How to Control Lily Aphids
Bill Inkster
year in late summer. I hesitate to use commercial preparations as there
are fish in the pond. Does anyone have an ingenious method of controlling
these unsightly and havoc-wreaking little pricks? So far I just spray the
pads with a hose, but they return quite rapidly.
Sarah.Santitoro
Try ladybugs (especially their larvae) and lacewings
they're effective AND beneficial.
Maarten van Helden
ink...@unixg.ubc.ca says...
As an entomologist and pond enthousiast I was somewhat surprised. I am not aware
of aphid species feeding on lily pads. Aphid feeding on lily buds might be
found, but I could not find any literature reference there. I've never
seen anything like that on this side of the salt lake, but as you will probably
say: anything is possible in america !!
My guess is that these little crawlers are in fact springtails, small
"primitive" insects (without wings) which live on the water surface (on the
soil, or wherever there are humid spots) and live from detritus (old, decaying
plant parts). They do no harm to the plant !!! It is possible that the aggregate
on lily leaves and other stems. The should not be more then 3-4 mm long, usually
grey or greenish.
Try the following: if you approach a "colony", how do they move away. If they
are springtails they will really jump (up to several cemtimeters), and also move
easily on the water surface using the same method. Aphids cannot jump or walk on
the water, they should fall off ,usually all together using what is called an
alarm pheromone (a gass (volatile) produced when one aphid is disturbed.
If you still don't know try to find an entomologist who can help.
Springtails form large colonies on water with a lot of detritus and a surface
that is not too much disturbed (moving), so usually along the water border
between the stems of plants. Maybe they only move onto your lilies when the
water is movong, e.g. when the fountain is running ???
Better not use chemical control, it might have a lot of adverse effects.
Let me know your conclusions !!!
--
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
||\\ //|| Maarten van Helden
|| \\// || Dept. of Entomology
|| \/ || Wageningen Agricultural University
|||||||||| Binnenhaven 7, 6709 PD
|| || Wageningen, the Netherlands
|| || Tel +31-8370-85118 Fax +31-8370-84821
|| || Email: <maarten....@medew.ento.wau.nl>
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
john suffill
maarten....@medew.ento.wau.nl "Maarten van Helden" writes:
> As an entomologist and pond enthousiast I was somewhat surprised. I am not
> aware
> of aphid species feeding on lily pads. Aphid feeding on lily buds might be
> found, but I could not find any literature reference there. I've never
> seen anything like that on this side of the salt lake, but as you will
> probably say: anything is possible in america !!
Every year I usually have some insect invading the lily-pads. They look
like small black flies, but a quick spray from a hose-pipe (as someone
else pointed out) gets them off the lilies and into the fish. I remember
reading somewhere of an insect that these things will happily make its
home on your lily pads, I just wish I could remember the name and where I
read it....!
[to the original poster]
Are there any frogs/toads in your pond? If not, you could try introducing
them, they should help with your insect problem and add to the local
wildlife as well.
Cheers
--
****************************** Internet: jo...@culloden.demon.co.uk ****
******* John Suffill ******* Fidonet: 2:2502/666.1 ****************
************************** Icenet: 47:343/201.1 ***************
Aaron Hicks
>I seem to get an infestation of aphids (I think) on my lily pads every
>year in late summer. I hesitate to use commercial preparations as there
>are fish in the pond. Does anyone have an ingenious method of controlling
>these unsightly and havoc-wreaking little pricks? So far I just spray the
>pads with a hose, but they return quite rapidly
*snip!!*
Okay, aphids suck. I admit it.
You will have aphids in two places: first off, you will have them
on your lotus- the stems are perfect. They are sheltered from the rain, and
they are protected there. The second place you will find them is on your
water-lillies, usually on the stems.
If your pond is too shallow, and your lillies are very robust growers,
possibly underpotted, the leaves will project above the water, and leave
the very vulnerable stems open to parasitization.
The second thing that may happen is that leaves that are yellowing
and dying off will attract aphids- aphids like yellow, the sign of disease
and death in a plant. This can be used against them: put out a bright yellow
dish, and fill it with water, and add a bit of dishwashing detergent.
*WARNING: do not place the dish such that the contents can ever get
in the pond- either by mischief, malice, or by water spray from rain or
hose or whatever... it will quickly kill fish in your pond!* They will
be attracted to the yellow, crawl in, and the detergent will lower the
surface tension, and they will drown. It will _lower_ numbers, but
never really eliminate them.
The other thing to do (which works with the highly susceptible
water lettuce, as well as the somewhat-susceptible water hyacinth, which
may maintain infestations which become particularly pesky and deep-rooted)
is drown them: put the affected plant underwater. Put the hyacinth or
whatever in a turkey bag, or nylon stocking, or whatever... then weight
it down into the pool: drown for 24 hours, which is overkill. The other
alternative is, if you lillies are FLUSH with the water (no leaves projecting
above), cover them with newspaper: the newspaper will get all soggy and wet,
but hold together for when you remove it in the morning. It will drown all
the aphids if you cover the plant completely! I have tried this only in large
ponds, so I do not know about the toxicity of paper and the inks (which are
supposed to be soy-based, and edible by cattle... but who knows, with
fish gills!). Use it at your peril!
The best option is, if your lillies are in buckets, to simply put
them deeper in the pool- 5-6 feet if necessary. Lower them down in, and then
bring them back up after a day or so: it will not hurt them at all.
Also: the water spray works, but you REALLY have to keep at it.
Every day, 2-3 times a day if you can. Aphids thrive in warm, dry weather
for a reason- they hate water. Further, you have to have aggressive fish:
wimpy, first-year fingerlings from the pet store won't do it. Ravenous,
underfed, aggressive Koi about 4-6" long seem to be best; they will
return to the surface after spraying ends (if they bother to leave), and
will munch down the offending parasites in short order. Above all: keep at
it; aphids are born pregnant, I understand, and are very, very aggressive
animals. Drown them, drown them, drown them.
-AJHicks
NMTech
Dept. of Entropy
Maarten van Helden
>>year in late summer. I hesitate to use commercial preparations as there
>>are fish in the pond. Does anyone have an ingenious method of controlling
>>these unsightly and havoc-wreaking little pricks? So far I just spray the
>
>As an entomologist and pond enthousiast I was somewhat surprised. I am not aware
>of aphid species feeding on lily pads. Aphid feeding on lily buds might be
>found, but I could not find any literature reference there. I've never
>seen anything like that on this side of the salt lake, but as you will probably
>say: anything is possible in america !!
>
>"primitive" insects (without wings) which live on the water surface (on the
>soil, or wherever there are humid spots) and live from detritus (old, decaying
>plant parts). They do no harm to the plant !!! It is possible that the aggregate
>on lily leaves and other stems. The should not be more then 3-4 mm long, usually
>grey or greenish.
>Try the following: if you approach a "colony", how do they move away. If they
>are springtails they will really jump (up to several cemtimeters), and also move
>easily on the water surface using the same method. Aphids cannot jump or walk on
>the water, they should fall off ,usually all together using what is called an
>alarm pheromone (a gass (volatile) produced when one aphid is disturbed.
>If you still don't know try to find an entomologist who can help.
>
>Springtails form large colonies on water with a lot of detritus and a surface
>that is not too much disturbed (moving), so usually along the water border
>between the stems of plants. Maybe they only move onto your lilies when the
>water is movong, e.g. when the fountain is running ???
>
>Better not use chemical control, it might have a lot of adverse effects.
>Let me know your conclusions !!!
>--
A follow up to my own mail: I made a mistake, the insects are probably aphids.
It's the species rhopalosiphum nymphaeae, which lives on water lilies (nymphea spp.)
The little insect is usually dull-green or brownish and is indeed a pest on wtere
lilies, but also on other plants with the same habitus (potamogeton spp, butomus spp
etc) It is a true pest for the growers of water plants. The species overwinters (as
eggs) on prunus trees (plus apple, pear etc) and will invade plants in may and june. The
species is cosmopolitan, so I should have known it !!
I hope some form of bio-control will work. There are several insect species which live
on the surface of ponds which might eat these aphids. How about water striders, have you
ever seen them eating the aphids ???