bean flies
 

Hi all,
I'm new here so I don't know if this subject has been discussed. Actually I
think I might have contributed to this group back in the 90s but it may have
been another gardening one. My question regards bean flies. The general
practice around here is to use Rogor, and that works well enough, but years
ago I was told that a weak solution of phenol sprayed at emergence and each
week for about four weeks worked even better. I would try it, but I cannot
remember what ratio phenol to water to use. I'm thinking on the lines of a
teaspoon to a litre. Does anyone use phenol in this way, and, if so, what
ratio is used. Thanks, Dan

bean flies
 

" Dan" writes:
My question regards bean flies. The general
practice around here is to use Rogor, and that works well enough, but years
ago I was told that a weak solution of phenol sprayed at emergence and each
week for about four weeks worked even better. I would try it, but I cannot
remember what ratio phenol to water to use. I'm thinking on the lines of a
teaspoon to a litre. Does anyone use phenol in this way, and, if so, what
ratio is used. Thanks, Dan

Hi Dan. I believe Rogor has fallen into disuse by most home gardeners
because of its toxicity. I know nothing about the use of phenol on edible
crops. Phenol (carbolic acid) doesn't have a good report card, though, and
I see where just one gram of it can be fatal.

Just to clue us in, by "bean flies" do you mean the tiny white flies (about
2 mm in length) that can be found in plague numbers on the foliage of carrots,
tomatoes and curcubits?

Apart from sticky yellow strips to attract and hold whitefly, I frequently
hear Comfidor suggested as an effective spray.

I've seen tiny spiders (what we'd call money spiders) catch white flies, so
insecticides would kill off the spiders, too.
--
John Savage (my news address is not valid for email)

bean flies
 

Dan wrote:
Hi all,
I'm new here so I don't know if this subject has been discussed. Actually I
think I might have contributed to this group back in the 90s but it may have
been another gardening one. My question regards bean flies. The general
practice around here is to use Rogor, and that works well enough, but years
ago I was told that a weak solution of phenol sprayed at emergence and each
week for about four weeks worked even better. I would try it, but I cannot
remember what ratio phenol to water to use. I'm thinking on the lines of a
teaspoon to a litre. Does anyone use phenol in this way, and, if so, what
ratio is used. Thanks, Dan

My dad always said that hilling the beans helped to keep away the bean
fly. It doesn't seem to make sense but I still do it. Only ever had a
couple of beans die from bean fly.

Lionel.

bean flies
 

Just to clue us in, by "bean flies" do you mean the tiny white flies
(about
2 mm in length) that can be found in plague numbers on the foliage of
carrots,
tomatoes and curcubits?

Apart from sticky yellow strips to attract and hold whitefly, I frequently
hear Comfidor suggested as an effective spray.

I've seen tiny spiders (what we'd call money spiders) catch white flies,
so
insecticides would kill off the spiders, too.
--
John Savage (my news address is not valid for email)

Hi John,
No the "bean flies" I am referring to are small black flies that lay eggs on
the leaves almost immediately the plants emerge. The resultant larva burrow
into the stem and eat the inside of the plant. The plant either dies or
survives to give only a very poor crop. I was led to believe that the phenol
did not stay too long in the plant but mainly disguised it from whatever
senses the flies used to locate it.
Thanks for your input,
Dan

bean flies
 

"none" ""lionel\"@(none)" wrote in message
...
My dad always said that hilling the beans helped to keep away the bean
fly. It doesn't seem to make sense but I still do it. Only ever had a
couple of beans die from bean fly.

Lionel.
Hi Lionel,
Hilling does not keep away bean fly. If the plant is hilled, when the bean
fly larva eat the inside of the stem the plant puts new roots out above the
main damage. This, in many cases, and especially if the infestation is not
too bad, allows the plant to survive and give a reasonable crop.
Here in North Queensland it helps, but unless we have had very cold weather
for this part of the world, some insecticide is necessary or the plants die.
Thanks for your input,
Dan

bean flies
 

" Dan" writes:
No the "bean flies" I am referring to are small black flies that lay eggs on
the leaves almost immediately the plants emerge. The resultant larva burrow
into the stem and eat the inside of the plant. The plant either dies or
survives to give only a very poor crop. I was led to believe that the phenol
did not stay too long in the plant but mainly disguised it from whatever
senses the flies used to locate it.

I looked for a photo of a bean fly on Google images, and don't recognise it
as a problem in the temperate regions.

I have a couple of suggestions.

You could try phoning one of the radio gardening advice programs and asking
there. Even though the consultant may not know, there are likely to be many
listeners who do. The Sydney programs take calls from all over Australia.
You could try asking Don Burke (2UE, Sat/Sun mornings 6-8am, ph. 131332
or try Graham/Sandra/Linda Ross (2GB, Sat/Sun mornings, 6-9am, ph. ???? so
get it from the web site, http://2gb.com).

I mentioned your phenol idea to my mother, a keen vegetable gardener. She
has never had a problem with bean fly, but said that her sister-in-law
who lived in Bundy used to spray her beans with phenol just like you
said! But aunty died over 25 years ago, so it's too late to ask her
whether she found the technique effective. Perhaps post your question on
rec.gardens.edible as there would be a lot more gardeners from tropical
zones (southern USA) there.
--
John Savage (my news address is not valid for email)