Occurrence de la coccinelle asiatique (Harmonia axyridis Pallas), la coccinelle à 7 points (Coccinella septempunctata L.), le syrphe ceinturé (Episyrphus balteatus De Geer) et la chrysope (Chrysoperla sp.) au sein d’agro-écosystèmes wallons

Poster (2010, November 06)

Development of biological control formulations incorporating components of plant origin

in Journée Scientifique annuelle de la Société Royale de Chimie: Jeudi 14 octobre 2010, Gembloux Agro-Bio Tech, Université de Liège, Chimie verte (2010, October 14)

Semiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been considered within various integrated pest management IPM strategies. Herein, two sesquiterpenoids: E-β ... [more ▼]

Semiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been considered within various integrated pest management IPM strategies. Herein, two sesquiterpenoids: E-β-farnesene and E-β-caryophyllene have been formulated for their potential properties as aphid enemies attractants. Indeed, E-β-farnesene, the alarm pheromone of many aphid species [1], has also been identified as a kairomone by attracting and inducing oviposition of aphid predators (Episyrphus balteatus De Geer (Diptera: Syrphidae)) [2-5] and by attracting aphid parasitoids (Aphidius ervi Haliday (Hymenoptera: Braconidae)) [6, 7]. E-β-caryophyllene was identified as a potential component of the aggregation pheromone of the Asian ladybird, Harmonia axyridis Pallas [8, 9]. The two products have been purified from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae) [10, 11]. Natural and biodegradable slow-release devices have been investigated in order to deliver these molecules. Moreover, due to their sensitivity to oxidation, the sesquiterpenes needed to be protected. For this purpose, alginate (hydrophilic matrix with low oxygen permeability) was used as polymer for the formulations: the main objective was to hold and deliver semiochemical substances in a controlled way. Consequently, a careful selection of alginates was realised for encapsulation. Formulated beads showed different structural and encapsulation properties depending on factors such as polymer concentration, ionic strength, type and concentration of cross-linker ion,... The gel structure influenced diffusion properties. Alginate formulations were characterized by texturometry and by confocal microscopy in order to observe the distribution of semiochemicals in alginate network. The last step consisted in studying release rate of semiochemicals in laboratory-controlled conditions by adapted trapping and Fast-GC procedures [10,11]. [less ▲]

Volatile collection of cadaveric compounds

Poster (2010, October 14)

Thanatochemistry, also named ''chemistry of death'', is poorly studied and the available information regarding the volatile organic compounds (cadaveric VOCs) released after death are rather limited ... [more ▼]

Thanatochemistry, also named ''chemistry of death'', is poorly studied and the available information regarding the volatile organic compounds (cadaveric VOCs) released after death are rather limited. Thanks to the use of analytical chemistry methods ((TDS)GC-MS, GCxGC-TOF-MS), the olfactive signature of a dead body may be studied during the decomposition process. Different volatile collection techniques are used to study the smell of death. There are passive sampling techniques (Radiello® diffusive sampler) and dynamic sampling technique (pump device). The smell of death is constituted by a blend of hundreds of volatile organic compounds which change during the decay process. Main products detected are sulphur compounds such as sulphur dioxide, dimethyldisulfide and dimethyltrisulfide; alcools (1-butanol, 3-methyl-1-butanol), acids (butanoic acid, 2-methylbutanoic acid, 3-methylbutanoic acid and propanoic acid). Many cyclic hydrocarbons were detected: indole, phenol, p-cresol and piperidin-2-one are some examples. The aldehydes are also present, overall butanal, hexanal, heptanal and nonanal. We however found no trace of cadaverine or putrescine. Our results may have potential implication in a better understanding of the olfactive signature of a human or animal cadaveric corpse. Especially in the field of forensic entomology, these chemical compounds may have an attractive role on the necrophagous insect behaviour. Further studies based on the relationships that may exist between cadaveric VOCs and necrophagous insects are currently conducted at the Department of functional and evolutionary Entomology (GxABT, Ulg). [less ▲]

Study of the life cycle of two species of forensic interest carrion beetles (Coleoptera, Silphidae): Thanatophilus sinuatus F. & Necrodes littoralis L.

in 17 th Benelux Congress of Zoology: Classic Biology in Modern Times: Programme and Abstracts (2010, October)

Biological control formulations incorporating essential oils' components

in Lochynski, Stanislaw; Wawrzenczyk, Czeslaw (Eds.) 41th International Symposium on Essential Oils - Programme and Book of Abstracts (2010, September)

Alarm pheromones: Chemical signaling in response to danger

in Litwack, Gerald (Ed.) Pheromones (2010)

Many animals respond to the threat of predation by producing alarm signals that warn other individuals of the presence of danger or otherwise reduce the success of predators. While alarm signals may be ... [more ▼]

Many animals respond to the threat of predation by producing alarm signals that warn other individuals of the presence of danger or otherwise reduce the success of predators. While alarm signals may be visual or auditory as well as chemical, alarm pheromones are common, especially among insects and aquatic organisms. Plants too emit chemical signals in response to attack by insect herbivores that recruit the herbivores’ natural enemies and can induce preparations for defense in neighboring plants (or other parts of the same plant). In this chapter we discuss our current understanding of chemical alarm signaling in a variety of animal groups (including social and pre-social insects, marine invertebrates, fish, and mammals) and in plants. We also briefly discuss the exploitation of alarm pheromones as foraging cues for natural enemies. We conclude with a brief discussion of the potential exploitation of alarm signaling to achieve the applied goal of managing pest species. [less ▲]

Involvement of odorant cues in the process of superparasitism avoidance

Poster (2010, August)

Les Silphidae...de nouveaux bio-indicateurs en entomologie forensique?

in VII Conférence Internationale Francophone d'Entomologie: Interactions et Biodiversité (2010, July 09)

Occurrence de la coccinelle asiatique, Harmonia axyridis Pallas, dans les agro-écosystèmes wallons

Conference (2010, July 06)

Etude des populations de staphylins (Coleoptera : Staphylinidae) au sein de l’écosystème-cadavre

Poster (2010, July)