References of "Francis, Frédéric"
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See detailImpact of aphid alarm pheromone release on virus transmission efficiency: when pest control strategy could induce higher virus dispersion
Lin, Fang-Jing; Bosquée, Emilie ULg; Liu, Ying-Jie et al

in Journal of Virological Methods (2016)

Aphids cause serious damages to crops not only by tacking sap but also by transmitting numerous viruses. To develop biological control, the aphid alarm pheromone, namely E-β-farnesene (EβF), has been ... [more ▼]

Aphids cause serious damages to crops not only by tacking sap but also by transmitting numerous viruses. To develop biological control, the aphid alarm pheromone, namely E-β-farnesene (EβF), has been demonstrated to be efficient to repel aphids and as attract beneficials, making it a potential tool to control aphid pests. Considering aphids also as virus vectors, changes of their behaviour could also interfere with the virus acquisition and transmission process. Here, a combination of two aphid species and two potato virus models were selected to test the influence of EβF release on aphid and virus dispersion under laboratory conditions. EβF release was found to significantly decrease the population of M. persicae and M. euphorbiae around the infochemical releaser but simultaneously also increasing the dispersal of Potato Virus Y (PVY). At the opposite, no significant difference for Potato Leaf Roll Virus (PLRV) transmission efficiency was observed with similar aphid alarm pheromone releases for none of the aphid species. These results provide some support to carefully consider infochemical releasers not only for push – pull strategy and pest control but also to include viral disease in a the plant protection to aphids as they are also efficient virus vectors. Impact of aphid kinds and transmission mechanisms will be discussed according to the large variation found between persistent and non persistent potato viruses and interactions with aphids and related infochemicals. [less ▲]

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See detailCrop residue management in arable cropping systems under temperate climate. Part 1: Soil biological and chemical (phosphorus and nitrogen) properties. A review
Lemtiri, Aboulkacem ULg; Degrune, Florine ULg; Barbieux, Sophie ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016)

Interacting soil organisms support biological processes that participate in soil functions, organic matter decomposition, and nutrient cycling. Earthworms and microorganisms play a range of beneficial ... [more ▼]

Interacting soil organisms support biological processes that participate in soil functions, organic matter decomposition, and nutrient cycling. Earthworms and microorganisms play a range of beneficial roles in agricultural systems, including increased organic matter mineralization, nutrient cycling, and soil structure stabilization. The following aspects of crop residue management effects are examined in this paper: (i) earthworm composition and structure; (ii) soil microbial communities; and (iii) phosphorus (P) and nitrogen (N) element availability and distribution in the soil profile. Conventional tillage (ploughing) is often reported to generate decreased soil organism abundance and diversity, primarily earthworms and microorganisms, as well as a uniform distribution of the nutrients P and N within the ploughed soil horizon. Soil residue incorporation of mineral particles can maintain P and N levels, however returning soil also increases aeration and the activation of microbial activity. Hence, comparisons of tillage effects on soil biological functioning and nutrient cycling remain unclear. This review highlights the challenges in establishing definitive evidence regarding the effects of crop residue management on soil organisms and nutrient dynamics. The studies examined reported variability in soil and climate, and the complexity of soil processes contributed to the absence of clear findings. Further research is required under temperate climate conditions. [less ▲]

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See detailEffect of wheat-based intercropping systems on pests and natural enemies: a review with a special focus on China
Hatt, Séverin ULg; Chevalier Mendes Lopes, Thomas ULg; Xu, Qingxuan ULg et al

Conference (2016, April 16)

Intercropping is a farming practice consisting of cultivating at least two plant species simultaneously in the same field, but without necessarily sowing and/or harvesting them at the same time. By ... [more ▼]

Intercropping is a farming practice consisting of cultivating at least two plant species simultaneously in the same field, but without necessarily sowing and/or harvesting them at the same time. By increasing plant diversity at the field scale, intercropping may be an efficient method to control insect pests and support natural enemies on the associated crops. We performed a systematic research of the peer-reviewed literature which studied the effect of intercropping systems on pests and natural enemies, compared to pure stands. The research was restricted to wheat-based systems, as it is an important crop worldwide, and the main one in Northern China. A total of fifty research papers were obtained from the literature search. Results from a vote-counting analysis, using binomial tests, indicated that pest abundance was significantly reduced in intercropping systems compared with pure stands, but their natural enemies were not particularly favoured (i.e., predators and parasitoids). Among these papers, 23 were studies from China. There, wheat was associated with cotton in relay-intercropping, as well as alfalfa, chili peppers, fava bean, garlic, mung bean, oilseed rape and pea in strip-cropping. Aphids were systematically reduced and natural enemies (i.e., predators and parasitoids) significantly favoured in intercropping systems compared to pure stands. This study shows that intercropping is a viable practice to biologically control pests, and potentially support natural enemies, especially in China. Therefore it can be seen as a viable method to reduce insecticide use in wheat production systems. [less ▲]

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See detailInventaire et mise en collection d’espèces de pucerons et de parasitoïdes collectés en grandes cultures, et premier enregistrement de Metopolophium frisicum (Hille Ris Lambers 1947) et Acyrthosiphon primulae (Theobald 1913) (Hemiptera: Aphididae) en Belgique
Chevalier Mendes Lopes, Thomas ULg; Hatt, Séverin ULg; Starý, Petr et al

in Entomologie Faunistique = Faunistic Entomology (2016), 69

The purpose of this study was to identify aphid and parasitoid species that were collected in wheat and pea crops situated in Gembloux (Belgium), and conserve them into collections. To do so, yellow traps ... [more ▼]

The purpose of this study was to identify aphid and parasitoid species that were collected in wheat and pea crops situated in Gembloux (Belgium), and conserve them into collections. To do so, yellow traps (von Moericke) were used during 2012, 2013 and 2014 growing seasons. Fifty-two aphid species were identified and conserved in the entomological Conservatory of Gembloux. Among them, Metopolophium frisicum (Hille Ris Lambers 1947) and Acyrthosiphon primulae (Theobald 1913) were officially referenced for the first time in Belgium. Moreover, a collection composed by 16 parasitoid species was created. Their interest for biological control, as well as the methods that are studied in the laboratory of functional and evolutionary Entomology from Gembloux Agro-Bio Tech (University of Liège) to promote their presence in crops are discussed. [less ▲]

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See detailHistopathological effects of Aspergillus clavatus (Ascomycota: Trichocomaceae) on larvae of the southern house mosquito, Culex quinquefasciatus (Diptera: Culicidae)
Bawin, Thomas ULg; Seye, Fawrou; Boukraa, Slimane ULg et al

in Fungal Biology (2016), 120(4), 489-499

Aspergillus clavatus (Ascomycota: Trichocomaceae) was previously found to be an opportunistic pathogen of mosquitoes (Diptera: Culicidae). In the present study, the mechanism leading to its insecticidal ... [more ▼]

Aspergillus clavatus (Ascomycota: Trichocomaceae) was previously found to be an opportunistic pathogen of mosquitoes (Diptera: Culicidae). In the present study, the mechanism leading to its insecticidal activity was investigated regarding histological damages on Culex quinquefasciatus larvae exposed to A. clavatus spores. Multiple concentration assays using spore suspensions (0.5 x 10^8 to 2.5 x 10^8 spores/ml) revealed 17.0% to 74.3% corrected mortalities after 48 h exposure. Heat-deactivated spores induced a lower mortality compared to non-heated spores suggesting that insecticidal effects are actively exerted. Spore-treated and untreated larvae were prepared for light microscopy as well as for scanning and transmission electron microscopy. Spores failed to adhere to the external body surface (except the mouth parts) of these aquatic immature stages but progressively filled the digestive tract where their metabolism seemed to activate. In parallel, the internal tissues of the larvae, i.e. the midgut wall, the skeletal muscles, and the cuticle-secreting epidermis, were progressively destroyed between 8 and 24 h of exposure. These observations suggest that toxins secreted by active germinating spores of A. clavatus in the digestive tract altered the larval tissues, leading to their necrosis and causing larval death. Fungal proliferation and sporulation then occurred during a saprophytic phase. A. clavatus enzymes or toxins responsible for these pathogenic effects need to be identified in further studies before any use of this fungus in mosquito control. [less ▲]

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See detailEFFECT OF EXTRACTION pH ON PHYSICO-CHEMICAL, ENZYMATIC AND TECHNOLOGICAL PROPERTIES OF CRUDE EXTRACTS FROM WILD CARDOON (CYNARA CARDUNCULUS L.) FLOWERS
BEN AMIRA, Amal; BESBES, Souhail; ATTIA, Hamadi et al

Conference (2016, March 22)

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See detailChecklist of Aphidiinae (Hymenoptera: Braconidae) and Aphelinus (Hymenoptera: Aphelinidae) species from Belgium with respectively four and three new records
Chevalier Mendes Lopes, Thomas ULg; Libert, Pierre-Nicolas; Starý, Petr et al

in Zootaxa (2016), 4092(4)

Aphid parasitoids have good potential for crop protection. However, they have been poorly studied in Belgium, especially in terms of species diversity. Therefore, the aim of this work was to establish the ... [more ▼]

Aphid parasitoids have good potential for crop protection. However, they have been poorly studied in Belgium, especially in terms of species diversity. Therefore, the aim of this work was to establish the first checklist for the country. To complete the list, aphid parasitoids were sampled in wheat and pea fields near Gembloux (Belgium), in 2013 and 2014. Among the identified species, Aphelinus asychis Walker, Aphelinus daucicola Kurdjumov, Aphelinus fusciscapus (Förster), Aphidius asteris Haliday, Aphidius eadyi Starý, Gonzalez & Hall, Praon barbatum Mackauer, and Trioxys auctus (Haliday) were recorded for the first time in Belgium. Thirty-two Aphidiinae and seven Aphelinus species were included in the checklist. It is hoped this study will stimulate further research, as species diversity is still low compared with neighbouring countries. [less ▲]

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See detailProduction of two entomopathogenic Aspergillus species and insecticidal activity against the mosquito Culex quinquefasciatus compared to Metarhizium anisopliae
Bawin, Thomas ULg; Seye, Fawrou; Boukraa, Slimane ULg et al

in Biocontrol Science & Technology (2016), 26(5), 617-629

Entomopathogenic micro-organisms including fungi have become increasingly studied for integrated pest management. The spore productivity and insecticidal activity of two opportunistic insect pathogenic ... [more ▼]

Entomopathogenic micro-organisms including fungi have become increasingly studied for integrated pest management. The spore productivity and insecticidal activity of two opportunistic insect pathogenic Aspergillus species (namely: Aspergillus clavatus Desmazieres and Aspergillus flavus Link (Ascomycota: Eurotiales, Trichocomaceae)) were compared to Metarhizium anisopliae sensu lato (Metchnikoff) Sorokin (Ascomycota: Hypocreales, Clavicipitaceae) for mosquito (Diptera: Culicidae) control. The production of aerial spores on wheat bran and white rice was investigated in solid-, semi-solid-, and liquid-state media supplemented with a nutritive solution. Wheat bran-based media were suitable for spore production and increased the spore yield in solid-state from 3 to 7 fold: A. clavatus produced 48.4 ± 5.2 and 15.7 ± 1.6 x 10^8 spores/g, A. flavus produced 22.3 ± 4.1 and 3.1 ± 2.5 x 10^8 spores/g, and M. anisopliae produced 39.6 ± 6.5 and 13.1 ± 2.6 x 10^8 spores/g of wheat bran or white rice, respectively. A. clavatus, A. flavus and M. anisopliae spores harvested from wheat bran-based solid-state media showed lethal concentrations (LC50) of 1.1, 1.8, and 1.3 x 10^8 spores/ml against Culex quinquefasciatus Say larvae in 72 h. Because A. clavatus and M. anisopliae displayed similar features when cultured under these conditions, our results suggest that insect pathogenic Aspergillus species may be as productive and virulent against mosquito larvae as a well-recognized entomopathogenic fungus. Wheat bran could advantageously be used in large-scale fermentation for a possible cost-effective pest control using these fungi. [less ▲]

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See detailSURVEYS OF APHIDS AND POTATO VIRUS Y IN POTATO FIELDS IN WALLONIA, BELGIUM: A FOUR YEAR OVERVIEW
Bosquée, Emilie ULg; Yattara, Almouner A.; Crutzen, François et al

in Journal of Plant Pathology [=JPP] (2016)

Populations of Potato virus Y (PVY) and aphids were characterized in potato seed and stock production fields in southern Belgium (Wallonia) from 2009 to 2012. More than 40 aphid species were identified ... [more ▼]

Populations of Potato virus Y (PVY) and aphids were characterized in potato seed and stock production fields in southern Belgium (Wallonia) from 2009 to 2012. More than 40 aphid species were identified using yellow pan traps. Four thousands potato leaf samples collected in 87 plots from 29 fields were analysed for the presence and typing of PVY strains by RT-PCR. PVY was detected in 26%, 20% and 60% of the seed plots tested from 2009 to 2011, respectively. A higher prevalence of PVY was observed in plots of stock potatoes (60% in 2010 and 67% in 2011). The N/NTN strain of PVY was predominant, representing 70-99% of the strains. [less ▲]

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See detailForaging wireworms are attracted to root-produced volatile aldehydes
Barsics, Fanny ULg; Delory, Benjamin M.; Delaplace, Pierre ULg et al

in Journal of Pest Science (2016)

Soil-dwelling insects are known to react to chemical cues they encounter in the rhizosphere. Whether wireworms (Coleoptera, Elateridae) use root-emitted volatile organic chemicals to localize their host ... [more ▼]

Soil-dwelling insects are known to react to chemical cues they encounter in the rhizosphere. Whether wireworms (Coleoptera, Elateridae) use root-emitted volatile organic chemicals to localize their host plant remains, however, poorly understood. Here, we aimed at identifying chemical cues released by barley roots that attract Agriotes sordidus. In a first behavioral experiment, we assessed the ability of wireworms to orient towards live barley roots, using dual-choice olfactometers suitable for belowground insects. Then, we collected the volatile organic compounds (VOC) produced by barley roots using a dynamic head-space sampling approach. VOC were quantified and identified using gas chromatography—mass spectrometry (GC–MS). The odorant blend is composed of four aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-2-enal, and (E,Z)-nona-2,6-dienal. In a second set of dual-choice bioassays, wireworms were attracted towards a synthetic blend of these four major compounds. However, the synthetic blend was not as attractive as live roots, which is partially explained by the absence of CO2, commonly known as a strong attractant for soil-dwelling insects. While CO2 indicates the presence of living material in the vicinity, we hypothesize that additional VOC inform about the plant suitability. A better understanding of these belowground signals would contribute to the development of new integrated control strategies against wireworms. [less ▲]

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See detailDiversity and ecology survey of mosquitoes potential vectors in Belgian equestrian farms: A threat prevention of mosquito-borne equine arboviruses
Boukraa, Slimane ULg; de la Grandière, Maria Ana ULg; Bawin, Thomas ULg et al

in Preventive Veterinary Medicine (2016), 124

Emergence of West Nile Virus was recently recorded in several European countries, which can lead to severe health problems in horse populations. Europe is also at risk of introduction of mosquito-borne ... [more ▼]

Emergence of West Nile Virus was recently recorded in several European countries, which can lead to severe health problems in horse populations. Europe is also at risk of introduction of mosquito-borne equine alphavirus from Americas. Prevention of these arboviruses requires a clear understanding of transmission cycles, especially their vectors. To characterize mosquito fauna, their ecology and identify potential vectors of equine arboviruses in Belgium, entomological surveys of six equestrian farms located in the Wolloon Region were conducted during 2011–2012. The harvest of mosquitoes was based on larval sampling (272 samples from 111 breeding sites) and monthly adults trapping (CO2-baited traps, Mosquito Magnet Liberty Plus). Among 51,493 larvae and 319 adult mosquitoes collected, morphological identification showed the presence of 11 species: Anopheles claviger (Meigen), An. maculipennis s.l. (Meigen), An. plumbeus (Stephens), Culex hortensis (Ficalbi), Cx. territans (Walker), Cx. pipiens s.l. L., Cx. torrentium (Martini), Coquillettidia richiardii (Ficalbi), Culiseta annulata (Schrank), Aedes cantans (Meigen), Ae. geniculatus (Olivier). Molecular identification of Cx. pipiens species complex allowed the detection of three molecular forms, Pipiens (92.3%), Molestus (4.6%) and Hybrid (3.1%). Larvae of Cx. pipiens sl and Cx. torrentium were omnipresent and the most abundant species. Water troughs, ponds and slurry (liquid manure) were the most favorable breeding sites of mosquito larvae. Based upon behavior and ecology of the identified mosquito species, Studied Belgian equestrian farms seem to provide a suitable environment and breeding sites for the proliferation of potential vectors of arboviruses and those being a real nuisance problem for horses and neighboring inhabitants. [less ▲]

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See detailFirst survey on prevalence and infestation rates of Varrroa mite in Gabon
Fabre Anguilet, Edgard ULg; Alabi, Taofic ULg; Bengone Ndong, Toussaint et al

in Communications in Agricultural and Applied Biological Sciences (2016), 81(3), 299-305

Varroa mites cause considerable damage to Apis mellifera Linnaeus colonies in North America, Europe and Asia. To control this parasite, beekeepers in these parts of world have to use chemical acaricides ... [more ▼]

Varroa mites cause considerable damage to Apis mellifera Linnaeus colonies in North America, Europe and Asia. To control this parasite, beekeepers in these parts of world have to use chemical acaricides. In Africa, this pest has been identified, and survey of Varroa infestation rates showed a lot of variation across honey bee sub-species. Generally, African colonies seemed to be resistant or tolerant to the presence of Varroa mite. The objective of our study is to explore the presence, prevalence and infestation rates of Varroa mite in Gabon. The presence and quantitative assessment of Varroa mites were performed in 55 wild colonies of Apis mellifera adansonii Latreille in two locations. Our results showed that: (1) 70% and 48% of the wild colonies studied were infested with Varroa destructor according to locations, (2) Varroa infestation rate was lower than 0.5 mite per 100 bees regardless location. The infestation rates obtained were still very low compared to those observed in various other regions in Africa. In perspective, it would be interesting to explore the reasons that could explain the low infestation rates which were observed. [less ▲]

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See detailGrasshoppers as a food source? A review
Paul, Aman ULg; Frederich, Michel ULg; Uyttenbroeck, Roel ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016), 20(AgricultureIsLife), 337-352

Description of the subject. Current trends suggest an increasing future demand for conventional meats, which indicates a strong need to shift this dependency to other alternative protein sources such as ... [more ▼]

Description of the subject. Current trends suggest an increasing future demand for conventional meats, which indicates a strong need to shift this dependency to other alternative protein sources such as insects. Literature. From a nutritional point of view, of all the insects consumed globally, grasshoppers are particularly important as a human food. Data from the literature regarding the nutrient composition, amino acid profile, fatty acid profile, mineral composition and vitamin content of grasshoppers as reviewed in this paper, suggest that a number of grasshopper species are a good source of nutrients. It also highlights some of the health related aspects that might arise from the consumption of grasshoppers, mostly linked to agricultural practices and the allergic response of sensitive individuals. The paper also summarizes some religious, social and economic factors that are associated with grasshopper consumption. Conclusions. The success of introducing grasshoppers as a novel food in western countries depends on changes in consumer attitudes. It would be interesting to develop food products derived from grasshoppers in a form acceptable to consumers. Furthermore, it is important to explore the food potential of some grasshopper species native to western countries and to develop their rearing methodologies to enhance availability. [less ▲]

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See detailTowards sustainable food systems: the concept of agroecology and how it questions current research practices. A review
Hatt, Séverin ULg; Artru, Sidonie ULg; Brédart, David ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016), 20(Special issue 1), 215-224

Introduction. Multiple environmental and socio-economic indicators show that our current agriculture and the organization of the food system need to be revised. Agroecology has been proposed as a ... [more ▼]

Introduction. Multiple environmental and socio-economic indicators show that our current agriculture and the organization of the food system need to be revised. Agroecology has been proposed as a promising concept for achieving greater sustainability. This paper offers an overview and discussion of the concept based on existing literature and case studies, and explores the way it questions our current research approaches and education paradigms. Literature. In order to improve the sustainability of agriculture, the use of external and chemical inputs needs to be minimized. Agroecological farming practices seek to optimize ecological processes, thus minimizing the need for external inputs by providing an array of ecosystem services. Implementing such practices challenges the current structure of the food system, which has been criticized for its lack of social relevance and economic viability. An agroecological approach includes all stakeholders, from field to fork, in the discussion, design and development of future food systems. This inclusion of various disciplines and stakeholders raises issues about scientists and their research practices, as well as about the education of the next generation of scientists. Conclusions. Agroecology is based on the concept that agricultural practices and food systems cannot be dissociated because they belong to the same natural and socio-economic context. Clearly, agroecology is not a silver-bullet, but its principles can serve as avenues for rethinking the current approaches towards achieving greater sustainability. Adapting research approaches in line with indicators that promote inter- and transdisciplinary research is essential if progress is to be made. [less ▲]

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See detailPros and cons of flowers strips for farmers. A review
Uyttenbroeck, Roel ULg; Hatt, Séverin ULg; Paul, Aman ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016), 20(s1), 225-235

Description of the subject. To counteract environmental problems due to agricultural intensification, European farmers can apply agri-environmental schemes in their fields. Flower strips are one example ... [more ▼]

Description of the subject. To counteract environmental problems due to agricultural intensification, European farmers can apply agri-environmental schemes in their fields. Flower strips are one example of these schemes, with the aim of supporting biodiversity, leading to an increase in “useful” species groups such as pollinators for crop pollination and natural enemies for pest control. However, to our knowledge, a complete appraisal of the pros and cons of flower strips, from a farmer’s point of view, does not yet exist. It is proposed that better and more complete information could increase the adoption and implementation of such agri-environmental schemes. Objectives. This study aims 1) to assess the pros and cons of flower strips, from a farmer’s point of view, and 2) to highlight the knowledge gaps that exist in the scientific literature, for the different types of pros and cons. Method. We listed the different components of the appraisal of pros and cons and conducted a systematic screening of the scientific literature on flower strips and these components. Results. The largest part of the 31 selected studies was concerning agronomical and ecological processes, such as pollination and animal pest control. Most of them indicated positive effects of flower strips. For many components of the appraisal, mostly economic and social ones, few or no studies were found. Conclusions. While a positive balance of pros and cons, from a farmer’s point of view, came from our literature screening, large research gaps still remain and more research is required, especially in the economic and social components of the evaluation. [less ▲]

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See detailWheat (Triticum aestivum L.)-based intercropping systems for biological pest control: a review
Chevalier Mendes Lopes, Thomas ULg; Hatt, Séverin ULg; Xu, Qingxuan ULg et al

in Pest Management Science (2016), 72

BACKGROUND: Wheat (Triticum aestivum L.) is one of the most cultivated crops in temperate climates. As its pests are mainly controlled with insecticides which are harmful to the environment and human ... [more ▼]

BACKGROUND: Wheat (Triticum aestivum L.) is one of the most cultivated crops in temperate climates. As its pests are mainly controlled with insecticides which are harmful to the environment and human health, alternative practices such as intercropping have been studied for their potential to promote biological control. Based on the published literature, this study aimed to review the effect of wheat-based intercropping systems on insect pests and their natural enemies. RESULTS: Fifty original research papers were obtained from a systematic search of the peer-reviewed literature. Results from a vote-counting analysis indicated that, in the majority of studies, pest abundance was significantly reduced in intercropping systems compared with pure stands. However, the occurrence of their natural enemies as well as predation and parasitism rates were not significantly increased. The country where the studies took place, the type of intercropping, and the crop that was studied in the association had significant effects on these results. CONCLUSION: These findings show that intercropping is a viable practice to decrease insecticide use in wheat production systems. Nevertheless, other practices could be combined with intercropping to favour natural enemies and enhance pest control. [less ▲]

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See detailEffects of Plant Defense Signal Molecules Jasmonic Acid and Salicylic Acid on the Expression of Detoxification Enzyme Glutathione S-transferases and Salivary Protein C002 in Myzus persicae
ZHANG, Yong; FAN, Jia; ZHAO, XingYan et al

in SCIENTIA SINICA Vitae (2016), 46(5), 665-672

Jasmonic acid (JA) and salicylic acid (SA) are important phytohormones for activating plant defense responses when plants suffer from mechanical damage or pest infestation. In response to plant defense ... [more ▼]

Jasmonic acid (JA) and salicylic acid (SA) are important phytohormones for activating plant defense responses when plants suffer from mechanical damage or pest infestation. In response to plant defense responses, insects usually increase the detoxification enzyme activity or secrete some saliva proteins into plants to modulate host cell processes to promote their adaptation. In this study, we used real-time qPCR to detect the relative gene expression of detoxification enzyme named glutathione S-transferases (sigma GST) and salivary gland-specific protein C002 in Myzus persicae after feeding with 5mM JA or 10mM SA through artificial diet. The results showed that the relative expression of sigma GST and C002 in M. persicae increased significantly after JA and SA treatments. The results revealed that M. persicae can use JA and SA as cues to up-regulate gene expression of related detoxification enzyme and saliva protein. Our results provided new insights into the research on the mechanism of M. persicae adaptation to host plant resistance. [less ▲]

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See detailBacteria may contribute to distant species recognition in ant–aphid mutualistic relationships
Fischer, Christophe ULg; Detrain, Claire; Thonart, Philippe ULg et al

in Insect Science (2016)

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 ... [more ▼]

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. [less ▲]

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