Search results for " defence"
showing 5 items of 415 documents
Can warning signals be honest? : wing colouration and the strength of chemical defence in the female wood tiger moth (Parasemia plataginis)
2016
The warning displays of aposematic organisms signal to predators that they possess a secondary defence and are unprofitable. Within species variation exists in the strength of the signal and defence. As natural selection is expected to favour higher levels of defence, variation in such traits requires explanation. One hypothesis is that the strength of primary and secondary defences are correlated as they reflect the condition of the signaller. This study explores if variation in individual conspicuousness is an honest signal of the level of defence in the wood tiger moth (Parasemia plantaginis). P. plantaginis has conspicuous hind wing warning colouration, which in females varies from yell…
Influence of colour, smell and taste on the survival of the wood tiger moth (Arctia plantaginis) adults during predation event
2021
Saalistajien torjumiseksi saalis voi käyttää erilaisia puolustusmekanismeja, jotka stimuloivat useita eri aisteja (ts. multimodaalista signalointia). Esimerkiksi aposemaattiset eliöt puolustautuvat varoitussignaalin lisäksi sekundaarisella puolustuksella. Tässä tutkimuksessa keskityttiin siihen, kuinka täpläsiilikkään (Arctia plantaginis) väritys (genotyypit WW, Wy ovat valkoisia ja yy keltaisia), haju (metoksipyratsiinista) ja maku (pyrrolitsidiinialkaloidista) toimivat puolustuksena lintusaalistajien hyökkäyksiä vastaan. Linnuille tarjottiin kummankin värisiä eläviä siilikkäitä, joita oli manipuloitu niin, että niillä oli joko hajua, makua tai molempia näistä. Näin pystyttiin tutkimaan ku…
Complex plant quality—microbiota–population interactions modulate the response of a specialist herbivore to the defence of its host plant
2022
Many specialist herbivores have evolved strategies to cope with plant defences, with gut microbiota potentially participating to such adaptations. In this study, we assessed whether the history of plant use (population origin) and microbiota may interact with plant defence adaptation. We tested whether microbiota enhance the performance of Melitaea cinxia larvae on their host plant, Plantago lanceolata and increase their ability to cope the defensive compounds, iridoid glycosides (IGs). The gut microbiota were significantly affected by both larval population origin and host plant IG level. Contrary to our prediction, impoverishing the microbiota with antibiotic treatment did not reduce larv…
Multimodal Aposematic Signals and Their Emerging Role in Mate Attraction
2018
Chemically defended animals often display conspicuous color patterns that predators learn to associate with their unprofitability and subsequently avoid. Such animals (i.e., aposematic), deter predators by stimulating their visual and chemical sensory channels. Hence, aposematism is considered to be “multimodal.” The evolution of warning signals (and to a lesser degree their accompanying chemical defenses) is fundamentally linked to natural selection by predators. Lately, however, increasing evidence also points to a role of sexual selection shaping warning signal evolution. One of the species in which this has been shown is the wood tiger moth, Arctia plantaginis, which we here put forward…
Analysis of the Potential of an Increase in Yeast Output Resulting from the Application of Additional Process Wastewater in the Evaporator Station
2019
This paper reports the results of an analysis of process wastewater streams in the context of an increase in yeast production. This research is based on the analysis of data from the biggest yeast factory in Europe. The research presented in this paper involves the analysis of the influence of direction of additional wastewater into the evaporator station on yeast production. In the process wastewater, nitrogen is mainly present in organic forms. The analysis reported in this paper involves the concentration of total nitrogen in wastewater streams, as it is the main parameter applied to determine the amount of wastewater that can be applied in agricultural fields. Directing additional waste…