On 01/03/2016 19:03, Bob Hobden wrote:
"Jeff Layman" wrote

It's not mealy bug which is the pest with me, but scale insect. Then

Generally found oil and wetting agent painted on them works for me a bit
like meths and a stiff brush against mealy. Never quite kills them off
completely but keeps them from becoming a nuisance.

you get black mould everywhere on the leaves below from their
droppings! And, like you say, RSM is a permanent pest too. Bayer's
"Plant Rescue" used to work pretty well as it contained abamectin, but
because it also contained thiamethoxam it was removed from the market.
It would be useful to have something with abamectin back, as there is
nothing active against RSM. I am in total agreement with you about
biological control being too variable for the amateur.

When I repotted my mandarin/clementine/whatever (I lost the label
years ago) it sulked for a couple of years losing all its leaves and
was attacked by numerous pests. But I persevered with it. Last year it
grew lots of nice new foliage, and at present has hundred of flower
buds just about to open. I'll bet the RSM and scale insects can't wait...

Scale is the big pest as far as I'm concerned. We have two Lemon trees,
two Tahiti Limes, an Orange, a Grapefruit, an an ornamental lime thing
with huge fruit. The best way to deal with scale if you want to use the
fruit is to blast them off with a sprayer pumped up to max pressure
containing water a a tiny bit of detergent. Yes you get soaked too and
it's a long process going over every branch and leaf but it works.

I tried something like that on a Bay tree with scale insect and the
leaves all dropped off within a week. It never recovered

I didn't want to use anything noxious on it for culinary use.

There must be a decent systemic that will get scale insect if you can
forgo eating any fruit for a year. I haven't found anything that will
still control red spider any more. Controlling humidity helps a bit but
basically they are now immune to almost everything.

I have my own local variety of sap sucking mite that aren't rsm and only
target snowdrops as far as I can tell. Makes the leaves go silver later
in the season but doesn't seem to do them any harm.

--
Regards,
Martin Brown