title: Asynchrony between Host Plant and Insects-Defoliator within a Tritrophic System: The Role of Herbivore Innate Immunity.
abstract: The effects of asynchrony in the phenology of spring-feeding insect-defoliators and their host plants on insects' fitness, as well as the importance of this effect for the population dynamics of outbreaking species of insects, is a widespread and well-documented phenomenon. However, the spreading of this phenomenon through the food chain, and especially those mechanisms operating this spreading, are still unclear. In this paper, we study the effect of seasonally declined leafquality (estimated in terms of phenolics and nitrogen content) on herbivore fitness, immune parameters and resistance against pathogen by using the silver birch Betula pendula--gypsy moth Lymantria dispar--nucleopolyhedrovirus as the tritrophic system. We show that a phenological mismatch induced by the delay in the emergence of gypsy moth larvae and following feeding on mature leaves has negative effects on the female pupal weight, on the rate of larval development and on the activity of phenoloxidase in the plasma of haemolymph. In addition, the larval susceptibility to exogenous nucleopolyhydrovirus infection as well as covert virus activation were both enhanced due to the phenological mismatch. The observed effects of phenological mismatch on insect-baculovirus interaction may partially explain the strong and fast fluctuations in the population dynamics of the gypsy moth that is often observed in the studied part of the defoliator area. This study also reveals some indirect mechanisms of effect related to host plant quality, which operate through the insect innate immune status and affect resistance to both exogenous and endogenous virus.
authors.affiliation: Laboratory of Insect Pathology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia; Biological Institute, National Research Tomsk State University, Tomsk, Russia.
authors.forename: Vyacheslav V
authors.initials: VV
authors.lastname: Martemyanov
authors.affiliation: Laboratory of Insect Pathology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Pavlushin
authors.affiliation: Laboratory of Insect Pathology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia.
authors.forename: Ivan M
authors.initials: IM
authors.lastname: Dubovskiy
authors.affiliation: Laboratory of Ecological Research and Chromatographic Analysis, Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk, Russia.
authors.forename: Yuliya V
authors.initials: YV
authors.lastname: Yushkova
authors.affiliation: Laboratory of Ecological Research and Chromatographic Analysis, Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk, Russia.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Morosov
authors.affiliation: Laboratory of Ecological Research and Chromatographic Analysis, Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk, Russia.
authors.forename: Elena I
authors.initials: EI
authors.lastname: Chernyak
authors.affiliation: Laboratory of Molecular-Genetic Systems, Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia.
authors.forename: Vadim M
authors.initials: VM
authors.lastname: Efimov
authors.affiliation: Department of Biology, University of Eastern Finland, Joensuu, Finland.
authors.forename: Teija
authors.initials: T
authors.lastname: Ruuhola
authors.affiliation: Laboratory of Insect Pathology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia.
authors.forename: Victor V
authors.initials: VV
authors.lastname: Glupov
mesh_terms: D000818:Animals; D029662:Betula / Q000276:immunology* / Q000469:parasitology*; D060434:Herbivory / Q000502:physiology*; D007814:Larva / Q000502:physiology; D009036:Moths / Q000502:physiology*; D018515:Plant Leaves / Q000276:immunology / Q000469:parasitology