scholarly journals Why stay in a bad relationship? The effect of local host phenology on a generalist butterfly feeding on a low-ranked host

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Hélène Audusseau ◽  
Maria de la Paz Celorio-Mancera ◽  
Niklas Janz ◽  
Sören Nylin
Keyword(s):  
Author(s):  
Florian P. Schiestl ◽  
Erika A. Wallin ◽  
John J. Beck ◽  
Magne Friberg ◽  
John N. Thompson

AbstractVolatiles are of key importance for host-plant recognition in insects. In the pollination system of Lithophragma flowers and Greya moths, moths are highly specialized on Lithophragma, in which they oviposit and thereby pollinate the flowers. Floral volatiles in Lithophragma are highly variable between species and populations, and moths prefer to oviposit into Lithophragma flowers from populations of the local host species. Here we used gas chromatography coupled with electroantennographic detection (GC-EAD) to test whether Greya moths detect specific key volatiles or respond broadly to many volatiles of Lithophragma flowers. We also addressed whether olfactory detection in Greya moths varies across populations, consistent with a co-evolutionary scenario. We analyzed flower volatile samples from three different species and five populations of Lithophragma occurring across a 1400 km range in the Western USA, and their sympatric female Greya politella moths. We showed that Greya politella detect a broad range of Lithophragma volatiles, with a total of 23 compounds being EAD active. We chemically identified 15 of these, including the chiral 6, 10, 14-trimethylpentadecan-2-one (hexahydrofarnesyl acetone), which was not previously detected in Lithophragma. All investigated Lithophragma species produced the (6R, 10R)-enantiomer of this compound. We showed that Greya moths detected not only volatiles of their local Lithophragma plants, but also those from allopatric populations/species that they not encounter in local populations. In conclusion, the generalized detection of volatiles and a lack of co-divergence between volatiles and olfactory detection may be of selective advantage for moths in tracking hosts with rapidly evolving, chemically diverse floral volatiles.


1991 ◽  
Vol 18 (5) ◽  
pp. 427-433 ◽  
Author(s):  
M. GÓMEZ-MORALES ◽  
T. ALVARO ◽  
M. MUÑOZ ◽  
R. GARCIA DEL MORAL ◽  
D. AGUILAR ◽  
...  

2021 ◽  
Author(s):  
Hannelore MacDonald ◽  
Dustin Brisson

Parasite-host interactions can result in periodic population dynamics when parasites over-exploit host populations. The timing of host seasonal activity, or host phenology, determines the frequency and demographic impact of parasite-host interactions which may govern if the parasite can sufficiently over-exploit their hosts to drive population cycles. We describe a mathematical model of a monocyclic, obligate-killer parasite system with seasonal host activity to investigate the consequences of host phenology on host-parasite dynamics. The results suggest that parasites can reach the densities necessary to destabilize host dynamics and drive cycling in only some phenological scenarios, such as environments with short seasons and synchronous host emergence. Further, only parasite lineages that are sufficiently adapted to phenological scenarios with short seasons and synchronous host emergence can achieve the densities necessary to over-exploit hosts and produce population cycles. Host-parasite cycles can also generate an eco-evolutionary feedback that slows parasite adaptation to the phenological environment as rare advantageous phenotypes are driven to extinction when introduced in phases of the cycle where host populations are small and parasite populations are large. The results demonstrate that seasonal environments can drive population cycling in a restricted set of phenological patterns and provides further evidence that the rate of adaptive evolution depends on underlying ecological dynamics.


2004 ◽  
Vol 48 (10) ◽  
pp. 3662-3669 ◽  
Author(s):  
O. Etienne ◽  
C. Picart ◽  
C. Taddei ◽  
Y. Haikel ◽  
J. L. Dimarcq ◽  
...  

ABSTRACT Infection of implanted materials by bacteria constitutes one of the most serious complications following prosthetic surgery. In the present study, we developed a new strategy based on the insertion of an antimicrobial peptide (defensin from Anopheles gambiae mosquitoes) into polyelectrolyte multilayer films built by the alternate deposition of polyanions and polycations. Quartz crystal microbalance and streaming potential measurements were used to follow step by step the construction of the multilayer films and embedding of the defensin within the films. Antimicrobial assays were performed with two strains: Micrococcus luteus (a gram-positive bacterium) and Escherichia coli D22 (a gram-negative bacterium). The inhibition of E. coli D22 growth at the surface of defensin-functionalized films was found to be 98% when 10 antimicrobial peptide layers were inserted in the film architecture. Noticeably, the biofunctionalization could be achieved only when positively charged poly(l-lysine) was the outermost layer of the film. On the basis of the results of bacterial adhesion experiments observed by confocal or electron microscopy, these observations could result from the close interaction of the bacteria with the positively charged ends of the films, which allows defensin to interact with the bacterial membrane structure. These results open new possibilities for the use of such easily built and functionalized architectures onto any type of implantable biomaterial. The modified surfaces are active against microbial infection and represent a novel means of local host protection.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Takashi Yamanoue ◽  
Kentaro Oda ◽  
Koichi Shimozono

A simple application program interface (API) for Java programs running on a wiki is implemented experimentally. A Java program with the API can be running on a wiki, and the Java program can save its data on the wiki. The Java program consists of PukiWiki, which is a popular wiki in Japan, and a plug-in, which starts up Java programs and classes of Java. A Java applet with default access privilege cannot save its data at a local host. We have constructed an API of applets for easy and unified data input and output at a remote host. We also combined the proposed API and the wiki system by introducing a wiki tag for starting Java applets. It is easy to introduce new types of applications using the proposed API. We have embedded programs such as a simple text editor, a simple music editor, a simple drawing program, and programming environments in a PukiWiki system using this API.


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