Subject: Re: vectors

Still, does the mite die from or are they effected by the virus or are  
they
immune? That would be more in keeping with a disease vector.

Bill,

   I have speculated that perhaps what we really need to breed  in  
bees is mite tolerance  & resistance to virus infection/disease.

  The way that diseases, virus, are vectored by insects to other  
animals or plants can be very complex.  Simply put the virus can  
either be physically moved from point a to b or the virus may infect  
(at some level) the vector and undergoing changes before returning to  
the host.   Virus can be taken up by the vector and and pass through  
the gut where the  particles move through the insect (or mite)  
hemolymph and can then be sequestered in a gland.  At this point the  
virus could undergo changes during multiplication.  Then it reinfects  
the host on the next feed along with a glandular exudate.  Think the  
salivary exudate injected during a mosquito bite to reduce coagulation  
& prevent the host from feeling a bite.

The virus in this later case may get vector genetics to help it  
survive/multiply in the vector without being acted on by the immune  
system .  These changes could either reduce or increase the effect on  
the target host.

As for definitions.  The best known & therefor most used examples are  
human borne diseases from mosquitos or flies.  When you delve into  
virology of insects, bacteria, plants it becomes a very specialized  
field with less well known classes of virus & virus life cycles less  
well elucidated.  There are some general trends but some really weird  
stuff hapens in the virus world.

Defining life cycles of virus is very tedious, mostly because virus  
particles are so small.  I remember a plant virology course & lab that  
taught me that I did not want to be a virologist!

Anyone know of  a virologist working on the life cycle of these  
virus?  IAPV?  Working with virus in mites?

Additionally,  I have not heard much on the negative impact of the  
salivary gland exudates from the mites causing immune system crash in  
bees.  As the mites feed they spit up an exudate that assists their  
feeding--this apparently allows otherwise non-infective microbes a  
chance to against the host immune system and thereby causing  
infections that ordinarily would not happen.

Mike

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