested flowers were identified as potential food resources for P. Oleae, being Malva sylvestris the one that originated the best performance. Moreover, our results suggest that P. Oleae females are synovigenic and emerge with nutritional reserves for reproduction. We highly recommend accomplishing further research before establishing these resources in biological control methods in order to confirm their effect on pests in fields.
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ground cover management affects parasitism of Prays Oleae bernard
Biological Control, 2016Co-Authors: Maria Villa, Albino Bento, Sonia A P Santos, Antonio Mexia, Jose Alberto PereiraAbstract:Abstract Spontaneous ground covers comprise ecological infrastructures that may provide food, alternative hosts and shelter for parasitoids in olive groves, thus contributing to biological control of pests. This study investigated the effects of herbicide application, tillage, and conservation of spontaneous ground covers on parasitism of the anthophagous generation of the olive moth, Prays Oleae (Bernard). The study was performed in northeast Portugal in 2011 and 2013 in 14 and 15 olive groves, respectively, with different management types. Generalized Estimating Equations (GEE) were used to analyze olive moth emergence, overall parasitism rate, relative abundance of parasitoid species, and total parasitism of olive moth larvae. Ageniaspis fuscicollis (Dalman) accounted for the majority of the parasitism, followed by Elasmus flabellatus (Fonscolombe). In both years, ground cover management type did not influence the emergence rate of P. Oleae. However, overall parasitism rate, emergence of A. fuscicollis, and the number of A. fuscicollis emerging per olive moth larvae varied among years. In 2011, the latter response variables were significantly higher in groves with spontaneous ground cover than in those treated with herbicide, indicating a negative effect of herbicides on parasitoids. Although tilled groves obtained higher values for these variables in 2013, parasitism rates were generally very low. In sum, the management of ground covers seemed to influence the overall rate of P. Oleae parasitism in some years, but longer-term experiments are needed to clarify this trend.
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effect of soil tillage on natural occurrence of fungal entomopathogens associated to Prays Oleae bern
Scientia Horticulturae, 2013Co-Authors: Ivo Oliveira, Jose Alberto Pereira, Teresa Linoneto, Albino Bento, Enrique Quesadamoraga, Paula BaptistaAbstract:Abstract The olive tree is one of the most important crops in Portugal, where tillage is still a normal practice performed by the growers. This work intends to evaluate the effect of tillage practices on the diversity and abundance of entomopathogenic fungi associated to Prays Oleae Bern. population in the olive grove ecosystem. In order to achieve this, three tilled and three non-tilled groves were sampled for P. Oleae larvae and pupae, during two consecutive years. The fungi were isolated from diseased larvae and pupae and identified by rDNA sequencing. One hundred and twenty isolates of fungi described as entomopathogenic were found, belonging to 8 different species. The most abundant species were Beauveria bassiana (60%), Cladosporium cladosporioides (18%) and Cladosporium oxysporum (14%). Olive groves under no-till system showed higher occurrence (2.7%), diversity (7 species) and abundance (65 isolates) of entomopathogenic fungi than tilled system (2.3%, 4 species and 55 isolates). Although these differences were found to be not significant, the results suggested that no-tilled olive groves with natural vegetation presented the most suitable conditions to increase the probability of P. Oleae infection by entomopathogenic fungi. The highest number of exclusive species found in non-tilled groves (4 species) when compared to tilled ones (1 species) also reinforce this fact and indicated that vegetation cover may act as a reservoir for fungal species.
Albino Bento - One of the best experts on this subject based on the ideXlab platform.
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are wild flowers and insect honeydews potential food resources for adults of the olive moth Prays Oleae
Journal of Pest Science, 2017Co-Authors: Maria Villa, Albino Bento, Antonio Mexia, Rosalina Marrao, Jose Alberto PereiraAbstract:The use of non-crop resources by natural enemies and their potentialities to enhance their effectiveness as pest control agents is increasing as a method for conservation biological control. Nevertheless, the effect of consumption of non-crop resources by pests has been generally overlooked being this knowledge crucial to favor natural enemies but not pests. In the present work, insect honeydews and flowers suitability as food resources for the olive tree key-pest Prays Oleae were analyzed under laboratory conditions. The selected honeydews were excreted by Saissetia Oleae and Euphyllura olivina, two olive pests, and the selected plants were seven abundant species in the olive grove agroecosystem that bloom simultaneously with the flight period of the anthophagous generation of P. Oleae. In this work, some of these resources were identified as potential food sources for P. Oleae. Despite the general findings, which indicate that honeydews have less nutritional value for insects than nectar, P. Oleae reached the best survival and reproduction performance with the insects’ honeydews. Several of the tested flowers were identified as potential food resources for P. Oleae, being Malva sylvestris the one that originated the best performance. Moreover, our results suggest that P. Oleae females are synovigenic and emerge with nutritional reserves for reproduction. We highly recommend accomplishing further research before establishing these resources in biological control methods in order to confirm their effect on pests in fields.
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ground cover management affects parasitism of Prays Oleae bernard
Biological Control, 2016Co-Authors: Maria Villa, Albino Bento, Sonia A P Santos, Antonio Mexia, Jose Alberto PereiraAbstract:Abstract Spontaneous ground covers comprise ecological infrastructures that may provide food, alternative hosts and shelter for parasitoids in olive groves, thus contributing to biological control of pests. This study investigated the effects of herbicide application, tillage, and conservation of spontaneous ground covers on parasitism of the anthophagous generation of the olive moth, Prays Oleae (Bernard). The study was performed in northeast Portugal in 2011 and 2013 in 14 and 15 olive groves, respectively, with different management types. Generalized Estimating Equations (GEE) were used to analyze olive moth emergence, overall parasitism rate, relative abundance of parasitoid species, and total parasitism of olive moth larvae. Ageniaspis fuscicollis (Dalman) accounted for the majority of the parasitism, followed by Elasmus flabellatus (Fonscolombe). In both years, ground cover management type did not influence the emergence rate of P. Oleae. However, overall parasitism rate, emergence of A. fuscicollis, and the number of A. fuscicollis emerging per olive moth larvae varied among years. In 2011, the latter response variables were significantly higher in groves with spontaneous ground cover than in those treated with herbicide, indicating a negative effect of herbicides on parasitoids. Although tilled groves obtained higher values for these variables in 2013, parasitism rates were generally very low. In sum, the management of ground covers seemed to influence the overall rate of P. Oleae parasitism in some years, but longer-term experiments are needed to clarify this trend.
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Plant-mediated effects on entomopathogenic fungi: how the olive tree influences fungal enemies of the olive moth, Prays Oleae
BioControl, 2015Co-Authors: Ivo Oliveira, Albino Bento, José A. Pereira, Teresa Lino-neto, Paula BaptistaAbstract:The community of entomopathogenic fungi associated with the olive moth Prays Oleae is specific for each generation of this insect. The entomopathogen Beauveria bassiana is almost exclusive to the phyllophagous or leaf generation, whereas Paecilomyces formosa mainly occurs in the carpophagous or fruit generation. The main objective of this work was to evaluate olive plant-mediated effects on the development (germination, growth, sporulation and spore viability) of both entomopathogens. While B. bassiana was strongly inhibited by olives, P. formosa development was more restricted by leaves. These inhibitory effects were caused by both volatile and diffusible compounds produced by olives and leaves. Specifically, the effects of two leaf volatile compounds, (Z)-3-hexen-1-ol and (Z)-3-hexenyl acetate were studied. The results suggest that olive plant organs affect entomopathogens by controlling their abundance and function, which may partly explain the occurrence of a fungal species in a specific P. Oleae generation.
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effect of soil tillage on natural occurrence of fungal entomopathogens associated to Prays Oleae bern
Scientia Horticulturae, 2013Co-Authors: Ivo Oliveira, Jose Alberto Pereira, Teresa Linoneto, Albino Bento, Enrique Quesadamoraga, Paula BaptistaAbstract:Abstract The olive tree is one of the most important crops in Portugal, where tillage is still a normal practice performed by the growers. This work intends to evaluate the effect of tillage practices on the diversity and abundance of entomopathogenic fungi associated to Prays Oleae Bern. population in the olive grove ecosystem. In order to achieve this, three tilled and three non-tilled groves were sampled for P. Oleae larvae and pupae, during two consecutive years. The fungi were isolated from diseased larvae and pupae and identified by rDNA sequencing. One hundred and twenty isolates of fungi described as entomopathogenic were found, belonging to 8 different species. The most abundant species were Beauveria bassiana (60%), Cladosporium cladosporioides (18%) and Cladosporium oxysporum (14%). Olive groves under no-till system showed higher occurrence (2.7%), diversity (7 species) and abundance (65 isolates) of entomopathogenic fungi than tilled system (2.3%, 4 species and 55 isolates). Although these differences were found to be not significant, the results suggested that no-tilled olive groves with natural vegetation presented the most suitable conditions to increase the probability of P. Oleae infection by entomopathogenic fungi. The highest number of exclusive species found in non-tilled groves (4 species) when compared to tilled ones (1 species) also reinforce this fact and indicated that vegetation cover may act as a reservoir for fungal species.
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fungal diversity associated to the olive moth Prays Oleae bernard a survey for potential entomopathogenic fungi
Microbial Ecology, 2012Co-Authors: Ivo Oliveira, Jose Alberto Pereira, Teresa Linoneto, Albino Bento, Paula BaptistaAbstract:Olive production is one of the main agricultural activities in Portugal. In the region of Tras-os-Montes, this crop has been considerably affected by Prays Oleae. In order to evaluate the diversity of fungi on Prays Oleae population of Tras-os-Montes olive orchards, larvae and pupae of the three annual generations (phyllophagous, antophagous and carpophagous) were collected and evaluated for fungal growth on their surface. From the 3,828 larvae and pupae, a high percentage of individuals exhibited growth of a fungal agent (40.6%), particularly those from the phyllophagous generation. From all the moth generations, a total of 43 species from 24 genera were identified, but the diversity and abundance of fungal species differed between the three generations. Higher diversity was found in the carpophagous generation, followed by the antophagous and phyllophagous generations. The presence of fungi displaying entomopathogenic features was highest in the phyllophagous larvae and pupae, with Beauveria bassiana as the most abundant taxa. The first report of Beauveria bassiana presence on Prays Oleae could open new strategies for the biocontrol of this major pest in olive groves since the use of an already adapted species increases the guarantee of success of a biocontrol approach. The identification of antagonistic fungi able to control agents that cause major olive diseases, such as Verticillium dahliae, will benefit future biological control approaches for limiting this increasingly spreading pathogen.
Annette Herz - One of the best experts on this subject based on the ideXlab platform.
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Temperature and strain effects on reproduction and survival of Trichogramma Oleae and Trichogramma cacoeciae (Hymenoptera: Trichogrammatidae)
Biocontrol Science and Technology, 2011Co-Authors: Ines Ksentini, Mohieddine Ksantini, Annette Herz, Taieb Jardak, S A HassanAbstract:To assess differences in temperature sensitivity during development, life tables for two lines derived from the species Trichogramma Oleae Voegel+® and Pointel and a strain of Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae) were elaborated at 15, 20, 25, 30, 35, 36, and 37-¦C in the laboratory. Eggs of Ephestia kuehniella Zeller together with a fresh drop of honey were supplied every 2 days until the death of the test females, and the removed host egg batches were placed in the equivalent rearing cabinet. The line ?2F? of T. Oleae was found to be the most efficient at any range of temperatures except at 20 and 37-¦C, in comparison to the other tested strains. For all species, no progeny emerged from eggs incubated at 36-¦C and none of the parasitized eggs turned black at 37-¦C. The better performance at a broader range of temperatures by T. Oleae (line 2 F) might be caused by a shorter history in artificial rearing in comparison to the other strains. Fewer generations at laboratory conditions and frequent multiplication on eggs of its natural host (the olive moth Prays Oleae) may have prevented a deterioration in the rearing population of this strain, maintaining its genetic diversity at a higher scale. Applying varying temperature regimes on the rearing stock at regular intervals during the mass production process may help to maintain the essential quality of the biological control agents for field performance at higher temperaturesAbstract To assess differences in temperature sensitivity during development, life tables for two lines derived from the species Trichogramma Oleae Voegel+® and Pointel and a strain of Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae) were elaborated at 15, 20, 25, 30, 35, 36, and 37-¦C in the laboratory. Eggs of Ephestia kuehniella Zeller together with a fresh drop of honey were supplied every 2 days until the death of the test females, and the removed host egg batches were placed in the equivalent rearing cabinet. The line ?2F? of T. Oleae was found to be the most efficient at any range of temperatures except at 20 and 37-¦C, in comparison to the other tested strains. For all species, no progeny emerged from eggs incubated at 36-¦C and none of the parasitized eggs turned black at 37-¦C. The better performance at a broader range of temperatures by T. Oleae (line 2 F) might be caused by a shorter history in artificial rearing in comparison to the other strains. Fewer generations at laboratory conditions and frequent multiplication on eggs of its natural host (the olive moth Prays Oleae) may have prevented a deterioration in the rearing population of this strain, maintaining its genetic diversity at a higher scale. Applying varying temperature regimes on the rearing stock at regular intervals during the mass production process may help to maintain the essential quality of the biological control agents for field performance at higher temperatures
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Seasonality in the occurrence of two lepidopterous olive pests in Egypt
Insect Science, 2011Co-Authors: Esmat Hegazi, M A Konstantopoulou, Annette Herz, Wedad E Khafagi, E Agamy, Sania Showiel, Atwa Atwa, Gehan M. Abd El-aziz, Safaa M. Abdel-rahmanAbstract:Prays Oleae Bern, (OM) and Palpita unionalis H¨ ub., (JM) are two of the most important pests in olive groves in Egypt. A 3-year monitoring study using sex pheromone trapsinsemi-aridandaridolivegroveswasperformed.Inthesemi-aridgrove,flightpattern of the OM was the same as in other Mediterranean countries, but in dates concordating plantphenology.Themothcompletesthreegenerationsannually:thefirstflightisinMarch to April, the second is in May to June and the third occurs in August to October. In the arid olive grove, an interesting flight pattern was observed. First flight was always very close or overlapped with the second one with no male catches during August to October. However, eggs were present most of the season, indicating unusually high female presence and oviposition activity of the OM during the absence of males in the traps. Generally, moth densities were significantly lower in low fruiting years than in higher ones and were also lower in the arid olive grove than in the semi-arid one. In contrast, JM males were present all season, exhibiting six to seven and three to four overlapping flight peaks in arid and semi-arid olive groves, respectively. Moth densities were significantly higher in the arid olive grove than those in the semi-arid one. This study shows that trapping location and fruit bearing year are characteristics that strongly affect the grove-specific information needed to estimate correctly adult emergence and thus the timing of control measures.
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is mating disruption effective in controlling the olive moth Prays Oleae
Crop Protection, 2009Co-Authors: E M Hegazi, M A Konstantopoulou, Annette Herz, Basilis E Mazomenos, Wedad E Khafagi, E Agamy, Ahmed Zaitun, G Abd M Elaziz, S Showiel, S M AbdelrahmanAbstract:Abstract Field trials were carried out from 2002 to 2004 in an olive grove near Cairo, Egypt, to evaluate the efficacy of mating disruption to control the olive moth, Prays Oleae (Lepidoptera: Yponomeutidae), during the first and second generations. Adding the stabilizer butylhydroxytoluene (BHT) to the β -cyclodextrin ( β -CD)–pheromone complex and using polypropylene tubes as new dispensers maintained an adequate level of pheromone release for >60 days in 2004 vs. ≈10 days in 2002. With this improved application technique and applying the mating disruption at a dose of 40 g active ingredient per ha a few days before the onset of the first flight (“the flower” generation), the inhibition of successful orientation was almost complete (>96%). Moreover, in 2004, significant reductions in fruit fall early in the season ( F = 133.2; df = 2, 12; P = 0.01) and fruit damage late in the season ( F = 34.03; df = 2, 12; P = 0.01) were observed. Also yield/tree was significantly higher ( F = 54.98; df = 2, 12; P = 0.01) in treated trees (105.5 ± 2.4 kg/tree) compared with untreated ones (66.6 ± 3.5 kg/tree). Mating disruption applied on the same olive trees over three years progressively reduced the olive moth population from year to year. The results of 2003–2004 confirm that the principal mechanism of the mating disruption treatment - interference with mate location and reproduction - worked successfully with the pheromone formulation, dose, dispensers and early application of the pheromone. Integration of MD with other biological control methods may also improve the efficacy of this technique.
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field efficiency of indigenous egg parasitoids hymenoptera trichogrammatidae to control the olive moth Prays Oleae lepidoptera yponomeutidae and the jasmine moth palpita unionalis lepidoptera pyralidae in an olive plantation in egypt
Biological Control, 2007Co-Authors: E M Hegazi, Annette Herz, Wedad E Khafagi, E Agamy, Ahmed Zaitun, S A Hassan, Somaia Elsaid, Gehan Abd M Elaziz, Sania Showeil, N KhamisAbstract:Abstract The olive moth, Prays Oleae (Bern.), and the jasmine moth, Palpita unionalis (Hubner), are serious pests in modern olive plantations in Egypt, causing significant yield loss by fruit fall as well as by damage on leaves, flowers and fruits. The egg parasitoid species Trichogramma bourarachae Pintureau and Babault, T. cordubensis Vargas and Cabello, T. euproctidis Girault, all collected in olive groves in Egypt, as well as the commercially available T. evanescens Westwood, originating from sugarcane fields in Egypt, were released in several applications in an intensively managed olive plantation for biological control of these pests. Impact of releases was monitored by recording egg parasitism, pest larval densities, fruit damage and fruit yield. Indigenous Trichogramma species accomplished higher egg parasitism (up to 91%) than the commercial strain. Larval densities of target pests were significantly reduced up to 83% on Trichogramma release trees in comparison to control trees. Fruit damage ranged below 10% infested fruits and fruit yield was significantly increased on trees where indigenous wasps had been applied. The results suggested that releases of the indigenous T. bourarachae, T. cordubensis and T. euproctidis could improve control of lepidopterous pests on olive. The species T. bourarachae was most efficient in dispersal and foraging. Not native to this particular olive plantation before, it could sustainably be established after the releases in 2004. The outcome of this field experiment is encouraging for an efficient use of local Trichogramma spp. and represents a starting point for future optimization of the method.
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Are indigenous strains of Trichogramma sp. (Hym., Trichogrammatidae) better candidates for biological control of lepidopterous pests of the olive tree?
Biocontrol Science and Technology, 2006Co-Authors: Annette Herz, S A HassanAbstract:Abstract Strains of the egg parasitoid, Trichogramma, indigenous in olive groves in the Mediterranean region (T. bourarachae Pintureau & Babault, T. cacoeciae Marchal, T. cordubensis Vargas & Cabello, T. euproctidis Girault, T. nerudai Pintureau & Gerding, T. Oleae Voegele & Pointel) as well as commercially available strains (T. brassicae Bezdenko, T. cacoeciae, T. evanescens Westwood), were assessed in laboratory and semi-field experiments for their attributes as biological control agents for use against lepidopterous olive pests like the olive moth (Prays Oleae Bern.) and the jasmine moth (Palpita unionalis Hubn.). In a choice test, an Egyptian strain of T. cordubensis parasitized significantly more olive and jasmine moth eggs than those of the rearing host Sitotroga cerealella Olivier. This strain was also most efficient in finding eggs of the target pests on olive foliage and on potted olive trees. Survival and fecundity of a Tunisian strain of T. bourarachae was not affected when exposed to hot (35°C...