Parasites on trees

[Tony Willis]

Not quite a tree but when I first saw these red growths on a cactus in Chile-Echinopsis chilensis I thought it was the flowers. They are in fact the flowers of a type of mistletoe -Tristerix aphylla which is specific to these plants and is spread by one species of mocking bird

[Lesley Cox]

What a wonderful sight Tony, and a wonderful story too. Red flowers on a cactus, but not its OWN red flowers, and the plant put there by a bird! I hope the mocking bird came back later to appreciate his handy work. Does the mistletoe just sit there as an attractive guest or does it actually harm the cactus host?

[Paul T]

Trade you Paul. One cane toad (male) for 20,000 possums. We can be generous too.

 

I would imagine that the mistletoe on the Cactus would be feeding from the cactus itself, rather than just using it for support?  Quite striking though, aren't they?

[Anthony Darby]

I would imagine that the mistletoe on the Cactus would be feeding from the cactus itself, rather than just using it for support?  Quite striking though, aren't they?

Quite right Paul - a parasite, unlike caterpillars.

[Stephenb]

Fantastic picture, never heard of that one before. I was lucky enough to see the New Zealand Red Misteltoe in South Island, thinking it was the tree (the forest was red with flowering Metrosideros spp)

http://upload.wikimedia.org/wikipedia/en/d/d7/DSCN5417-red-mistletoe_rebal_b.jpg

I think I also remember that the misteltoe was under threat from those possums....

[Paul T]

Wow, what a picture Stephen. 

[Stephenb]

Not mine, unfortunately, but yes...

[Tony Willis]

What a wonderful sight Tony, and a wonderful story too. Red flowers on a cactus, but not its OWN red flowers, and the plant put there by a bird! I hope the mocking bird came back later to appreciate his handy work. Does the mistletoe just sit there as an attractive guest or does it actually harm the cactus host?

Stephen a wonderful picture.

Lesley research has shown that the mistletoe has a significant harmful effect on the cactus. It does not photosynthesise and is totally dependent on its host.It greatly reduces its flowering and therefore fruiting capability

[Lesley Cox]

That's a shame that the cactus is harmed. It seems illogical to me that a parasite will often kill the host on which it depends. So it is too, with fishing fleets which deplete the stocks so much that they are all but extinct. Then what? Won't go into the question of whaling. This isn't a polital Forum, but.....

In a good year, the South Island Metrosideros forests are rich crimson with their flowers and the mistletoe adds but is in tiny quantities, compared with the flowers of the Rata.

[David Lyttle]

Fantastic picture, never heard of that one before. I was lucky enough to see the New Zealand Red Misteltoe in South Island, thinking it was the tree (the forest was red with flowering Metrosideros spp)

I think I also remember that the misteltoe was under threat from those possums....

The mistletoes are under severe threat from possums so much so that our Department of Conservation nails metal sleeves around trees to protect them. Here are some pictures: the host is Nothofagus

[ruweiss]

Good news from the poor trees:
The infested trees now begin to recover and start with new leaves.
At the ground around them are many of the moths, only the trunks seem
to wear white stockings.