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  Amorph Blues
From: Neil Gordon <neil at ng23.abelgratis.co.uk> on 2004.07.03 at 19:03:46(11709)
Posted this a couple of days ago, but it didnt appear to get posted, so
here it is again.....
...apologies if you got it already.

Ok, after recieving two Amorphs from Wilberts yearly distribution, i've
been eagerly awaiting a bud to appear.
Every couple of weeks, ive been gently brushing aside the soil to see
if anythings happening.
Now, the A. Declinatus was only a very tiny corm less than 1cm across,
and started to make a pointy little bud shape not long after i recieved
it, (maybe a couple of weeks) and then stopped. Ok, was still firm, and
a good colour - up until today that is, when i decided to check again
as all of my other Amorphs are now either well into bud or nearly in
full leaf.

So i brushed the soil aside, found the corm, still same size
(obviously!) still with the tiny bud shape on top, but to my dismay,
was squishy when held.
So i broke it in half and what was inside? One of these little buggers.
http://www.ng23.abelgratis.co.uk/bug/damn_bug.jpg
It was (past tense intended!) about 5mm long.

Does anyone recognise what it may be? Is it contagious? Should I spray
the soil of my other amorphs with insecticide?

Fortunately the A konkanensis i also recieved is now starting to bud,
but the Declinatus was, of the 2, the one I realy wanted. Isnt that
always the way.

ANY help apreciated. Thanks in advance.

Neil

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From: Dan Levin <levin at pixar.com> on 2004.07.04 at 09:38:40(11711)
Neil-

I knew exactly what pest you'd found even before I clicked on
the link to view your image. Sadly, I find these all too often in
the rotting tubers/ corms of many aroids; Amorphophallus and
Alocasia especially. The pest you discovered is the larval or maggot
stage of (enter sinister organ music...) the ubiquitous Fungus Gnat.

Thing is- and this is important- it is my firm belief based upon
years of rotting more aroid tubers/ corms than I'd ever admit to
in a public forum, that these fungus gnat larvae are more akin
to a nasty secondary infection and are rarely if ever the primary
causal agent.

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From: Neil Gordon <neil at ng23.abelgratis.co.uk> on 2004.07.04 at 16:26:59(11714)
Thanks for the reply, that seems to clear that one up then!

When i got the tuber, it was dry and shrivelled, but plumped up nicely
when it was planted with a little water, then the bud poped up n
stopped, as i said earlier, so something happened several weeks before
i discovered it rotten.

On another note, I had an infestation of mealy bugs last year, and i
couldnt get rid of them until someone here suggested putting a little
vinegar in the insecticde as it dissolved their shells.

Does this acidic mix adversely harm or stunt the plants?

The mix worked well on the Aloes they were munching - the bugs were
unstoppable til i used that stuff!

Neil

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From: Dan Levin <levin at pixar.com> on 2004.07.04 at 22:06:59(11715)
Neil,

I must respectfully suggest that adding vinegar to your spray mix
resulted in a net positive only due to the buffering of your water's
pH, which resulted in greater efficacy of the diluted insecticidal
solution-- and not due to some acidic dissolution of body parts.
May I venture a guess that your tap has a somewhat high pH/
alkalinity/ hardness ?

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From: Neil Gordon <neil at ng23.abelgratis.co.uk> on 2004.07.05 at 00:38:52(11716)
On 4 Jul 2004, at 23:06, Dan Levin wrote:

Neil,

I must respectfully suggest that adding vinegar to your spray mix
resulted in a net positive only due to the buffering of your water's
pH, which resulted in greater efficacy of the diluted insecticidal
solution-- and not due to some acidic dissolution of body parts.
May I venture a guess that your tap has a somewhat high pH/
alkalinity/ hardness ?

In any event, if adding vinegar to your spray results in mealy slaying
synergistic pest control with no visible phytotoxicity, just keep
doing it
whatever the reason!

-Dan

Well, it was Balsamic ! ;-)

Neil

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From: "G. D. M." <doji at interpac.net> on 2004.07.05 at 01:16:48(11717)
Neil,

Be very careful in using vinegar around plants. I use it straight from store bought (cheapest) as a spray that top kills weeds almost immediately - within a few hours. If you continue, test a drop on a small section of leaf to see if a dead spot appears at your dilution first. If so, keep diluting or just save for salads!

I agree completely with Dan that the critical factor is the pH of the applied insecticide. Check with your water supplier, they test water quality and constituents constantly and will give you the pH of the water, as well as lots of other things, for the price of asking. Or invest in some pH test strips that will give you a number that is close enough.

Here in Hawaii a lot of plants coming in like, bananas, are required to go through a hot water bath of 140 F for up to 20 minutes just to kill whatever might be in them. Surprisingly, most survive. On tiny geophytes a much shorter time would be needed. Then cool off in room temp. H2O 'till the corm/bulb/tuber/rhizome is back to ambient temperature. I'll try to remember to do this this winter with some A. konjac offsets when they go dormant and report the results back to the list.

Gary in Hilo, where it rains every day, and in the winter it rains all day.

From: Phil Diamond <pmd at maths.uq.edu.au> on 2004.07.05 at 02:28:27(11718)
On Sun, 4 Jul 2004, Dan Levin wrote:

> in a public forum, that these fungus gnat larvae are more akin
> to a nasty secondary infection and are rarely if ever the primary
> causal agent.

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From: "Julius Boos" <ju-bo at msn.com> on 2004.07.05 at 13:14:09(11720)
>From: Neil Gordon
>Reply-To: aroid-l@lists.ncsu.edu
>To: aroid-l@lists.ncsu.edu
>Subject: [aroid-l] Amorph Blues
>Date: Sat, 3 Jul 2004 20:03:46 +0100

Dear All,
Allow me to put in my two-cents worth and suggestions of these fly larvae affecting the Amorphophallus corms. I am going through a simular situation on my job (commercial landscaping installations) with a large number of native Hymenocallis lily plants. The plant goes into a decline when it should be thriving, and when you dig up a bulb you find some large larvae that look like a fly species (NOT the Lepidoptera larvae of moth sps. that sometimes affects these lily species) that have eaten the roots and some of the basal layers of the bulb and are living in cavaties thay have eaten into the underside of the bulb. I think that perhaps both 'yours' and 'my' larvae are too large to be the lavae of the small balck insects I know as fungus gnats, and will try to collect a few more w/ bulb and confine them in a large plastic container covered in saran wrap w/ some holes poked in it, some dry soil below the bulb that th!
e larvae can pupate in, and see what comes out! We may be surprised, and I urge anyone who finds these larvae to do the same, makes treatment MUCH easier IF one knows ones enemy!! I used this method to identify what insect made the large galls on leaves of a bay tree, a beautiful yellow-and-black 'bee-fly' emerged, plus many tiny ichneumon wasps that were parasitizing other fly pupae!
Good Growing!
Julius

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From: "Wilbert Hetterscheid" <hetter at xs4all.nl> on 2004.07.25 at 10:21:39(11801)
Julius,

The maggots you describe in your Hymenocallis must be what we here in
Holland call "Narcissis fly" (Merodon equestris, of the fly family
Sirphidae), a very destructive creature. The fly deposits one or a few eggs
close to the neck of the bulb. The young maggots find their way down into
the bulb and eat it from inside out and you never saw it before they hatch
or the bulb rots away. Bulbgrowers here who fear they may have infected
bulbs, put these in warm water for a while (or even hot, ca. 60 C for a
short while), which is supposed to kill the maggots. Other than that the
only safe way is to have a small net over the developing plant or keep the
plant out of the open air (in a greenhouse). There are areas in Holland
where you simply cannot keep Amaryllidaceae out in the open.

Of course, this thing has nothing to do with fungus gnats.

Cheerio,
Wilbert

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From: "Julius Boos" <ju-bo at msn.com> on 2004.07.27 at 22:58:33(11842)
>From: "Wilbert Hetterscheid"
>Reply-To: aroid-l@lists.ncsu.edu
>To:
>Subject: Re: [aroid-l] Amorph Blues
>Date: Sun, 25 Jul 2004 12:21:39 +0200
>

Dear Wilbert,
Thanks so much for the information, it sure sounds like it must be this or some closely related fly that have effectively killed several thousand Hymenocallis lilys on a job I am doing, we have given up on treatments, they live and eat in the root area below the bulb and eventually the whole plant sucumbs to the infestation. Oh well!
Thanks again! Any lucck on seeds on the Pseudohydrosmes???

Julius

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From: "Wilbert Hetterscheid" <hetter at xs4all.nl> on 2004.07.28 at 16:18:13(11862)
Dear Julius,

The seeds of Pseudohydrosme..............NOW you brought it in the
open........!! Anyway, the ovaries are still growing sloooooowly but this
also happened the last time and eventually they did abort. I am still
surprised I managed to pollinate one effectively 7 years ago and since every
attempt has failed (this is to make known that I do NOT have a lawn of
Pseudohydrosmes.........).

Cheerio,
Wilbert

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