References of "Heuskin, Stéphanie"
     in
Bookmark and Share    
Peer Reviewed
See detailA pheromone-based formulation against phytophagous pests
Fassotte, Bérénice ULg; Vandereycken, Axel ULg; Heuskin, Stéphanie ULg et al

Poster (2014, April 02)

Innovative integrated pest management methods are needed to overcome market withdrawal of synthetic pesticides. Therefore, the identification of environment-friendly bio-products carrying direct or ... [more ▼]

Innovative integrated pest management methods are needed to overcome market withdrawal of synthetic pesticides. Therefore, the identification of environment-friendly bio-products carrying direct or indirect biocide activity is one promising alternative option. Our researches focus on the identification of appropriate formulations releasing volatile organic compounds that are attractive for natural enemies of insect pests. However, the elaboration of slow-release devices that ensure stable and controlled release of active volatile compounds is quite challenging. Here, we developed a formulation based on E-β-farnesene and (–)-β-caryophyllene, these two semiochemicals having strong attractive potential on aphid natural enemies including ladybeetles and hoverflies. Both compounds were encapsulated together in alginate gel beads. The blend efficiency is currently being evaluated through laboratory and field assays. [less ▲]

Detailed reference viewed: 14 (3 ULg)
Full Text
See detailSome Interesting Sources of Plant Seed Oil
Paul, Aman ULg; Danthine, Sabine ULg; Blecker, Christophe ULg et al

Poster (2014, March 05)

There is a growing realization worldwide that biodiversity is fundamental to agricultural production and food security, as well as a valuable ingredient of environmental conservation. Flowering strips ... [more ▼]

There is a growing realization worldwide that biodiversity is fundamental to agricultural production and food security, as well as a valuable ingredient of environmental conservation. Flowering strips around the border of the crops serves as an important function to improve the biodiversity, besides this they play a major role in the ruminant nutrition and serve as a source of numerous beneficial compounds. It is well known that seeds store their food reserves for next generation mainly in the form of lipids; some of the seeds from these flowering strips could be an interesting source of lipids. These seed oils could play important role in food, pharmaceutical, cosmetics and other industries. The extraction of seed oil from four such plant species in Belgium namely Oregano (Origanum vulgare), Yellow Bedstraw (Galium verum), Common Self-heal (Prunella vulgaris) & Purple loosestrife (Lythrum salicaria) was carried out. Extraction was done by a cold extraction technique using chloroform/methanol in 2:1 ratio as solvent. Amount of oil extracted from Oregano, Yellow Bedstraw, Common Self-heal and Purple loosestrife was 22.58±0.03 %, 3.28±0.01 %, 14.84±0.12 % & 20.32±0.15 %. The fatty acid profiles of these four species were determined by gas chromatography (using methyl esters of their fatty acids); Oleic acid and Linoleic acid were found in all the four species, Gamma-linolenic acid was found in Purple loosestrife & Alpha-linolenic acid was found in Oregano and Common Self-heal plant species. Thermal behaviour of these four plant seed oils were analyzed using Differential Scanning Calorimetry (DSC), while some other physicochemical properties of the seed oils were also analyzed. These plant seed oils can be of great commercial importance. [less ▲]

Detailed reference viewed: 33 (16 ULg)
Peer Reviewed
See detailThe facultative bacterial symbiont Serratia symbiotica in Acyrtosiphon pisum confer resistance to Aphidius ervi
Attia, Sabrine; Foray, Vincent; Louâpres, Philippe et al

Poster (2014)

Detailed reference viewed: 15 (4 ULg)
Peer Reviewed
See detailDoes the facultative bacteria Serratia symbiotica influence the foraging strategies of aphid parasitoids?
Attia, Sabrine; Louâpre, Philippe; Foray, Vincent et al

Poster (2014)

Detailed reference viewed: 10 (0 ULg)
Full Text
See detailL'étude des sémiochimiques. Applications en écologie chimique
Heuskin, Stéphanie ULg

Scientific conference (2013, November 21)

Detailed reference viewed: 6 (0 ULg)
Full Text
See detailDéveloppements analytiques appliqués à une thématique d'écologie chimique
Heuskin, Stéphanie ULg

Scientific conference (2013, February)

Detailed reference viewed: 9 (0 ULg)
Full Text
Peer Reviewed
See detailDissecting the mechanisms underlying old male mating advantage in a butterfly
Karl, Isabell; Heuskin, Stéphanie ULg; Fischer, Klaus

in Behavioral Ecology and Sociobiology (2013)

Selection is expected to maximize an individual’s own genetic reward regardless of the potential fitness consequences for its sexual partners, which may cause sexual conflict. Although performance in ... [more ▼]

Selection is expected to maximize an individual’s own genetic reward regardless of the potential fitness consequences for its sexual partners, which may cause sexual conflict. Although performance in holometabolous insects typically diminishes with age, old male mating advantage has been documented in a few species. Whether this pattern arises from female preference for older males based on, e.g., pheromone blends (intersexual selection), or from increased eagerness to mate in older compared to younger males is currently debated. We explore the mechanistic basis of old male mating advantage, using a series of experiments including behavioral as well as manipulative approaches, in the tropical butterfly Bicyclus anynana. Consistent with the residual reproductive value hypothesis, old male mating advantage was associated with a greater eagerness to mate, evidenced by a two times higher flying and courting activity in older than in younger males. In contrast, we found only limited support for a contribution of female preference for older males based on pheromone composition, although male sex pheromones clearly do play a role in mating success. Our results suggest that male behavior may play a primary role in old male mating advantage, and that pheromones are likely of secondary importance only. Male mating success was related to higher overall pheromone titers rather than variation in a single component. A dominant importance of male behavior in determining mating success may result in sexual conflict. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailThe scent of inbreeding: male sex pheromones betray inbred males
van Bergen, Erik; Brakefield, Paul M.; Heuskin, Stéphanie ULg et al

in Proceedings of the Royal Society B : Biological Sciences (2013)

Inbreeding depression results from mating among genetically related individuals and impairs reproductive success. The decrease in male mating success is usually attributed to an impact on multiple fitness ... [more ▼]

Inbreeding depression results from mating among genetically related individuals and impairs reproductive success. The decrease in male mating success is usually attributed to an impact on multiple fitness-related traits that reduce the general condition of inbred males. Here, we find that the production of the male sex pheromone is reduced significantly by inbreeding in the butterfly Bicyclus anynana. Other traits indicative of the general condition, including flight performance, are also negatively affected in male butterflies by inbreeding. Yet, we unambiguously show that only the production of male pheromones affects mating success. Thus, this pheromone signal informs females about the inbreeding status of their mating partners. We also identify the specific chemical component, hexadecanal, probably responsible for the decrease in male mating success. Our results advocate giving increased attention to olfactory communication as a major causal factor of mate-choice decisions and sexual selection. [less ▲]

Detailed reference viewed: 8 (1 ULg)
Full Text
Peer Reviewed
See detailAnalysis of the diastereoisomers of alliin by HPLC
DETHIER, Bérénice ULg; Laloux, Morgan ULg; Hanon, Emilien et al

in Talanta (2012), 101

Garlic has been known for its therapeutic effects for centuries and is used worldwide as a functional food. The concentration of the active molecules could be enhanced by a better knowledge of their ... [more ▼]

Garlic has been known for its therapeutic effects for centuries and is used worldwide as a functional food. The concentration of the active molecules could be enhanced by a better knowledge of their biosynthesis. The precursor of these compounds, alliin (a sulfur amino-acid) has been obtained by chemical synthesis. However, this synthesis route also leads to a diastereoisomer as co-product. This work describes the development of an analytical method which allows the separation and quantification of the two diastereoisomers in order to determine in which proportion the natural form can be produced. The HPLC method which was optimized and validated by accuracy profile exploits an original stationary phase consisting of porous graphitic carbon (PGC). Furthermore, the developped method was used to separate the diastereoisomers of methiin, another garlic cysteine sulfoxide, and to analyse and aqueous extract of garlic. The ability to quantify the amount of natural alliin is valuable for further work on garlic molecules and their application for health protection. [less ▲]

Detailed reference viewed: 62 (23 ULg)
Full Text
Peer Reviewed
See detailHoneydew volatile emission acts as a kairomonal message for the Asian lady beetle Harmonia axyridis (Coleoptera: Coccinellidae)
Leroy, Pascal; Heuskin, Stéphanie ULg; Sabri, Ahmed ULg et al

in Insect Science (2012), 19(4), 498-506

The Asian lady beetle Harmonia axyridis Pallas is considered as an invasive species in most territories where it has been introduced. Because aphid honeydew acts as an attractant for many aphid predators ... [more ▼]

The Asian lady beetle Harmonia axyridis Pallas is considered as an invasive species in most territories where it has been introduced. Because aphid honeydew acts as an attractant for many aphid predators and parasitoids, the objectives of this work were to collect and identify the volatile compounds released from the aphid excretory product to evaluate how these semiochemicals could affect the H. axyridis foraging behavior. Twelve volatile chemicals were identified from the Megoura viciae Buckton honeydew including four alcohols, three ketones, three aldehydes, a pyrazine and a monoterpene. The volatiles 3-methyl-1-butanol and 3-methyl-butanal were highlighted as the two most abundant semiochemicals released from the M. viciae honeydew. Vicia faba L. plants treated with crude honeydew attracted more than 80% of the tested individuals with 40% of attracted beetles located on the plant. Four volatile compounds (3-hydroxy-2-butanone, 3-methyl-butanal, 3-methyl-1-butanol and limonene) were also highlighted to attract more than 75% of the coccinellids toward the odor source and to locate about 35% of them on the plants. Limonenewas the most efficient attractant since 89% of the H. axyridis responded to this odor. The use of the identified semiochemicals aswell as the composition of an artificial honeydew could certainly be helpful to control the dispersal of the Asian lady beetle H. axyridis. [less ▲]

Detailed reference viewed: 63 (26 ULg)
Peer Reviewed
See detailDevelopment of semiochemical slow-release formulations as biological control devices
Heuskin, Stéphanie ULg; Lorge, Stéphanie ULg; Leroy, Pascal ULg et al

Poster (2012, July)

Semiochemicals have been widely considered within various integrated pest management (IPM) strategies. In the present work, two sesquiterpenoids, E-β-farnesene and E-β-caryophyllene, were formulated for ... [more ▼]

Semiochemicals have been widely considered within various integrated pest management (IPM) strategies. In the present work, two sesquiterpenoids, E-β-farnesene and E-β-caryophyllene, were formulated for their related properties as aphid enemy attractants. E-β-farnesene, the alarm pheromone of many aphid species, was also identified as a kairomone of aphid predators (Episyrphus balteatus De Geer (Diptera: Syrphidae)) and parasitoids (Aphidius ervi Haliday (Hymenoptera: Braconidae)). E-β-caryophyllene was identified as a potential component of the aggregation pheromone of the Asian ladybird, Harmonia axyridis Pallas, another aphid predator. The two products were purified from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae) for E-β-farnesene and E-β-caryophyllene, respectively. Natural and biodegradable slow-release formulations were then investigated in order to deliver these molecules on crop fields for a long period of time as biological control devices. Due to their sensitivity to oxidation, both sesquiterpenes needed to be protected from degradation. For this purpose, alginate – hydrophilic matrix with low oxygen permeability – was used as polymer for the formulations: the main objective was to deliver semiochemical substances in the air in a controlled way. Consequently, a careful selection of alginates was realised. Formulated beads showed different structural and encapsulation properties depending on various formulation factors. Alginate formulations were characterized by texturometry and by confocal microscopy in order to observe the distribution of semiochemicals in alginate network. The last step of alginate bead characterisation consisted in studying release rate of semiochemicals in laboratory-controlled conditions by optimised trapping and validated Fast-GC procedures. Finally, the efficiency of formulations as aphid predator (Syrphidae) and parasitoid (A. ervi) attractants was demonstrated by field trapping and olfactometry experiments. [less ▲]

Detailed reference viewed: 81 (10 ULg)
Peer Reviewed
See detailExpanding on olfactory communication in a butterfly: cuticular chemicals indicate sex and age in Bicyclus anynana
Heuskin, Stéphanie ULg; Kaltenpoth, M.; Engl, T. et al

in International Society of Chemical Ecology, 28th Annual Meeting. Abstracts (2012, July)

Chemical (olfactory or gustatory) communication is fundamental to most living organisms but widely understudied compared to other channels of communication such as vision and audition, principally in ... [more ▼]

Chemical (olfactory or gustatory) communication is fundamental to most living organisms but widely understudied compared to other channels of communication such as vision and audition, principally in sexual selection . Here we present the first extensive analysis of cuticular chemical diversity in a butterfly, and investigate whether molecules inform potential mating partners about sex and age. Bicyclus anynana was chosen for its well-known potentialities as a lab model in eco-evo-devo studies , . Chemical interactions have been investigated so far in this species with focus on volatile olfactory components: male sexual pheromones composition and their roles in sexual selection , , their change in ratio with male age, inbreeding coefficient, and other factors . Here we aim completing the picture fully and focus on gustatory non-volatile cuticular chemical diversity in this model species. Indeed, as for Drosophila, the courtship of this butterfly is composed of a series of steps that include short-range interactions during which various chemicals may be involved in mate-choice, through olfactory but also gustatory channels of communication (Nieberding et al., data not published). More than hundred cuticular chemicals were identified and quantified by GC-MS analyses on different parts (abdomen, antennae, head, legs and wings) of B. anynana individuals (n=42, 210 GC-MS analyses) of each sex and at different ages (from 1 to 21 days old). The analysis of the chemical distribution was realised by multivariate statistical analyses (perMANOVA). The results led to the conclusion that some cuticular chemicals are indicative for the body parts and can inform about sex and age. [less ▲]

Detailed reference viewed: 53 (2 ULg)
Full Text
Peer Reviewed
See detailA Semiochemical Slow-release Formulation in a Biological Control Approach to Attract Hoverflies
Heuskin, Stéphanie ULg; Lorge, Stéphanie ULg; Leroy, Pascal ULg et al

in Journal of Environment and Ecology (2012), 3(1), 72-85

E-β-Farnesene, the alarm pheromone of many aphid species, and E-β-caryophyllene are considered as two sesquiterpenes attractive for aphid predators, among which Syrphidae species. Both compounds were ... [more ▼]

E-β-Farnesene, the alarm pheromone of many aphid species, and E-β-caryophyllene are considered as two sesquiterpenes attractive for aphid predators, among which Syrphidae species. Both compounds were formulated in alginate gel beads as slow-release devices in a biological control approach against aphids. Semiochemical diffusion from beads was studied in the laboratory according to abiotic parameters. Efficiency of formulations as hoverfly attractant was demonstrated in field experiments from June to August 2009. The diffusion of semiochemicals from alginate bead formulations was principally limited by high values (>85%) of relative humidity in the air. Temperature also impacts the release of volatile compounds. In field experiments, these two abiotic factors were supposed to highly condition the trapping of hoverflies. These field trappings demonstrated the efficiency of both semiochemical formulations compared to control (formulation without semiochemical) to catch females of Syrphidae during three months. [less ▲]

Detailed reference viewed: 46 (12 ULg)
Full Text
See detailA new HPLC method to quantify alliin, the major sulfur compound in garlic
DETHIER, Bérénice ULg; Laloux, Morgan ULg; Hanon, Emilien et al

Poster (2012, February 10)

Garlic is recognized for centuries for its health benefits, mostly linked to its sulfur- components. Among the products extracted from the cloves, alliin retained our attention. Alliin was synthesized ... [more ▼]

Garlic is recognized for centuries for its health benefits, mostly linked to its sulfur- components. Among the products extracted from the cloves, alliin retained our attention. Alliin was synthesized. This process leads to two stereoisomers. Their HPLC separation was the aim of this work. The method described in the literature (amino column, detection at 210 nm) showed a resolution of 1,1 between the isomers. A second method was developed: the stationary phase was porous graphitic carbon and a water-ACN gradient was used for the elution. It provided a resolution of 3,2, was shorter and underwent the validation process. The method leads to satisfying results. The separation is excellent, and the validation criteria are fulfilled. This may be valuable for future research on garlic. [less ▲]

Detailed reference viewed: 40 (9 ULg)
Full Text
See detailDéveloppements analytiques appliqués à une thématique d'écologie chimique
Heuskin, Stéphanie ULg

Scientific conference (2012, February)

Detailed reference viewed: 7 (0 ULg)
See detailMicroorganisms from aphid honeydew attract natural enemies and tending ants
Verheggen, François ULg; Leroy, Pascal; Fischer, Christophe ULg et al

Conference (2012, February)

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 ... [more ▼]

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. [less ▲]

Detailed reference viewed: 37 (7 ULg)
Full Text
Peer Reviewed
See detailFast-GC quantifacation of harmonine, the major defense alkaloid of the multicolored Asian ladybird Harmonia axyridis (Pallas)
Fischer, Christophe ULg; Laurent, Pascal ULg; Heuskin, Stéphanie ULg et al

in American Journal of Analytical Chemistry (2012), 3

These last few years the multicolored Asian ladybird, Harmonia axyridis (Pallas), previously introduced in Europe and North America as a biological control agent, has swiftly spread out on those ... [more ▼]

These last few years the multicolored Asian ladybird, Harmonia axyridis (Pallas), previously introduced in Europe and North America as a biological control agent, has swiftly spread out on those territories and turns out to be a pest in several ways. In order to improve understanding of several key points of the biology of this ladybird, a novel fast-GC method of quantification of harmonine, the main defense alkaloid of H. axyridis, has been designed and validated using the accuracy profile concept for concentrations ranging from 13 to 264 µg/individual. This method allows quantifying harmonine in a single insect with a maximal error risk of 20%. For ladybirds collected in spring, mean harmonine concentration observed was 106.6 µg/individual with a very high standard deviation of 80.2 µg/individual, which can easily be explained by the strong asymmetry of the results distribution. Males and females seem equally chemically protected as the harmonine concentration did not significantly differ between sexes. This method is currently used to improve our comprehension of several key points of H. axyridis biology including aggregation behavior and aposematism. [less ▲]

Detailed reference viewed: 68 (6 ULg)
Full Text
Peer Reviewed
See detailTesting semiochemicals from aphid, plant and conspecific: attraction of Harmonia axyridis
Leroy, Pascal ULg; Schillings, Thomas ULg; Farmakidis, Julien ULg et al

in Insect Science (2012), 19

Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is an invasive specie affecting the dynamics and composition of several guilds. Nowadays, no biological control method is available to reduce the ... [more ▼]

Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is an invasive specie affecting the dynamics and composition of several guilds. Nowadays, no biological control method is available to reduce the populations of this harmful coccinellid. Attractants and semiochemicals seem to be the best alternative but only few studies have tested the impact of semiochemicals on this Asian lady beetle. In this work, through wind-tunnel experiments, semiochemicals from aphids [Z,E-nepetalactone, (E)-β-farnesene, α-pinene and β-pinene], from coccinellids [(-)-β-caryophyllene] and from the nettle Urtica dioica L. were envisaged as potential attractants. The nettle volatile compounds [(Z)-3-hexenol and (E)-2-hexenal] were extracted using a Clevenger Apparatus® and identified by headspace-GC-MS. The main components of the aphid alarm pheromone as well as a component of the aphid sexual pheromone strongly attracted both sexes of the Asian lady beetle while (-)-β-caryophyllene only attracted few individuals and had no impact on the males. The nettle extract as well as the (Z)-3-hexenol oriented both males and females to the odour source. The (E)-2-hexenal was showed to have no effect on females even if this green leaf volatile attracted males. This study highlighted that some semiochemicals from aphids and from nettle extracts orientated the harlequin ladybird H. axyridis. These volatile compounds could certainly help for an efficient biological control approach against this invasive specie. [less ▲]

Detailed reference viewed: 108 (48 ULg)