A really complex interaction between plant host, fungus, moth, and parasitoid

[Michael Gochfeld]

As I understand the following article:

The plant Silene is a favored food item for a moth  Hadena.
The moth caterpillars are parasitized by a specialist parasitoid  Microplitis.
The moth caterpillars hide from the wasp in the seed capsules where they eat the seeds.
The fungus reduces the number of seed capsules so there is less food and the wasps are more successful in hitting the moths.
Therefore the adult female moth prefers to lay on Silene plants that don't have the fungus.  Not a surprise really, but...
How do the moths know this?
Does the fungus care whether the moth is successful or not?

A really neat system.  MIKE GOCHFELD

Neal Smith wrote:

>  Once you read it twice, you will get comfortable with the concept of "Enemy-Free Space"!!!!!!!!!!!!!!
>  It has some nice color photos to guide you through this non-simple interaction!!!!!!!!!!!!!!!!!
>
>  A plant pathogen reduces the enemy-free space of an insect herbivore on a shared host plant
>  Arjen Biere ; Jelmer A. Elzinga ; Sonja C. Honders ; Jeffrey A. Harvey
>  Proceedings The Royal Society Biological Sciences      Volume: 269 Number: 1506 Page: 2197 -- 2204
>
>
> Abstract: An important mechanism in stabilizing tightly linked host-parasitoid and prey-predator interactions is the presence of refuges that protect organisms from their natural enemies. However, the presence and quality of refuges can be strongly affected by the environment. We show that infection of the host plant Silene latifolia by its specialist fungal plant pathogen Microbotryum violaceum dramatically alters the enemy-free space of a herbivore, the specialist noctuid seed predator Hadena bicruris, on their shared host plant. The pathogen arrests the development of seed capsules that serve as refuges for the herbivore's offspring against the specialist parasitoid Microplitis tristis, a major source of mortality of H. bicruris in the field. Pathogen infection resulted both in lower host-plant food quality, causing reduced adult emergence, and in twofold higher rates of parasitism of the herbivore. We interpret the strong oviposition preference of H. bicruris for uninfected
> plants in the field as an adaptive response, positioning offspring on refuge-rich, high-quality hosts. To our knowledge, this is the first demonstration that plant-inhabiting micro-organisms can affect higher trophic interactions through alteration of host refuge quality. We speculate that such interference can potentially destabilize tightly linked multitrophic interactions.
>
>
>
>   ------------------------------------------------------------------------
>                           Name: enemy-freespace.pdf
>    enemy-freespace.pdf    Type: Portable Document Format (application/pdf)
>                       Encoding: base64


 
 ------------------------------------------------------------ 

   For subscription and related information about LEPS-L visit:

   http://www.peabody.yale.edu/other/lepsl