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Raki Almohamad - One of the best experts on this subject based on the ideXlab platform.

  • aphid honeydew an arrestant and a contact kairomone for Episyrphus balteatus diptera syrphidae larvae and adults
    European Journal of Endocrinology, 2014
    Co-Authors: Pascal Leroy, Quentin Capella, Raki Almohamad, Sabrine Attia, Francois Verheggen
    Abstract:

    Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue for many aphid natural enemies. In the present study, the honeydew excreted by Acyrthosiphon pisum (Harris) was identified as an arrestant and a contact kairomone for young larvae and adults of a common predatory hoverfly, Episyrphus balteatus (De Geer) (Diptera: Syrphidae). First and second instar larvae increased their foraging behaviour in the honeydew-treated area. When plants were sprayed with crude honeydew, the speed of movement of female E. balteatus was significantly higher than in controls, resulting in a longer period of time spent on treated plants and laying eggs. We conclude that the honeydew excreted by A. pisum induces searching behaviour and acts as and arrestant not only for adults but also for young E. balteatus larvae.

  • encounters with aphid predators or their residues impede searching and oviposition by the aphid parasitoid aphidius ervi hymenoptera aphidiinae
    Insect Science, 2014
    Co-Authors: Raki Almohamad, Thierry Hance
    Abstract:

    Intraguild predation (IGP) can be an important factor influencing the effectiveness of aphid natural enemies in biological control. In particular, aphid parasitoid foraging could be influenced by the presence of predators. This study investigated the effect of larvae of the predatory hoverfly Episyrphus balteatus DeGeer (Diptera: Syrphidae) and the multicolored Asian ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) on the foraging behavior of the aphid parasitoid, Aphidius ervi Haliday (Hymenoptera: Aphidiidae) in choice experiments using a leaf disc bioassay. Wasp response to chemical tracks left by those predator larvae was also tested. Parasitoid behavior was recorded using the Observer (Noldus Information Technology, version 5.0, Wageningen, the Netherlands). The experiments were conducted under controlled environmental conditions using leaves of the broad bean plant, Vicia faba L. (Fabaceae) with Myzus persicae Sulzer (Homoptera: Aphididae) as the host complex. A. ervi females avoided aphid patches when larvae of either predator were present. A similar avoidance response was shown by A. ervi to aphid patches with E. balteatus larval tracks, whereas no significant response was observed to tracks left by H. axyridis larvae. It was concluded that IG predator avoidance shown by the aphid parasitoid A. ervi may be a factor affecting their distribution among host patches. © 2013 Institute of Zoology, Chinese Academy of Sciences.

  • Emission of alarm pheromone by non-preyed aphid colonies
    Journal of Applied Entomology, 2008
    Co-Authors: Raki Almohamad, F. J. Verheggen, Frederic Francis, Georges Lognay
    Abstract:

    The sesquiterpene (E)-β-farnesene (Eβf) is the primary component of the alarm pheromone of most aphid species. It is released in response to physical stress including attack by natural enemies and causes aphids to cease feeding and disperse. Eβf also acts as a kairomonal cue for aphid natural enemies. In this study, we collected the headspace volatiles released by aphid colonies of different sizes. Gas chromatography-mass spectrometry analysis demonstrated the presence of Eβf in the absence of predator attack. A quadratic relationship was found between the released (E)-β-farnesene amounts and aphid colony size. Behavioural impact of aphid alarm pheromone towards Episyrphus balteatus female oviposition behaviour was also demonstrated in this work. These results highlight the primary role of the small but continuous release of aphid alarm pheromone in mechanisms of decision-making by aphid predators during their foraging and egg-laying behaviour.

  • evaluation of hoverfly Episyrphus balteatus de geer diptera syrphidae oviposition behaviour toward aphid infested plants using a leaf disc system
    Communications in agricultural and applied biological sciences, 2006
    Co-Authors: Raki Almohamad, Francois Verheggen
    Abstract:

    : Several aphidophagous beneficials such as parasitoids and predators are known to respond positively to aphid infested plants. Semiochemicals from the latter association play an important role in the foraging of predators in a tritrophic approach. In this work, three host plants infested with green peach aphid, Myzus persicae Sulzer were used to study the effect of prey density and aphid colony location on plant toward Episyrphus balteatus female. Their reproductive behaviour and efficiency (in terms of fecundity) were observed in net cages. Three kinds of experiments were performed using a disc leaf on agar diet in small Petri dishes under different conditions: 1) leaf disc of broad bean (Vicia faba) were infested with different aphid prey densities, 2) three host plants (Vicia faba, Solanum tuberosum, Solanum nigrum) infested with 3 different aphid prey densities and 3) three different heights of aphid colony location on V. faba plant infested with constant aphid density were also tested using leaf disc system. Aphid-free leaf discs were also used as control for predator behaviour observations. Oviposition rates of hoverfly on leaf disc system vary significantly with prey aphid densities. The means of eggs per laying were 0.9, 5.3, and 31.2 for 0, 10 and 100 aphid densities respectively. E. balteatus females were also able to evaluate and adjust oviposition rates according to different aphid prey densities/host plant. The 5 and 20 cm stakes were the most attractive heights of aphid colony location for the hoverfly oviposition. The means of eggs per laying were 16.7, 18.5 and 5.8 for 5, 20 and 40cm heights respectively. Our leaf disc system was found to be a practical and efficient way to assess chemical cues from aphids according to different conditions on the hoverfly reproductive behaviour.

  • evaluation of hoverfly Episyrphus balteatus de geer diptera syrphidae oviposition behaviour toward aphid infested plants using a leaf disc system
    Communications in agricultural and applied biological sciences, 2006
    Co-Authors: Raki Almohamad, Francois Verheggen, Frederic Francis, Eric Haubruge
    Abstract:

    : Several aphidophagous beneficials such as parasitoids and predators are known to respond positively to aphid infested plants. Semiochemicals from the latter association play an important role in the foraging of predators in a tritrophic approach. In this work, three host plants infested with green peach aphid, Myzus persicae Sulzer were used to study the effect of prey density and aphid colony location on plant toward Episyrphus balteatus female. Their reproductive behaviour and efficiency (in terms of fecundity) were observed in net cages. Three kinds of experiments were performed using a disc leaf on agar diet in small Petri dishes under different conditions: 1) leaf disc of broad bean (Vicia faba) were infested with different aphid prey densities, 2) three host plants (Vicia faba, Solanum tuberosum, Solanum nigrum) infested with 3 different aphid prey densities and 3) three different heights of aphid colony location on V. faba plant infested with constant aphid density were also tested using leaf disc system. Aphid-free leaf discs were also used as control for predator behaviour observations. Oviposition rates of hoverfly on leaf disc system vary significantly with prey aphid densities. The means of eggs per laying were 0.9, 5.3, and 31.2 for 0, 10 and 100 aphid densities respectively. E. balteatus females were also able to evaluate and adjust oviposition rates according to different aphid prey densities/host plant. The 5 and 20 cm stakes were the most attractive heights of aphid colony location for the hoverfly oviposition. The means of eggs per laying were 16.7, 18.5 and 5.8 for 5, 20 and 40cm heights respectively. Our leaf disc system was found to be a practical and efficient way to assess chemical cues from aphids according to different conditions on the hoverfly reproductive behaviour.

Francois Verheggen - One of the best experts on this subject based on the ideXlab platform.

  • aphid honeydew an arrestant and a contact kairomone for Episyrphus balteatus diptera syrphidae larvae and adults
    European Journal of Endocrinology, 2014
    Co-Authors: Pascal Leroy, Quentin Capella, Raki Almohamad, Sabrine Attia, Francois Verheggen
    Abstract:

    Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue for many aphid natural enemies. In the present study, the honeydew excreted by Acyrthosiphon pisum (Harris) was identified as an arrestant and a contact kairomone for young larvae and adults of a common predatory hoverfly, Episyrphus balteatus (De Geer) (Diptera: Syrphidae). First and second instar larvae increased their foraging behaviour in the honeydew-treated area. When plants were sprayed with crude honeydew, the speed of movement of female E. balteatus was significantly higher than in controls, resulting in a longer period of time spent on treated plants and laying eggs. We conclude that the honeydew excreted by A. pisum induces searching behaviour and acts as and arrestant not only for adults but also for young E. balteatus larvae.

  • evaluation of hoverfly Episyrphus balteatus de geer diptera syrphidae oviposition behaviour toward aphid infested plants using a leaf disc system
    Communications in agricultural and applied biological sciences, 2006
    Co-Authors: Raki Almohamad, Francois Verheggen
    Abstract:

    : Several aphidophagous beneficials such as parasitoids and predators are known to respond positively to aphid infested plants. Semiochemicals from the latter association play an important role in the foraging of predators in a tritrophic approach. In this work, three host plants infested with green peach aphid, Myzus persicae Sulzer were used to study the effect of prey density and aphid colony location on plant toward Episyrphus balteatus female. Their reproductive behaviour and efficiency (in terms of fecundity) were observed in net cages. Three kinds of experiments were performed using a disc leaf on agar diet in small Petri dishes under different conditions: 1) leaf disc of broad bean (Vicia faba) were infested with different aphid prey densities, 2) three host plants (Vicia faba, Solanum tuberosum, Solanum nigrum) infested with 3 different aphid prey densities and 3) three different heights of aphid colony location on V. faba plant infested with constant aphid density were also tested using leaf disc system. Aphid-free leaf discs were also used as control for predator behaviour observations. Oviposition rates of hoverfly on leaf disc system vary significantly with prey aphid densities. The means of eggs per laying were 0.9, 5.3, and 31.2 for 0, 10 and 100 aphid densities respectively. E. balteatus females were also able to evaluate and adjust oviposition rates according to different aphid prey densities/host plant. The 5 and 20 cm stakes were the most attractive heights of aphid colony location for the hoverfly oviposition. The means of eggs per laying were 16.7, 18.5 and 5.8 for 5, 20 and 40cm heights respectively. Our leaf disc system was found to be a practical and efficient way to assess chemical cues from aphids according to different conditions on the hoverfly reproductive behaviour.

  • evaluation of hoverfly Episyrphus balteatus de geer diptera syrphidae oviposition behaviour toward aphid infested plants using a leaf disc system
    Communications in agricultural and applied biological sciences, 2006
    Co-Authors: Raki Almohamad, Francois Verheggen, Frederic Francis, Eric Haubruge
    Abstract:

    : Several aphidophagous beneficials such as parasitoids and predators are known to respond positively to aphid infested plants. Semiochemicals from the latter association play an important role in the foraging of predators in a tritrophic approach. In this work, three host plants infested with green peach aphid, Myzus persicae Sulzer were used to study the effect of prey density and aphid colony location on plant toward Episyrphus balteatus female. Their reproductive behaviour and efficiency (in terms of fecundity) were observed in net cages. Three kinds of experiments were performed using a disc leaf on agar diet in small Petri dishes under different conditions: 1) leaf disc of broad bean (Vicia faba) were infested with different aphid prey densities, 2) three host plants (Vicia faba, Solanum tuberosum, Solanum nigrum) infested with 3 different aphid prey densities and 3) three different heights of aphid colony location on V. faba plant infested with constant aphid density were also tested using leaf disc system. Aphid-free leaf discs were also used as control for predator behaviour observations. Oviposition rates of hoverfly on leaf disc system vary significantly with prey aphid densities. The means of eggs per laying were 0.9, 5.3, and 31.2 for 0, 10 and 100 aphid densities respectively. E. balteatus females were also able to evaluate and adjust oviposition rates according to different aphid prey densities/host plant. The 5 and 20 cm stakes were the most attractive heights of aphid colony location for the hoverfly oviposition. The means of eggs per laying were 16.7, 18.5 and 5.8 for 5, 20 and 40cm heights respectively. Our leaf disc system was found to be a practical and efficient way to assess chemical cues from aphids according to different conditions on the hoverfly reproductive behaviour.

Haubruge Eric - One of the best experts on this subject based on the ideXlab platform.

  • Aphid honeydew: An arrestant and a contact kairomone for Episyrphus balteatus (Diptera: Syrphidae) larvae and adults
    2014
    Co-Authors: Leroy Pascal, Verheggen François, Haubruge Eric, Almohamad Raki, Capella Quentin, Attia Sabrine, Francis Frédéric
    Abstract:

    Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue for many aphid natural enemies. In the present study, the honeydew excreted by Acyrthosiphon pisum (Harris) was identified as an arrestant and a contact kairomone for young larvae and adults of a common predatory hoverfly, Episyrphus balteatus (De Geer) (Diptera: Syrphidae). First and second instar larvae increased their foraging behaviour in the honeydew-treated area. When plants were sprayed with crude honeydew, the speed of movement of female E. balteatus was significantly higher than in controls, resulting in a longer period of time spent on treated plants and laying eggs. We conclude that the honeydew excreted by A. pisum induces searching behaviour and acts as and arrestant not only for adults but also for young E. balteatus larvae.Peer reviewe

  • Occurrence of aphid predator species in both organic and conventional corn and broad bean
    2013
    Co-Authors: Vandereycken Axel, Francis Frédéric, Haubruge Eric, Joie Emilie, Verheggen François
    Abstract:

    Organic farming has been suggested to enhance beneficial species abundance and diversity in agrosystem habitats. In this study, the abundance of aphid predators was compared in organic and conventional corn and broad bean fields during a two-year inventory. In both farming strategies, there were no differences between species diversity. Five aphid predator species were mainly observed: Coccinella septempunctata L. 1758 (Coleoptera: Coccinellidae), Propylea quatuordecimpunctata (L. 1758) (Coleoptera: Coccinellidae), Harmonia axyridis Pallas 1773 (Coleoptera: Coccinellidae), Chrysoperla carnea (Stephens 1836) (Neuroptera: Chrysopidae) and Episyrphus balteatus (De Geer 1776) (Diptera: Syrphidae). Differences in abundance of aphidophagous species between conventional and organic crop fields were observed even if not always in favour of the latter condition. The abundance of the five above- mentioned aphidophagous species varied for the most part according to almost all the observed parameters, including sampled year, crop and agricultural practices. In conclusion, our findings do not support organic practices in corn and broad bean as key options to increase the biodiversity and abundance of aphid natural enemies.Peer reviewe

  • Aphid predators sampling in agrosystems in Belgium between 2009 and 2011
    2012
    Co-Authors: Vandereycken Axel, Haubruge Eric, Durieux Delphine, Joie Emilie, Verheggen François
    Abstract:

    The Multicolored Asian ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was imported in 1997 in Belgium to control aphid populations. Few years ago after its introduction, this exotic insect was well adapted to temperate climate conditions and spread out all over ecosystems in Europe causing decline of other aphidophagous species. In arboreal habitats, H. axyridis is the most dominant Coccinellids but we are still lacking information about this occurrence in agrosystems. An aphidophages sampling between 2009 and 2011 was realized in four agrosystems such as broad bean, wheat, corn and potato. Nevertheless H. axyridis populations rise (5 times) from 2009 to 2011 in 2011, H. axyridis is the third most observed aphidophages after Episyrphus balteatus (De Geer) and Coccinella septempunctata (Linné). H. axyridis is the dominating species in corn with 70.83±6.60 individuals per 100m².Peer reviewe

  • Microorganisms from aphid honeydew attract natural enemies and tending ants
    2012
    Co-Authors: Verheggen François, Lognay Georges, Leroy Pascal, Fischer Christophe, Sabri Ahmed, Heuskin Stéphanie, Thonart Philippe, Fleton Gary, Detrain Claire, Haubruge Eric
    Abstract:

    Aphids are some of the most serious pests of cultivated crops worldwide, causing major yield and economic losses. Previous works have demonstrated ants and natural enemies (including ladybeetles and hoverflies) to be able to use aphid volatile chemicals to locate aphid colonies. Here, we report the first isolation of a bacterium from the pea aphid Acyrthosiphon pisum honeydew, Staphylococcus sciuri, which produces kairomones used by the aphidophagous hoverfly Episyrphus balteatus and the Asian Ladybeetle Harmonia axyridis during their search for prey colonies. Some specific semiochemicals produced by S. sciuri were identified as attractants and ovipositional stimulants. Similarly, we have shown scouts of the aphid tending ant species, Lasius niger, to orientate their foraging behaviour toward an Aphis fabae infested plant and we have demonstrated that the odours released by this aphid honeydew were attractive for ant scouts. Again, bacteria were involved in the production of these honeydew semiochemicals. Interestingly, ant scouts were also able to discriminate honeydew odour from A. fabae (usually attended by L. niger) and A. pisum (unattendedby L. niger). Comparison of the volatile and bacteria composition of both aphid species honeydew were attended

  • Predominant effect of host plant species on Aphis gossypii aphid and Episyrphus balteatus hoverfly in a tritrophic approach
    2011
    Co-Authors: Poligui, René Noël, Francis Frédéric, Haubruge Eric
    Abstract:

    The aphid Aphis gossypii Glover (Homoptera: Aphididae) is known as worldwide important pest. It causes serious injuries to crops, but is also able to feed on various cultivated and wild plants. Some programs are developped to control this aphid. In many studies , hoverfy Episyrphus balteatus De Geer (Diptera : Syrphidae) is used as an efficient and aphid specific predator in biological control systems. In this work, we study cotton aphid choice plant discrimination, the effect of host plants on its developpment(fecondity and mortality), and the E.balteatus foraging and oviposition behavior according aphid host plants. Biologic parameters were observed using various plant combinations. E.balteatus behavioral observations were conducted using the Noldus Observer v.5.0. A.gossypii makes discriminant choice of his hosts, with better preference on Cucurbita pepo L. (Cucurbitaceae) and Capsicum annuum L. (Solanaceae). Dacryodes edulis (G. Don) H.J. Lam. (Burseraceae) and Vicia faba L. (Fabaceae) are the midle choice while Hibiscus sabdariffa L. (Malvaceae) is less chosen. A.gossypii develops easily on C.pepo, and weakly on C.anuum, H.sabdariffa,and V.faba. D. edulis induces very high mortality to A.gossypii. According to E. balteatus behavior, A. gossypii is more attractive when infesting C .pepo and V.faba, less on H. sabdariffa. While non infested , the hoverfly more attractive plant is V.faba. Our results highlited the importance of interactions between aphids and their host plants and the prey-host influence on a specific aphid predatory hoverfy. Suitable ways in correlation with this work are to investigated to complete this study and perform aphids biological control

Santos, Sónia A.p. - One of the best experts on this subject based on the ideXlab platform.

  • Effects of pollen, sugars and honeydew on lifespan and nutrient levels of Episyrphus balteatus
    'Springer Science and Business Media LLC', 2015
    Co-Authors: Pinheiro, Lara A., Torres L., Raimundo João, Santos, Sónia A.p.
    Abstract:

    Hoverflies require pollen, nectar and honeydew during their adult stage, but little is known about the suitability and nutrient provision of each of those resources. Thus, in this study we assessed the effect of different types of food, such as carbohydrates (glucose, fructose, sucrose and honey), pollen, a mixture of honey and pollen, and honeydew on longevity and nutrient levels of Episyrphus balteatus (De Geer) (Diptera: Syrphidae). Glucose and the mixture of pollen and honey were the food sources that gave the highest longevities. Considering nutrient levels in the body of hoverflies, sucrose generated high levels of fructose, total sugars and glycogen while glucose generated high levels of lipids. This suggests that carbohydrates are important food components for the survival and energy supply of hoverflies, with glucose being the most effective. Honeydew can also be used by hoverflies, representing a significant sugar source that may replace nectar when suitable flowers are scarce in agroecosystems.This study was financially supported by FEDER Funds throughout Programa Operacional Factores de Competitividade - COMPETE and National Funds throughout FCT - Fundação para a Ciência e Tecnologia, within the project PTDC/AGR-AAM/100979/2008 - Increasing functional biodiversity in olive groves to enhance conservation biological control of insect pests.info:eu-repo/semantics/publishedVersio

  • Efeito da vegetação herbácea na longevidade e reservas corporais de Episyrphus balteatus (De Geer) (Diptera: Syrphidae)
    2013
    Co-Authors: Pinheiro, Lara A., Torres L., Raimundo João, Benhadi-marín Jacinto, Santos, Sónia A.p.
    Abstract:

    As larvas dos sirfídeos são importantes predadores, especialmente, de espécies pertencentes à ordem Hemiptera. No entanto, os sirfídeos adultos alimentam‐se à base de pólen, néctar e meladas. Entre as plantas herbáceas espontâneas que habitualmente fazem parte da cobertura ou das orlas dos agroecossistemas existem várias espécies com potencial para atraírem sirfídeos e fornecerem alimento. Neste contexto é fundamental esclarecer o efeito dessas plantas e das meladas nas populações de Episyrphus balteatus (De Geer) (Diptera: Syrphidae) de modo a maximizar a sua vitalidade. Com este trabalho pretendeu‐se estudar o efeito de 17 espécies de plantas e de meladas de Saissetia oleae (Oliv.) (Hemiptera: Coccidae) na longevidade e reservas corporais de E. balteatus. As plantas testadas pertenciam às famílias Asteraceae, Apiaceae, Boraginaceae, Brassicaceae, Hypericaceae e Malvaceae. Cada espécie foi colocada à disposição dos indivíduos recém‐emergidos juntamente com água, sendo o controlo mantido apenas com água. Em cada indivíduo foi quantificado o conteúdo corporal de glicogénio, lípidos e açúcares. As plantas que originaram maiores longevidades em E. balteatus foram Malva sylvestris L. (Malvaceae), Foeniculum vulgare L. (Apiaceae), Raphanus raphanistrum L. e Brassica barrelieri (L.) (Brassicaceae), Anchusa azurea Mill. (Boraginaceae), e Crepis vesicaria (Asteraceae), bem como as meladas de S. oleae. A acessibilidade dos nectários, a quantidade de néctar por flor e as diferenças na sua composição podem ter sido os fatores que mais contribuíram para estes resultados. Em termos de pólen, M. sylvestris foi provavelmente a única flor com quantidade suficiente para satisfazer as necessidades nutricionais deste inimigo natural. As meladas de S. oleae mostraram ser outra fonte de açúcar importante para E. balteatus. Estes recursos, quando combinados, são fundamentais para aumentar a abundância e eficácia destes auxiliares, visando a limitação natural dos inimigos da cultura.Fundação para a Ciência e Tecnologia através de fundos nacionais e cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE – Programa Operacional Factores de Competitividade (POFC)

  • Efeito de três açúcares (glicose, frutose e sacarose) na sobrevivência, crescimento e teores de nutrientes corporais de Episyrphus balteatus (De Geer) (Díptera: Syrphidae)
    2012
    Co-Authors: Pinheiro, Lara A., Torres L., Santos, Sónia A.p.
    Abstract:

    Os artrópodes dependem da energia obtida a partir dos hidratos de carbono que podem ser utilizados de forma imediata ou como reserva energética, utilizados posteriormente através da conversão do glicogénio. No caso dos sirfídeos, os hid ratos de carbono são particularmente importantes para estimular a maturação dos ovos nas fêmeas e de uma maneira geral, influenciam a sobrevivência, fecundidade, longevidade e, consequentemente, a efetividade destes inimigos naturais contra pragas da cultura. Com este trabalho pretendeu-se estudar o efeito de três açúcares frequentemente encontrados no néctar das plantas (glicose, frutose e sacarose) na sobrevivência, crescimento e teores de nutrientes corporais de Episyrphus balteatus. Os indivíduos recém-emergidos (

  • Efeito na sobrevivência, crescimento e reservas corporais de Episyrphus balteatus (De Geer) (Diptera: Syrphidae), de cinco espécies da família Asteraceae
    2012
    Co-Authors: Pinheiro, Lara A., Torres L., Santos, Sónia A.p.
    Abstract:

    A dependência dos sirfídeos adultos por pólen e néctar aumenta o potencial para o estabelecimento de flores no ecossistema olivícola e, desta forma, contribui para o incremento da luta biológica contra o algodão-da-oliveira, Euphyllura olivina Costa. A família das Asteraceae é uma das mais referenciadas em termos de preferências alimentares por parte dos sirfídeos, sendo a facilidade de acesso ao recurso floral e a sua fisionomia as principais responsáveis desta atração. Neste contexto é fundamental esclarecer o efeito das Asteraceae nas populações de Episyrphus balteatus (De Geer) (Diptera: Syrphidae) de modo a maximizar a função destes predadores. Com este trabalho pretendeu-se estudar o efeito de cinco espécies de plantas da família Asteraceae (camomila romana (comercial), Coleostephus myconis (L.) Rchb.f., Calendula arvensis L., Crepis vesicaria L., Anthemis arvensis L. ) (1) na sobrevivência, (2) no crescimento e (3) nas reservas corporais de glicogénio, lípidos e açúcares de E. balteatus. As cinco espécies de plantas foram expostas à disposição dos indivíduos recém-emergidos (

  • Efeito na sobrevivência, crescimento e reservas corporais da alimentação de Episyrphus balteatus (De Geer) (Díptera: Syrphidae) com quatro espécies da família Brassicaceae
    2012
    Co-Authors: Pinheiro, Lara A., Torres L., Santos, Sónia A.p.
    Abstract:

    Os sirfídeos desempenham um papel importante no controlo biológico de pragas em diversos ecossistemas. No olival, as larvas são particularmente importantes como predadores naturais de Euphyllura olivina Costa (algodão-da-oliveira). Neste contexto, é fundamental a existência de um complexo paisagístico enriquecido em infra-estruturas ecológicas (polén, néctar, meladas ou presas alternativas) para favorecer uma maior abundância destes inimigos naturais. O conhecimento do efeito das diversas plantas que ocorrem no olival na condição fisiológica dos sirfídeos constitui uma ferramenta de decisão quanto à implementação de uma estratégia de luta biológica de conservação no olival. Com este trabalho pretendeu-se estudar o efeito de quatro espécies de plantas da família das Brassicaceae (Brassica barrelieri L., Bunias erucago L., Raphanus raphanistrum L. e Hirschfeldia incana (L.) Lagr.-Foss.) na sobrevivência, crescimento e teores de nutrientes corporais de Episyrphus balteatus (De Geer) (Díptera: Syrphidae). Assim, os indivíduos recém-emergidos (

Verheggen François - One of the best experts on this subject based on the ideXlab platform.

  • Aphid honeydew: An arrestant and a contact kairomone for Episyrphus balteatus (Diptera: Syrphidae) larvae and adults
    2014
    Co-Authors: Leroy Pascal, Verheggen François, Haubruge Eric, Almohamad Raki, Capella Quentin, Attia Sabrine, Francis Frédéric
    Abstract:

    Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue for many aphid natural enemies. In the present study, the honeydew excreted by Acyrthosiphon pisum (Harris) was identified as an arrestant and a contact kairomone for young larvae and adults of a common predatory hoverfly, Episyrphus balteatus (De Geer) (Diptera: Syrphidae). First and second instar larvae increased their foraging behaviour in the honeydew-treated area. When plants were sprayed with crude honeydew, the speed of movement of female E. balteatus was significantly higher than in controls, resulting in a longer period of time spent on treated plants and laying eggs. We conclude that the honeydew excreted by A. pisum induces searching behaviour and acts as and arrestant not only for adults but also for young E. balteatus larvae.Peer reviewe

  • Occurrence of aphid predator species in both organic and conventional corn and broad bean
    2013
    Co-Authors: Vandereycken Axel, Francis Frédéric, Haubruge Eric, Joie Emilie, Verheggen François
    Abstract:

    Organic farming has been suggested to enhance beneficial species abundance and diversity in agrosystem habitats. In this study, the abundance of aphid predators was compared in organic and conventional corn and broad bean fields during a two-year inventory. In both farming strategies, there were no differences between species diversity. Five aphid predator species were mainly observed: Coccinella septempunctata L. 1758 (Coleoptera: Coccinellidae), Propylea quatuordecimpunctata (L. 1758) (Coleoptera: Coccinellidae), Harmonia axyridis Pallas 1773 (Coleoptera: Coccinellidae), Chrysoperla carnea (Stephens 1836) (Neuroptera: Chrysopidae) and Episyrphus balteatus (De Geer 1776) (Diptera: Syrphidae). Differences in abundance of aphidophagous species between conventional and organic crop fields were observed even if not always in favour of the latter condition. The abundance of the five above- mentioned aphidophagous species varied for the most part according to almost all the observed parameters, including sampled year, crop and agricultural practices. In conclusion, our findings do not support organic practices in corn and broad bean as key options to increase the biodiversity and abundance of aphid natural enemies.Peer reviewe

  • Aphid predators sampling in agrosystems in Belgium between 2009 and 2011
    2012
    Co-Authors: Vandereycken Axel, Haubruge Eric, Durieux Delphine, Joie Emilie, Verheggen François
    Abstract:

    The Multicolored Asian ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was imported in 1997 in Belgium to control aphid populations. Few years ago after its introduction, this exotic insect was well adapted to temperate climate conditions and spread out all over ecosystems in Europe causing decline of other aphidophagous species. In arboreal habitats, H. axyridis is the most dominant Coccinellids but we are still lacking information about this occurrence in agrosystems. An aphidophages sampling between 2009 and 2011 was realized in four agrosystems such as broad bean, wheat, corn and potato. Nevertheless H. axyridis populations rise (5 times) from 2009 to 2011 in 2011, H. axyridis is the third most observed aphidophages after Episyrphus balteatus (De Geer) and Coccinella septempunctata (Linné). H. axyridis is the dominating species in corn with 70.83±6.60 individuals per 100m².Peer reviewe

  • Microorganisms from aphid honeydew attract natural enemies and tending ants
    2012
    Co-Authors: Verheggen François, Lognay Georges, Leroy Pascal, Fischer Christophe, Sabri Ahmed, Heuskin Stéphanie, Thonart Philippe, Fleton Gary, Detrain Claire, Haubruge Eric
    Abstract:

    Aphids are some of the most serious pests of cultivated crops worldwide, causing major yield and economic losses. Previous works have demonstrated ants and natural enemies (including ladybeetles and hoverflies) to be able to use aphid volatile chemicals to locate aphid colonies. Here, we report the first isolation of a bacterium from the pea aphid Acyrthosiphon pisum honeydew, Staphylococcus sciuri, which produces kairomones used by the aphidophagous hoverfly Episyrphus balteatus and the Asian Ladybeetle Harmonia axyridis during their search for prey colonies. Some specific semiochemicals produced by S. sciuri were identified as attractants and ovipositional stimulants. Similarly, we have shown scouts of the aphid tending ant species, Lasius niger, to orientate their foraging behaviour toward an Aphis fabae infested plant and we have demonstrated that the odours released by this aphid honeydew were attractive for ant scouts. Again, bacteria were involved in the production of these honeydew semiochemicals. Interestingly, ant scouts were also able to discriminate honeydew odour from A. fabae (usually attended by L. niger) and A. pisum (unattendedby L. niger). Comparison of the volatile and bacteria composition of both aphid species honeydew were attended

  • Field evaluation of survival rates of Harmonia axyridis (Coleoptera: Coccinellidae) and other aphidophagous species
    2011
    Co-Authors: Vandereycken Axel, Haubruge Eric, Durieux Delphine, Joie Emilie, Verheggen François
    Abstract:

    The multicoloured Asian ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae), previously introduced as a biological control agent against aphids, is now frequently considered as an intraguild predator, consuming other aphids natural enemies. Interactions between this exotic ladybird and the other aphidophagous species present in Belgian agro-ecosystems such as Coccinella septempunctata, Episyrphus balteatus, Chrysoperla carnea are asymmetric to the benefit of H. axyridis. Many studies have already shown its predatory behaviour. This study focuses on the survival rate of three aphidophagous species Harmonia axyridis (Ha), Coccinella septempunctata (C7) and Episyrphus balteatus (Eb) in biological fields of potato and sugar beet. During June and July, hermetic cages were disposed on the crops with 10 larvae (second stage) of each aphidophagous. There were 4 combinations of insects placed inside the cages (1) Ha+Eb+C7+ aphids, (2) Ha+Eb+C7, (3) Eb+C7+ aphids and (4) Eb+C7. Each combination was repeated three times. Aphids (Aphis fabae) were added in excess when needed. In sugar beet fields, E. balteatus was the species with the highest mortality rate. The two coccinellid species had a better survival rate than E. balteatus. All aphidophagous species had higher mortality rates in absence of aphids. In potato, the survival rate of all aphidophagous was lower than sugar beet when aphids were present in excess probably because A. fabae reproduced less in potato. Nevertheless, we have observed in potato no mortality of C. 7-punctata during all its development cycle. This suggests that C. 7-punctata could use more efficiently aphids as food sources than H. axyridis. In potato and sugar beet, H. axyridis had the longest development cycle, being still at the larval stage when C. 7-punctata and E. balteatus reached the pupae stage. We can suppose that pupae of E. balteatus and C. 7-punctata were an alternative food (intraguild prey) to H. axyridis when aphids were lacking. Pupae are immobile and therefore more sensitive to the attack of predators.Peer reviewe