" 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)