Immune response of nun moth (Lymantria monacha) larvae after parasitism by endoparasitic wasps
Abstract
Parasitic wasps (parasitoids) are important natural enemies of caterpillars. They have a high potential in regulating the population dynamics of their host species. For many years we have been working with the model system gypsy moth (Lymantria dispar) and two important natural enemies Glyptapanteles liparidis, a gregarious braconid wasp, and the solitary wasp species Glyptapanteles porthetriae. As larvae the wasps develop in growing, molting caterpillars. In the proposed study we use two species of larval endoparasitoids to evaluate their potential role as natural enemies for nun moth (Lymantria monacha), a major pest of coniferous stands in Europe. Physiological, biochemical, and molecular biology approaches will be applied to study how the wasp manipulates the immune system of the host in favor of its progeny. We try to characterize some of the viral genes that are involved in immunosuppression and analyze their upregulation or suppression in the parasitized host. Our model system serves as an excellent tool in order to study the physiological dynamics of host-parasitoid relationships. Parasitization initiates many immunological and endocrine events in the host which facilitate parasitism and ensure successful development of the wasp’s progeny. The female wasp injects a large double-stranded DNA virus (polydnavirus, PDV) into the host during oviposition, and the virus triggers the onset of immunosuppression in the host. Host juvenile hormone titers remain high throughout parasitism, instead of declining as occurs in unparasitized, premetamorphic larvae, and the hosts are developmentally arrested as larvae. Parasitized larvae cease feeding before their parasitoids emerge, and this behavior is maintained until the host larva dies. Because PDV genes play important regulatory roles in compromising host immunity and in causing host developmental arrest, these genes offer opportunities for increasing the virulence of insect pathogens (e.g. baculoviruses) in both natural and unnatural hosts. The identification, characterization, and determination of the mode of action of these genes are prerequisites for the development of new, cost-efficient and environmentally safe pest control agents.
Lymantria monacha Glyptapanteles liparidis Glyptapanteles porthetriae parasitic wasps immune response
Publikationen
Host defenses and parasitoid success: Glyptapanteles liparidis parasitism of permissive and refractory host species
Autoren: Schafellner, C; Schopf, A Jahr: 2011
Conference & Workshop proceedings, paper, abstract
PDV of Glyptapanteles liparidis: Effects on development and immunity in permissive and refractory host larvae
Autoren: Schafellner, C; Schopf A. Jahr: 2011
Conference & Workshop proceedings, paper, abstract
The role of polydnaviruses in modulating host immunity and development p. 109. [L]
Autoren: Schafellner, C; Schopf, A Jahr: 2011
Conference & Workshop proceedings, paper, abstract
Comparison of the development of nun moth (Lymantria monacha) and gypsy moth (Lymantria dispar) on semi-artificial diets
Autoren: Markóné-Nagy, K; Schafellner, C Jahr: 2011
Conference & Workshop proceedings, paper, abstract
Parasitische Wespen und ihre viralen Helfer
Autoren: Schafellner, C; Schopf, A Jahr: 2010
Journal articles
Permissive and non-permissive hosts: PDV as key factor for parasitoid success?
Autoren: Schafellner, C; Schopf, A Jahr: 2010
Conference & Workshop proceedings, paper, abstract
Host immune response induced by the endoparasitic wasp Glyptapanteles liparidis
Autoren: Schafellner, C; Schopf, A Jahr: 2009
Conference & Workshop proceedings, paper, abstract
Project staff
Christa Schafellner
Priv.-Doz. Dr.phil. Christa Schafellner
christa.schafellner@boku.ac.at
Tel: +43 1 47654-91619
Project Leader
01.09.2010 - 31.12.2016