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  • Publication
    Métadonnées seulement
    Molecular gut content analysis for detection of intraguild predation by H. axyridis (Coleoptera: Coccinellidae) on non-coccinellid aphidophagous predators
    (2013-3-31)
    Ingels, Brecht
    ;
    ;
    Hautier, Louis
    ;
    Van Leeuwen, Thomas
    ;
    De Clercq, Patrick
    Several studies have demonstrated that the invasive ladybird Harmonia axyridis is a strong intra-guild predator of native species of ladybird. Laboratory studies have shown that H. axyridis can be an intra-guild predator of aphid predators other than coccinellids, including the hoverfly Episyrphus balteatus and lacewing Chrysoperla carnea. However, little is known about the effect of intra-guild predation (IGP) by H. axyridis on hoverfly and lacewing populations in the field. In the present study molecular analyses were used to detect the DNA of E. balteatus and C. carnea in the gut contents of H. axyridis. Primers for the syrphid and chrysopid prey were designed and feeding experiments performed to determine how long prey DNA remains detectable in the guts of this ladybird. DNA detection was influenced by the life stage of the predator and species of prey. Meal size did not affect detection time, except when fourth instar individuals of H. axyridis were fed 10 eggs or one second instar of C. carnea. Predator weight, sex and morpho-type (melanic/non-melanic) did not influence DNA detection. The half-life of the time for which the DNA of the prey remained detectable was calculated for each predator-prey combination, and ranged from 8.9 to 52.4 h. This method can be used to study the ecological importance of IGP by H. axyridis on aphidophagous predators other than coccinellids in the field.
  • Publication
    Métadonnées seulement
    Molecular analysis of the gut contents of Harmonia axyridis (Coleoptera: Coccinellidae) as a method for detecting intra-guild predation by this species on aphidophagous predators other than coccinellids
    (2013)
    Ingels, Brecht
    ;
    ;
    Hautier, Louis
    ;
    Van Leeuwen, T.
    ;
    De Clercq, Patrick
    Several studies have demonstrated that the invasive ladybird Harmonia axyridis is a strong intra-guild predator of native species of ladybird. Laboratory studies have shown that H. axyridis can be an intra-guild predator of aphid predators other than coccinellids, including the hoverfly Episyrphus balteatus and lacewing Chrysoperla carnea. However, little is known about the effect of intra-guild predation (IGP) by H. axyridis on hoverfly and lacewing populations in the field. In the present study molecular analyses were used to detect the DNA of E. balteatus and C. carnea in the gut contents of H. axyridis. Primers for the syrphid and chrysopid prey were designed and feeding experiments performed to determine how long prey DNA remains detectable in the guts of this ladybird. DNA detection was influenced by the life stage of the predator and species of prey. Meal size did not affect detection time, except when fourth instar individuals of H. axyridis were fed 10 eggs or one second instar of C. carnea. Predator weight, sex and morpho-type (melanic/non-melanic) did not influence DNA detection. The half-life of the time for which the DNA of the prey remained detectable was calculated for each predator-prey combination, and ranged from 8.9 to 52.4 h. This method can be used to study the ecological importance of IGP by H. axyridis on aphidophagous predators other than coccinellids in the field.
  • Publication
    Accès libre
    Isolation and characterization of polymorphic microsatellite loci in Acanthoscelides obvelatus Bridwell (Coleoptera: Bruchidae)
    (2003)
    Alvarez, Nadir
    ;
    ;
    Risterucci, A.-M.
    ;
    Hossaert-McKey, Martine
    ;
    Five microsatellite loci were isolated from the bruchid Acanthoscelides obvelatus Bridwell (Coleoptera: Bruchidae). Each locus was polymorphic, with the number of alleles ranging from two to 15. We found high levels of within-population variation at most loci, with heterozygosity ranging from 0.182 to 0.900. Cross-species amplification of these loci was tested in two other species of the genus Acanthoscelides, A. obtectus Say and A. argillaceus Sharp.