Can daisies kill tadpoles?

The Frog Watch project focuses on frog-friendly gardening - the approach to conservation is based on learning, appreciation and involvement. This forum deals with all topics relating to providing habitat for local frogs including ponds, plants, and fish.

Moderators: Chris Key, Gerry Marantelli, Mod Squad

alvallis
tadpole
tadpole
Posts: 14
Joined: Sun Jan 18, 2009 11:16 am
Location: Thornleigh, Sydney, NSW

Can daisies kill tadpoles?

Postby alvallis » Tue Jan 22, 2013 9:16 am

I've had four egg masses this summer and it seems only a small proportion of tadpoles have survived. I can't figure out why, last year, with five egg masses, I had seemingly millions of taddies. I have daisies growing at the edge of the pond and hanging over the edge to give the frogs a place to mate (under the overhanging daisy plant) which they do. But now I'm wondering if there is something in the daisies which is toxic to taddies.

I've searched online but can't find any reference to it. Does anyone else have overhanging daisies and normal survival of tadpoles?
Attachments
DSCF1813 [640x480] [640x480].jpg
This is the pond and the daisies around it

Who
tadpole
tadpole
Posts: 22
Joined: Sat Dec 01, 2012 3:41 pm

Postby Who » Tue Jan 22, 2013 4:04 pm

Pyrethrin (a neurotoxin) comes from the Pyrethrum daisy (Tanacetum cinerariaefolium), some other daisies also produce pyrethrin, but in lesser quantities.

So, it's possible that the dasies could be to blame.

alvallis
tadpole
tadpole
Posts: 14
Joined: Sun Jan 18, 2009 11:16 am
Location: Thornleigh, Sydney, NSW

I think you might be right :(

Postby alvallis » Tue Jan 22, 2013 6:55 pm

I've got a horrible feeling you're right and I've been poisoning them. How ghastly. Funny though that the dragonfly larvae are thriving and they actually are insects. I do seem to have more dragonfly larvae than usual but I still don't believe they could have polished off that many tadpoles. Looks like I'll have to rip out the daisies and find replacements.
Darn it.
Thanks very much for this idea.

Sean
frog
frog
Posts: 183
Joined: Thu Jan 13, 2011 11:38 am

Postby Sean » Tue Jan 22, 2013 10:05 pm

Maybe another possibility could be oxygen depletion? See the last post by Nick Thorne on this page:

http://frogs.org.au/community/viewtopic ... b4a93d2aa1

Who
tadpole
tadpole
Posts: 22
Joined: Sat Dec 01, 2012 3:41 pm

Postby Who » Tue Jan 22, 2013 10:56 pm

I was just responding with a possible link between the daisies and the pond problem, but Sean is correct, in that it could (perhaps even more likely) be something else, so no need to rip the daisies out at this point, they might not even be a pyrethrin producing species. You could trim the overhanging bit's if you like, pyrethrin comes from the flower seeds, not the leaves.

One other 'out there' posibillity, a contaminant brought in by a visiting waterbird (especially if there's salt water nearby), though I'm not sure they would be attracted to a small pond.

alvallis
tadpole
tadpole
Posts: 14
Joined: Sun Jan 18, 2009 11:16 am
Location: Thornleigh, Sydney, NSW

Postby alvallis » Wed Jan 23, 2013 7:16 pm

Yeah, that could well be right, about the oxygen depletion. We have had a lot of overcast weather. Hopefully next summer I'll have better luck.
Thanks for all your help :)

Sean
frog
frog
Posts: 183
Joined: Thu Jan 13, 2011 11:38 am

Postby Sean » Thu Jan 24, 2013 12:56 pm

You might just need a small pump or air stone if you don't have one already? :)

alvallis
tadpole
tadpole
Posts: 14
Joined: Sun Jan 18, 2009 11:16 am
Location: Thornleigh, Sydney, NSW

Postby alvallis » Thu Jan 24, 2013 6:08 pm

Thanks Sean. I'd rather not go there. I don't want to have to run a lead to the pond. And I've never had a problem before so I think I'll just wait for next summer and see what happens.


Return to “Frog-friendly gardening”

Who is online

Users browsing this forum: No registered users and 1 guest