Search results for "Plantago"
showing 10 items of 18 documents
Differential performance of a specialist and two generalist herbivores and their parasitoids on Plantago lanceolata
2011
The ability to cope with plant defense chemicals differs between specialist and generalist species. In this study, we examined the effects of the concentration of the two main iridoid glycosides (IGs) in Plantago lanceolata, aucubin and catalpol, on the performance of a specialist and two generalist herbivores and their respective endoparasitoids. Development of the specialist herbivore Melitaea cinxia was unaffected by the total leaf IG concentration in its host plant. By contrast, the generalist herbivores Spodoptera exigua and Chrysodeixis chalcites showed delayed larval and pupal development on plant genotypes with high leaf IG concentrations, respectively. This result is in line with t…
The roles of foraging environment, host species, and host diet for a generalist pupal parasitoid
2018
Interactive effects between diet and genotypes of host and pathogen define the severity of infection
2012
Host resistance and parasite virulence are influenced by multiple interacting factors in complex natural communities. Yet, these interactive effects are seldom studied concurrently, resulting in poor understanding of host-pathogen-environment dynamics. Here, we investigated how the level of opportunist pathogen virulence, strength of host immunity and the host condition manipulated via diet affect the survival of wood tiger moth Parasemia plantaginis (Arctidae). Larvae from “low cuticular melanin” and “high cuticular melanin” (considered as low and high pathogen resistance, respectively) selection lines were infected with moderately and highly virulent bacteria strains of Serratia marcescen…
Oviposition Cues for a Specialist Butterfly–Plant Chemistry and Size
2008
The oviposition choice of an insect herbivore is based on a complex set of stimuli and responses. In this study, we examined the effect of plant secondary chemistry (the iridoid glycosides aucubin and catalpol) and aspects of size of the plant Plantago lanceolata, on the oviposition behavior of the specialist butterfly Melitaea cinxia. Iridoid glycosides are known to deter feeding or decrease the growth rate of generalist insect herbivores, but can act as oviposition cues and feeding stimulants for specialized herbivores. In a previous observational study of M. cinxia in the field, oviposition was associated with high levels of aucubin. However, this association could have been the cause (b…
Spatiotemporal Structure of Host‐Pathogen Interactions in a Metapopulation
2009
International audience; The ecological and evolutionary dynamics of species are influenced by spatiotemporal variation in population size. Unfortunately, we are usually limited in our ability to investigate the numerical dynamics of natural populations across large spatial scales and over long periods of time. Here we combine mechanistic and statistical approaches to reconstruct continuous-time infection dynamics of an obligate fungal pathogen on the basis of discrete-time occurrence data. The pathogen, Podosphaera plantaginis, infects its host plant, Plantago lanceolata, in a metapopulation setting where the presence of the pathogen has been recorded annually for 6 years in similar to 4,00…
Nonchemical weeding of medicinal and aromatic plants
2013
International audience; Medicinal and aromatic plants are major crops of domestic and industrial interest. Medicinal and aromatic plants are increasingly organically grown to enhance profitability. However, the presence of weeds may lead to a decrease in both yield and quality. Therefore, nonchemical methods of weed control are needed. In this study, mechanical weeding, flaming, stale seedbed, and biodegradable mulch were tested from 2003/2004 to 2006/2007 on coriander, fennel, and psyllium. Biomass and seed yield were measured. The biomass of weeds remaining at harvest was also measured. Results show a high sensitivity of coriander, fennel, and psyllium crops to the presence of weeds. Stal…
Herbicidal potential of aqueous extracts from Melia azedarach L., Artemisia arborescens L., Rhus coriaria L. and Lantana camara L.
2017
In the search for new strategies for weed management in agricultural systems, a great interest is to use the plant extracts to replace or integrate, chemical weed control. Two experiments were done to test the effects of plant water extracts from Chinaberry (Melia azedarach L.), Tree Wormwood (Artemisia arborescens (Vaill.) L.), Sicilian Sumac (Rhus coriaria L.) and Lantana (Lantana camara L.) on seed germination of Rocket (Eruca sativa Mill.), Rapeseed (Brassica napus L.), Bladderflower (Araujia sericifera Brot.) and Psyllium (Plantago psyllium L). The water extracts (pure and 50% mixtures) from the donor species were applied on seeds of recipient plants. In second experiment in pots, thes…
Diurnal Variation of Non-Arboreal Pollen in the Air in Finland
1981
Abstract This study was carried out in Jyvaskyla and Turku, in central and southern Finland, with Burkard spore traps. The average diurnal variation of all non-arboreal pollen types found in sufficient quantities is presented. A high concentration of Artemisia pollen lasting 4–8 hours was found mainly in the morning. The highest concentrations of Brassicaceae, Calluna, Cyperaceae and Rosaceae occurred during the daylight hours, often with no definite peaks. The peak occurrence of Chenopodiaceae, Compositae and Plantago pollen was around 12.00 and of Rumex from 06.00 to 10.00. The diurnal variation of Poaceae pollen varies considerably depending on the species flowering at the time. Peaks oc…
Arbuscular mycorrhizal fungi influence host infection during epidemics in a wild plant pathosystem
2022
SummaryWhile pathogenic and mutualistic microbes are ubiquitous across ecosystems and often co-occur within hosts, how they interact to determine patterns of disease in genetically diverse wild populations is unknown.To test whether microbial mutualists provide protection against pathogens, and whether this varies among host genotypes, we conducted a field experiment in three naturally-occurring epidemics of a fungal pathogen, Podosphaera plantaginis, infecting a host plant, Plantago lanceolata, in the Åland Islands, Finland. In each population, we collected epidemiological data on experimental plants from six allopatric populations that had been inoculated with a mixture of mutualistic arb…