References of "Verheggen, François"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailAttraction of wireworms towards root-emitted volatile organic compounds of barley
Barsics, Fanny ULg; Latine, Rémi ULg; Haubruge, Eric ULg et al

Poster (2011, August)

Wireworms (Coleoptera: Elateridae) are soil dwelling pests of many crops. Aldrin and lindane used to provide satisfactory treatment levels of infested lands. Their withdrawal from the market for ... [more ▼]

Wireworms (Coleoptera: Elateridae) are soil dwelling pests of many crops. Aldrin and lindane used to provide satisfactory treatment levels of infested lands. Their withdrawal from the market for environmental issues gave birth to new needs in terms of management. In order to enhance integrated management of this pest, we work on the chemical ecology of Agriotes sordidus Illiger. We focus on its interaction with barley roots, mediated by volatile organic compounds (VOCs). Our experimentations are based on behavioural responses of wireworms in olfactometric devices and their statistical relevance [less ▲]

Detailed reference viewed: 35 (12 ULg)
Full Text
Peer Reviewed
See detailThe chemical ecology of Harmonia axyridis
Sloggett, John; Magro, Alexandra; Verheggen, François ULg et al

in BioControl (2011), 56

We review the chemical ecology of the ladybird beetle Harmonia axyridis from the perspective of its invasiveness and the deleterious effects it exerts in the regions it has colonised. We outline the ... [more ▼]

We review the chemical ecology of the ladybird beetle Harmonia axyridis from the perspective of its invasiveness and the deleterious effects it exerts in the regions it has colonised. We outline the nature and quantification of its chemical defence, and discuss the protection this provides against natural enemies, particularly intraguild predators. We consider the role of infochemicals in location of prey, intraspecific communication and intraguild interactions. We also discuss the role of prey allelochemicals in relation to H. axyridis extreme dietary generalism. Harmonia axyridis poses a number of practical problems for human health and well-being, including “ladybug taint” wine contamination and problems resulting from large aggregations overwintering in buildings. We consider chemical insights into these issues and, in particular, how attractants and repellents might help manage H. axyridis populations through a push–pull strategy. We conclude by discussing future perspectives for research. [less ▲]

Detailed reference viewed: 37 (7 ULg)
Full Text
Peer Reviewed
See detailMicroorganisms from aphid honeydew attract natural enemies and tending ants
Verheggen, François ULg; Leroy, Pascal; Fischer, Christophe ULg et al

Conference (2011, August)

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: 89 (8 ULg)
Full Text
Peer Reviewed
See detailChemical and physical factors involved in the aggregation behaviour of Harmonia axyridis Pallas
Durieux, Delphine ULg; Fischer, Christophe ULg; Deneubourg, Jean-Louis et al

Conference (2011, July 27)

Detailed reference viewed: 49 (7 ULg)
Peer Reviewed
See detailHost location by the parasitoid, Nasonia vitripennis Walker (Hymenoptera : Pteromalidae)
Frederickx, Christine ULg; Durieux, Delphine ULg; Verheggen, François ULg et al

Poster (2011, July 24)

Successful reproduction for parasitoids encompasses a series of behavioral steps commonly defined as host-habitat location, host location, host acceptance and host regulation. Successful host location ... [more ▼]

Successful reproduction for parasitoids encompasses a series of behavioral steps commonly defined as host-habitat location, host location, host acceptance and host regulation. Successful host location, where resources are patchily distributed within the environment, is dependent on the information value of stimuli used in the host location process. Chemical cues produced by either the host itself, products derived from the host play an important role in host location. This study investigated the role of odorant cues used during host location by the generalist parasitoid, Nasonia vitripennis Walker. N vitripennis is a common parasitoid of Dipteran pupae found in association with decaying carrion. The biological activity of eight of the volatile molecules constituting the odour of pupae were tested on the searching behavior of parasitoid females through chemoecological approache: olfactometry bioassays. [less ▲]

Detailed reference viewed: 53 (14 ULg)
Full Text
Peer Reviewed
See detailEarthworms use odor cues to locate and feed on microorganisms in soil
Zirbes, Lara ULg; Mark, Mescher; Vrancken, Véronique ULg et al

in PLoS ONE (2011), 6(7), 21927

Detailed reference viewed: 56 (13 ULg)
Full Text
Peer Reviewed
See detailWireworms use barley root volatile chemicals to locate their host plant in soil
Barsics, Fanny ULg; Latine, Rémi ULg; Haubruge, Eric ULg et al

Poster (2011, July)

Wireworms (Coleoptera: Elateridae) are soil dwelling pests of many crops. Aldrin and lindane used to provide satisfactory treatment levels of infested lands. Their withdrawal from the market for ... [more ▼]

Wireworms (Coleoptera: Elateridae) are soil dwelling pests of many crops. Aldrin and lindane used to provide satisfactory treatment levels of infested lands. Their withdrawal from the market for environmental issues gave birth to new needs in terms of management. In order to enhance integrated management of this pest, we work on the chemical ecology of Agriotes sordidus Illiger. We focus on its interaction with barley roots, mediated by volatile organic compounds (VOCs). Our experimentations are based on behavioural responses of wireworms in olfactometric devices and their statistical relevance. [less ▲]

Detailed reference viewed: 56 (10 ULg)
Full Text
Peer Reviewed
See detailOptimisation of a semiochemical slow-release alginate formulation attractive towards Aphidius ervi Haliday parasitoids
Heuskin, Stéphanie ULg; Lorge, Stéphanie; Godin, Bruno et al

in Pest Management Science (2011)

BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E-β-farnesene and E-β-caryophyllene) slow-release devices in biological control approaches by attracting ... [more ▼]

BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E-β-farnesene and E-β-caryophyllene) slow-release devices in biological control approaches by attracting predators and parasitoids of aphids. Various formulation criteria were optimised with respect to semiochemical encapsulation capacity. Moreover, the optimised formulation was characterised by texturometry and confocal microscopy. The slow-release rates of semiochemicals were calculated in laboratory controlled conditions. The attractiveness of semiochemical formulations towards Aphidius ervi was demonstrated by olfactometry. RESULTS: Two major parameters were highlighted in encapsulation optimisation: the type of alginate (Sigma L) and the type of crosslinker ion (Ca2+). Other formulation parameters were optimised: ionic strength (0.5M), Ca2+ (0.2 M) and alginate (1.5%) concentrations and the maturation time of beads in CaCl2 solution (48 h). After physical characterisation of beads, semiochemical slow-release measurements showed that alginate formulations were efficient sesquiterpene releasers, with 503 μg of E-β-farnesene and 1791 μg of E-β-caryophyllene totally released in 35 days. The efficiency of semiochemical alginate beads as attractants for female parasitoids was demonstrated, with high percentages of attraction for semiochemical odours (88 and 90% for E-β-farnesene and E-β-caryophyllene respectively) and significant statistical results. CONCLUSION: Semiochemical alginate beads can be considered as efficient slow-release systems in biological control. These formulations could be very useful to attract aphid parasitoids on crop fields. [less ▲]

Detailed reference viewed: 100 (42 ULg)
Full Text
Peer Reviewed
See detailCarrion beetles visiting pig carcasses during early spring in urban, forest and agricultural biotopes of Western Europe
Dekeirsschieter, Jessica ULg; Verheggen, François ULg; Haubruge, Eric ULg et al

in Journal of Insect Science [=JIS] (2011), 11

Carrion beetles are important in terrestrial ecosystems, consuming dead mammals and promoting the recycling of organic matter into ecosystems. Most forensic studies are focused on succession of Diptera ... [more ▼]

Carrion beetles are important in terrestrial ecosystems, consuming dead mammals and promoting the recycling of organic matter into ecosystems. Most forensic studies are focused on succession of Diptera while neglecting Coleoptera. So far, little information is available on carrion beetles postmortem colonization and decomposition process in temperate biogeoclimatic countries. These beetles are however part of the entomofaunal colonization of a dead body. Forensic entomologists need databases concerning the distribution, ecology and phenology of necrophagous insects, including silphids. Forensic entomology uses pig carcasses to surrogate human decomposition and to investigate entomofaunal succession. However, few studies have been conducted in Europe on large carcasses. The work reported here monitored the presence of the carrion beetles (Coleoptera: Silphidae) on decaying pig carcasses in three selected biotopes (forest, crop field, urban site) at the beginning of spring. Seven species of Silphidae were recorded: Nicrophorus humator (Gleditsch), Nicrophorus vespillo (L.), Nicrophorus vespilloides (Herbst), Necrodes littoralis L., Oiceoptoma thoracica L., Thanatophilus sinuatus (Fabricius), Thanatophilus rugosus (L.). All of these species were caught in the forest biotope, and all but O. thoracica were caught in the agricultural biotope. No silphids were caught in the urban site [less ▲]

Detailed reference viewed: 69 (13 ULg)
Peer Reviewed
See detailAttraction of wireworms to root-emitted volatile organic compounds of barley
Barsics, Fanny ULg; Haubruge, Eric ULg; Verheggen, François ULg

Conference (2011, June 20)

The ability of wireworms (Agriotes sordidus Illiger) to orientate towards a blend of volatiles emitted by chopped roots of barley was tested. During individual tests, the larvae chose between the two ... [more ▼]

The ability of wireworms (Agriotes sordidus Illiger) to orientate towards a blend of volatiles emitted by chopped roots of barley was tested. During individual tests, the larvae chose between the two sides of a Y-shaped olfactometer. One side was connected to a chamber containing the chopped roots and the other was connected to an empty chamber. Wireworms chose significantly more often the side of the olfactometer providing the blend of root volatiles. This result underlines the importance of the identification of these compounds and their role assessment alone or combined, as for their effect on wireworms. Such compounds could be used in IPM strategies. [less ▲]

Detailed reference viewed: 18 (3 ULg)
Full Text
Peer Reviewed
See detailMicroorganisms from Aphid Honeydew Attract and Enhance the Efficacy of Natural Enemies
Leroy, Pascal ULg; Sabri, Ahmed ULg; Heuskin, Stéphanie ULg et al

in Nature Communications (2011), 2

Aphids are one of the most serious pests of crops worldwide, causing major yield and economic losses. To control aphids, natural enemies could be an option but their efficacy is sometimes limited by their ... [more ▼]

Aphids are one of the most serious pests of crops worldwide, causing major yield and economic losses. To control aphids, natural enemies could be an option but their efficacy is sometimes limited by their dispersal in natural environment. Here we report the first isolation of a bacterium from the pea aphid Acyrthosiphon pisum honeydew, Staphylococcus sciuri, which acts as a kairomone enhancing the efficiency of aphid natural enemies. Our findings represent the first case of a host-associated bacterium driving prey location and ovipositional preference for the natural enemy. We show that this bacterium has a key role in tritrophic interactions because it is the direct source of volatiles used to locate prey. Some specific semiochemicals produced by S. sciuri were also identified as significant attractants and ovipositional stimulants. The use of this host-associated bacterium could certainly provide a novel approach to control aphids in field and greenhouse systems. [less ▲]

Detailed reference viewed: 149 (68 ULg)
Full Text
See detailAttraction of wireworms to root-emitted volatile organic compounds of barley
Barsics, Fanny ULg; Haubruge, Eric ULg; Verheggen, François ULg

in Ehlers, Ralf-Udo; Crickmore, Neil; Enkerli, Juerg (Eds.) et al Preceedings of the 13th European Meeting "Biological Control in IPM Systems" : Innsbruck (Austria) 19-23 June 2011 (2011, June)

The ability of wireworms (Agriotes sordidus Illiger) to orientate towards a blend of volatiles emitted by chopped roots of barley was tested. During individual tests, the larvae chose between the two ... [more ▼]

The ability of wireworms (Agriotes sordidus Illiger) to orientate towards a blend of volatiles emitted by chopped roots of barley was tested. During individual tests, the larvae chose between the two sides of a Y-shaped olfactometer. One side was connected to a chamber containing the chopped roots and the other was connected to an empty chamber. Wireworms chose significantly more often the side of the olfactometer providing the blend of root volatiles. This result underlines the importance of the identification of these compounds and their role assessment alone or combined, as for their effect on wireworms. Such compounds could be used in IPM strategies. [less ▲]

Detailed reference viewed: 156 (18 ULg)
Peer Reviewed
See detailAnt-aphid mutualism - How do ants locate aphid colonies?
Fischer, Christophe ULg; Sablon, Ludovic ULg; Duriaux, Adrien ULg et al

Poster (2011, June)

That some ant species show mutualistic relationships with some aphid species is well known since several decades. Ants protect aphids against natural enemies and as a reward collect the sugar-rich aphid ... [more ▼]

That some ant species show mutualistic relationships with some aphid species is well known since several decades. Ants protect aphids against natural enemies and as a reward collect the sugar-rich aphid excretion called honeydew. However, very little information is available on possible semiochemicals involved in these interactions. This study aims to identify semiochemicals involved in the establishment of this relation, using both chemical and behavioral approaches. Preliminary choice tests confirmed that ant scouts are able to detect aphid colonies at a distance using volatile organic compounds (VOC). Those VOC influencing ant’s orientation may originate from different sources: the attacked plant, the honeydew produced by the aphids and the aphids themselves. VOC emission profiles of each of those potential sources have been established using gas chromatography. Y-olfactometer assay revealed that honeydew volatile compounds are the key element in this distant attraction. Moreover, based on these VOCs, ant scouts are able to discriminate between the honeydew produced by a myrmecophilous and a non myrmecophilous aphid species. Thus, more than just a sugar source, honeydew is an attractant for ant scouts towards myrmecophilous aphids. [less ▲]

Detailed reference viewed: 77 (9 ULg)
Full Text
See detailVolatile organic compounds of the roots of barley and their role in the rhizosphere
Fiers, Marie ULg; Barsics, Fanny ULg; Camerman, Marc ULg et al

Poster (2011, May 24)

Volatile organic compounds emitted by plants are known to intervene with various biotic environmental factors. Up to now, most of the studies have been focused on aerial volatiles and root liquid exudates ... [more ▼]

Volatile organic compounds emitted by plants are known to intervene with various biotic environmental factors. Up to now, most of the studies have been focused on aerial volatiles and root liquid exudates. Very few researches have been completed concerning belowground volatiles released into the rhizosphere despite their potential capacity to carry information between organisms. The Rhizovol project, started in autumn 2010, involves 5 different units of Gembloux Agro-Bio Tech collectively studying the production of belowground volatiles by barley roots underlying various biotic interactions in the rhizosphere. Some preliminary results of each partner of the project will be presented. To achieve this goal, analytical methods allowing the sampling, separation, identification and quantification of belowground volatile compounds have to be developed, taking into account their potential modifications in the rhizosphere once released by the roots. They enable the subsequent characterization and study of the interactions between barley and its rhizospheric partners chosen for this study. These interactions imply three types of organisms: beneficial organisms, pathogenic agents and plant and insect pests. Beneficial organisms can promote the growth of barley by the emission of volatiles; on the other hand barley can support their growth and metabolism. These phenomenons will be assessed by the study of 19 strains of plant growth-promoting bacteria (PGPR). Three pathogenic agents - two fungi (Fusarium culmorum and Cochliobolus sativus) and one virus (Barley yellow dwarf virus) - were chosen as they are known to cause various diseases on barley, especially on roots. The attractive or repellent effects of barley root volatiles on the pathogenic agents or their vectors, as well as the effect of volatiles on the diseases evolution will be evaluated. The project also includes several types of pests such as plants and insects. Plants can compete with barley for space and nutrients through volatile interactions. This will be assessed by the study of autotoxicity by barley itself and allelopathy with 8 weeds and a hemiparasitic plant (Rhinanthus minor). The effects of barley volatiles can also impact the severity of the attacks by insects. This part will be conducted with wireworms as they represent worldwide known pests, and aphids, through their viral vector role. Eventually, as soil characteristics can strongly influence the diffusion of volatile compounds, the diffusion behaviour of the identified volatile biomolecules through the soil will be modelled. Tritrophic interactions (e.g. insect-plant-pathogenic fungi) will be studied based on each bitrophic interaction results. Over-all, the Rhizovol project aims at improving the knowledge of interactions mediated by volatile compounds in the rhizosphere and at establishing new biocontrol methods that could contribute to integrated disease and pest management systems. [less ▲]

Detailed reference viewed: 40 (7 ULg)
Full Text
Peer Reviewed
See detailImpact of Harmonia axyridis (Coleoptera: Coccinellidae) on the survival rates of other aphidophagous species in semi-field conditions
Vandereycken, Axel ULg; Durieux, Delphine ULg; Joie, Emilie ULg et al

in Communications in Agricultural and Applied Biological Sciences (2011, May 24), 76(2), 219-226

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 ... [more ▼]

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 aphid natural enemies. Interactions between this exotic ladybird and other aphidophagous species present in Belgian agro-ecosystems such as Coccinella septempunctata, Episyrphus balteatus and Chrysoperla carnea are asymmetric to the benefit of H. axyridis. This study focuses on the survival rate of three aphidophagous species Harmonia axyridis (Ha), Coccinella septempunctata (C7) and Episyrphus balteatus (Eb) placed in cages 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. Four types of cages were observed (1) Ha+Eb+C7+ aphids, (2) Ha+Eb+C7, (3) Eb+C7+ aphids and (4) Eb+C7. Each combination was repeated three times. 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, when aphids were present in excess, the survival rates of all aphidophagous insects were lower than in sugar beet probably because A. fabae is less adapted to the potato morphology. Nevertheless, we have observed in potato no mortality of C. 7-punctata during all its development cycle. This suggests that (1) C. 7-punctata may use aphids as food sources more efficiently than H. axyridis and (2) that interactions between aphidophagous could be less frequent (difficulty of mobility). 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. [less ▲]

Detailed reference viewed: 87 (28 ULg)
Full Text
Peer Reviewed
See detailField evaluation of survival rates of Harmonia axyridis (Coleoptera: Coccinellidae) and other aphidophagous species
Vandereycken, Axel ULg; Durieux, Delphine ULg; Joie, Emilie ULg et al

Poster (2011, May 24)

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 ... [more ▼]

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. [less ▲]

Detailed reference viewed: 82 (18 ULg)
Peer Reviewed
See detailAttraction of wireworms to root-emitted volatile organic compounds of barley
Barsics, Fanny ULg; Haubruge, Eric ULg; Verheggen, François ULg

Conference (2011, May 24)

Wireworms, the belowground larvae of click beetles (Coleoptera: Elateridae), represent a threat for various crops, including cereals, potatoes and small fruits, in many countries. In order to promote the ... [more ▼]

Wireworms, the belowground larvae of click beetles (Coleoptera: Elateridae), represent a threat for various crops, including cereals, potatoes and small fruits, in many countries. In order to promote the development of bio-pesticides or the selection of resistant varieties, studies concerning the close relationship between wireworms and the roots they attack have to be conducted. Indeed, lacks of knowledge in the chemical ecology of these small but consequent pests baffle such achievements. Here, we studied the reactions of wireworms (Agriotes sordidus Illiger) facing root-emitted volatile organic compounds (VOCs) of barley. We first tested the ability of wireworms to orientate towards a blend of volatile compounds emitted by seven day’s old mashed roots of barley grown in vermiculite. We used a Y-shaped horizontal olfactometre, which inferior half was filled with compressed and humidified vermiculite. Wireworms were able to detect blends of volatiles emitted by mashed roots, and to orientate their foraging behaviour toward the emission source. Volatile compounds were identified from barley roots using SPME-GC-MS and several chemicals were identified. This study is part of a larger programme which purpose is the identification of VOCs emitted by the roots of barley and different actors of the rhizosphere, and to assess their semiochemical functions. [less ▲]

Detailed reference viewed: 23 (2 ULg)
See detailA semiochemical enhancing the attractiveness of aphidophagous predators in potato crops
Leroy, Pascal ULg; Vandereycken, Axel ULg; Sabri, Ahmed ULg et al

Poster (2011, May 24)

Aphids are major pests of crops worldwide and the use of pesticides has led to resistant populations. The integration of aphid natural enemies in integrated management programs could be an option, but ... [more ▼]

Aphids are major pests of crops worldwide and the use of pesticides has led to resistant populations. The integration of aphid natural enemies in integrated management programs could be an option, but their efficacy is often limited by their quick dispersal from the ecosystem where they are released. Here, using wind-tunnel and field experiments, we have demonstrated that 3-Methyl-2-butenal acts as an efficient attractant and ovipositional stimulant for the hoverfly Episyrphus balteatus (De Geer) (Diptera: Syrphidae), enhancing its efficiency as biological control agent in crop fields. Wind-tunnel assays allowed determining that a minimal dose of 250 µg of 3-Methyl-2-butenal is required to attract the hoverflies over a distance of 2.5 m while a minimal dose of 500 µg is needed to induce the oviposition. Both attraction and oviposition increased proportionally to the tested doses showing that hoverflies are able to regulate their oviposition according to the chemical stimuli from their environment. In field experiments, both Syrphidae and Chrysopidae were strongly attracted by the 3-Methyl-2-butenal at a dose of 10 mg which also induces the oviposition of these two aphid predators in potato crops. This study also highlighted that hoverflies are the most abundant aphid predators found in natural environment. Against aphids, the use of this semiochemical could certainly enhance the efficiency of natural enemies. Furthermore, the use of the chemical cue 3-Methyl-2-butenal could provide a novel approach to control aphids in field and greenhouse systems. [less ▲]

Detailed reference viewed: 63 (20 ULg)