Safe mozzie killer to add to water

[Agamemnon]

I am growing a Dicksonia antarctica tree fern and have it in a 30cm pot. A biologist friend of mine suggested standing the pot in a shallow container of water to promote growth and maintain humidity.

I've done this but am a little worried about mosquito larvae and the attendent problems of dengue/ross river fever especially this time of year in the tropics. I was just wondering if anyone knew of something organic I can add to the shallow water container that will kill any mozzie larvae but not kill the fern???

[Happy Cadaver]

I heard about Splianthes being used to kill mosquito larvae, Spilantol is sposed to be a good insecticide. I tried it and it didn't seem to work.

Tobacco leaves, perhaps chilli?

Oil on the water surface should work, try an extra virgin olive oil, organic

[Agamemnon]

Oil on the water surface should work, try an extra virgin olive oil, organic

Thanxs Darcy, I reckon olive oil should do the trick!

[Happy Cadaver]

you may have to change the oil once a fortnight or earlier if it goes a bit rank, remember to make it thick enough so the larvae can't stick their nose through to breathe.

A more simple trick I thought of would be just to change the water every week, get the larvae just before they take off

[Darklight]

A more simple trick I thought of would be just to change the water every week, get the larvae just before they take off

I was told years ago that kero would also work for water tanks, might work here. It'll float nicely and won't mix with the water. Make sure you keep it well above drain hole level tho, wouldn't want any getting to the plant

[foolsbreath]

Cinnamon oil my friend, or for that mater a small amount of cinnamon. The cinnamaldehde works a treat, better that DEET,

Larvicidal activity is judged with a measurement called LC50. “The LC50 value is the concentration that kills 50 percent of mosquito larvae in 24 hours

Out of four essential oils, Cinnamaldehyde, cinnamyl acetate, eugenol and anethole, Cinnamaldehyde exhibited the strongest activity against mosquitos with an LC50 of 29 ppm, 29mg of cinnamaldehyde per litre of water. Cinnamon oil (Cassia) is 80% cinnamaldehyde!!

[Torsten]

I have Cinnamon (Cassia) oil here. If there is demand I am happy to list it in the shop.

[foolsbreath]

I'd be keen for some, just add a bit to the rain water tank, mossies are terrible this year!

[Agamemnon]

Cinnamon/ oil sounds like a great way to go to make a mozzie miserable!

[Benzito]

Obviously this is of no help in a 'shallow container of water', but if you are talking large bodies of water like dams or bathtubs, etc, fish are the best thing for getting rid of mosquito larvae.

Goldfish will work, but they also eat frogspawn and tadpoles.

If you're worried about frogs, try 'mountain clouds' or 'mountain minnows', as they are commonly known.

Or if you want a native alternative, get 'pacific blue eyes', they will leave frogspawn alone aswell.

The mountain clouds can survive cold water, the blue eyes need sub-tropical conditions.

And remember, I said the 'blue eyes' are native, but that doesn't mean they are native to your area. You could still be introducing a pest...

[Ed Dunkel]

Aquatic free floating Utricularia species like U. gibba could be considered.

This is an aquatic carnivourous plant (floats around near the surface) that has little bladders with triggers.

Mozzy larvea (or other small insects) set off the triggers and get sucked into the bladders for digestion.

They do require quite a bit of sunlight but a shallow tray which is continously wet is perfect for them. I'm also not to sure how effective they are in controlling larvea. I would guess if they grow well and cover the surface thickly, they would probably capture the majority of them.

Again, this can also be considered a weedy species to some parts of Australia.

I have some growing in my pond, if anyone is interested I could pull some out. They propagate easily (hence the weediness)Aquatic

[Entheo]

Aquatic free floating Utricularia species like U. gibba could be considered.

Again, this can also be considered a weedy species to some parts of Australia.

Dont know why you'ld consider weedy Utricularia as a problem, as there are many species of Bladderworts/Fairy Aprons that are native, and weedy (vigourous growth) would be great for controlling mozzies.

and here's a locality map of Utricularia gibba

[Ed Dunkel]

Dont know why you'ld consider weedy Utricularia as a problem, as there are many species of Bladderworts/Fairy Aprons that are native, and weedy (vigourous growth) would be great for controlling mozzies.

and here's a locality map of Utricularia gibba

Could you repost the map, I'm interested in where they are distributed, the only distribution i found was in WA. Hence my weedyness statement.

My definition of Weedy meaning, any plant that is not found in its natural environment.

This normally means it doesn't have a natural system in place to keep a check on its reproduction/growth etc.. Thus it potentially disrups the balance of the new ecosystem is has moved into.

It's something to be aware about to some extent.

In a bucket with a treefern to control mozzies would be a great thing. In a waterway system, pushing out indigenous vegetation and animals, potentially disasterous.

[Entheo]

Could you repost the map, I'm interested in where they are distributed, the only distribution i found was in WA. Hence my weedyness statement.

My definition of Weedy meaning, any plant that is not found in its natural environment.

here's a map from Calm of all WA Utricularia

Utricularia species from WA (quite a few)

http://tinyurl.com/9wjh8

and reposting the map of U. gibba (Im using photobucket now

and on Weedy, would you consider something weedy if it was native but its predator/s had been eliminated, allowing vigourous growth? Or some other change in the environment that allowed rapid growth such as increased nutrients etc.

[Ed Dunkel]

and on Weedy, would you consider something weedy if it was native but its predator/s had been eliminated, allowing vigourous growth? Or some other change in the environment that allowed rapid growth such as increased nutrients etc.

Cheers for the maps.

I think if it's predators had been eliminated it would most likely exhibit weedy growth characteristics and to some definition of 'weediness' it would probably considered weedy. Nutrient would probably also show this in some cases.

I was more concerned with "introduced weedyness" This could be as simple as introducing a native species across a narrow geographical barrier (for that species) and introducing it to the new environment.

Personally, I don't think this would always be such a large issue as the chance of this happening for some species could be quite reasonable (that they cross the geographical barrier with the help of some migratory animal that can cross the geographical barrier, i.e. seeds caught in the fur or travelling in the bowels, ice age allowing species to cross seas with lowering ocean levels etc..)

But human 'ignorance/stupididty' is way to efficient to help this process along at a much faster rate, this could case potential devistations and inbalances in estabished ecosystems.

(This rambling is not bases on thourough study in the field of ecosystems and introduced species so I expect a flogging arriving from a random corner any moment now ;))

The issue is also made more difficult by the definition of weedyness being quite different depending on who interprets it and from what field they come from. It's a complex issue I guess.

Example of U. gibba weediness:

Utricularia gibba L.: a New Bladderwort Record for Victoria

John Eichler

Abstract

This article records Utricularia gibba from two sites in the Frankston area, discusses the status of the plant in Victoria and suggests that it has the potential to become an environmental weed.

(The Victorian Naturalist 117 (2), 2000, 66-67.)

http://home.vicnet.net.au/~fncv/vicnat/117_2.htm#Abstract6