Search results for "Parasitism"
showing 10 items of 200 documents
Active hiding of social information from information-parasites
2014
Background: Coevolution between pairs of different kind of entities, such as providers and users of information, involves reciprocal selection pressures between them as a consequence of their ecological interaction. Pied flycatchers ( Ficedula hypoleuca ) have been shown to derive fitness benefits (larger clutches) when nesting in proximity to great tits ( Parus major ), presumably because they this way discover and obtain information about nesting sites. Tits suffer from the resulting association (smaller clutches). An arms race between the tits (information host) and the flycatchers (information parasite) could thus result . Great tits often cover eggs with nesting material before, but no…
How to escape from insect egg parasitoids : a review of potential factors explaining parasitoid absence across the Insecta
2020
The egg is the first life stage directly exposed to the environment in oviparous animals, including many vertebrates and most arthropods. Eggs are vulnerable and prone to mortality risks. In arthropods, one of the most common egg mortality factors is attack from parasitoids. Yet, parasitoids that attack the egg stage are absent in more than half of all insect (sub)orders. In this review, we explore possible causes explaining why eggs of some insect taxa are not parasitized. Many insect (sub)orders that are not attacked by egg parasitoids lack herbivorous species, with some notable exceptions. Factors we consider to have led to escape from egg parasitism are parental egg care, rapid egg deve…
An Egg Parasitoid Efficiently Exploits Cues From a Coevolved Host But Not Those From a Novel Host
2019
Egg parasitoids have evolved adaptations to exploit host-associated cues, especially oviposition-induced plant volatiles and odors of gravid females, when foraging for hosts. The entire host selection process is critical for successful parasitism and relevant in defining host specificity of parasitoids. We hypothesized that naïve egg parasitoid females reared on their coevolved host are able to exploit cues related to the coevolved host but not those from a novel host. We used the egg parasitoid Trissolcus japonicus, its coevolved host Halyomorpha halys, and the non-coevolved host Podisus maculiventris to evaluate this hypothesis. H. halys, a polyphagous pest native from Eastern Asia, has i…
Summer time predation on the obligatory off-host stage of an invasive ectoparasite
2016
SUMMARYPredation can regulate populations and strongly affect invasion success of novel prey. The deer ked (Lipoptena cervi; Linnaeus 1758) is an invasive ectoparasite of cervids that spends a long period of its life cycle outside the host. Prior to this study, virtually nothing was known about natural summer time predation on the deer ked. We aimed to evaluate the magnitude of summer time predation onL. cervipupae in different habitats and to identify potential predators. We conducted a set of field experiments, where we exposedL. cervipupae to various ground-dwelling vertebrate and invertebrate predators. The loss of pupae was monitored for different predator guilds. Three habitats of the…
Lobesia botrana larvae develop faster in the presence of parasitoids.
2013
3 pages; International audience; To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-pa…
The joint evolution of the Myxozoa and their alternate hosts: A cnidarian recipe for success and vast biodiversity
2018
The relationships between parasites and their hosts are intimate, dynamic and complex; the evolution of one is inevitably linked to the other. Despite multiple origins of parasitism in the Cnidaria, only parasites belonging to the Myxozoa are characterized by a complex life cycle, alternating between fish and invertebrate hosts, as well as by high species diversity. This inspired us to examine the history of adaptive radiations in myxozoans and their hosts by determining the degree of congruence between their phylogenies and by timing the emergence of myxozoan lineages in relation to their hosts. Recent genomic analyses suggested a common origin of Polypodium hydriforme, a cnidarian parasit…
Iflavirus increases its infectivity and physical stability in association with baculovirus
2016
Virus transmission and the prevalence of infection depend on multiple factors, including the interaction with other viral pathogens infecting the same host. In this study, active replication of an iflavirus, Spodoptera exigua iflavirus 1 (order Picornavirales) was observed in the offspring of insects that survived following inoculation with a pathogenic baculovirus, Spodoptera exigua multiple nucleopolyhedrovirus. Tracking the origin of the iflavirus suggested the association of this virus with the occlusion bodies of the baculovirus. Here we investigated the effect of this association on the stability and infectivity of both viruses. A reduction in baculovirus pathogenicity, without affect…
High food quality increases infection of Gammarus pulex (Crustacea: Amphipoda) by the acanthocephalan parasite Pomphorhynchus laevis.
2019
13 pages; International audience; Parasitism is an important process in ecosystems, but has been largely neglected in ecosystem research. However, parasites are involved in most trophic links in food webs with, in turn, a major role in community structure and ecosystem processes. Several studies have shown that higher nutrient availability in ecosystems tends to increase the prevalence of parasites. Yet, most of these studies focused on resource availability, whereas studies investigating resource quality remain scarce. In this study, we tested the impact of the quality of host food resources on infection by parasites, as well as on the consequences for the host. Three resources were used t…
Unusual multiparasitism causes overweight in a wood mouse,Apodemus sylvaticus(Rodentia: Muridae), from a post-fire regeneration area
2016
Multiparasitism is a common ecological phenomenon, being the norm rather than the exception, in the wild. This article describes the case of a wood mouse, Apodemus sylvaticus, originating from a post-fire regeneration area, infected with multiple helminth species and remarkable overweight. The mouse analyzed was captured at a post-fire regeneration site in the Serra Calderona Natural Park (Comunitat Valenciana, Spain). The rodent was captured and marked for the first time in the spring of 2011, weighing 22.5 g. When it was recaptured in the winter of 2012, it weighed 44.0 g. The mouse was parasitized by a total of 31 helminths belonging to seven species, including six Taenia parva metacesto…
Mucin induces CRISPR-Cas defense in an opportunistic pathogen
2022
It is unknown what circumstances promote particular bacterial defenses against bacterial viruses (phages). Almeida & Hoikkala et al. show that mucin, derived from mucus, greatly accelerates CRISPR-Cas defenses against phage in an opportunistic pathogen. Parasitism by bacteriophages has led to the evolution of a variety of defense mechanisms in their host bacteria. However, it is unclear what factors lead to specific defenses being deployed upon phage infection. To explore this question, we co-evolved the bacterial fish pathogen Flavobacterium columnare and its virulent phage V156 in presence and absence of a eukaryotic host signal (mucin) for sixteen weeks. The presence of mucin leads to a …