On Wed, 17 Nov 1999 22:33:31 -0800, "Russell Farris"
<tryggvi at email.msn.com> wrote:
>I know there are viruses that prey on bacteria. Chlamydiae have been found
>in protozoans. Are there other examples of pathogens having pathogens. Are
>there, for example, bacteria that attack helminth worms? Thanks.
If we move outside the classical parasites there are numerous examples
from the parasitoid wasps, where 'hyperparasitism' is a common
phenomenon. This is the situation where one species of parasitoid wasp
lays an egg in a host (say a caterpillar) and then another species
comes along and oviposits in the same host, killing the initial
parasitoid and taking the host over. Im not sure how many of these
just use the same host once its already parasitised and how many
actually develop in the body of the first parasitoid, but I'm sure
that some do.