Only just seen your message. They are citrus bugs. The black ones are
mature: the young ones are the colour of new citrus leaves,
yellowy-green, and smaller. Both are shield shaped What you do is get an ounce of strong pipe tobacco (contains nicotine)
(old dog-ends will do at a push) soak it in a bucket of water - if you
can heat it so much the better - until you have a brown liquid. Get some pure soap flakes - `Lux' is ideal - add that to the nicotine
solution and dissolve it. You'll have to work out how much to put in.
You are going to spray it so it can't be too thick. Spray the tree. The soap holds/sticks the solution to the bug/plant and
the nicotine kills the bug. This works for aphids (green or black fly)
or any other little beastie that sits on any leaf like caterpillars. The rain washes it all off so you can then eat the lemons or whatever
with no problem. If you don't want to be bothered with the nicotine (it is a poison) you
can use just the soap solution (as strong as you can get it and still
spray without clogging things up), because insects `breathe' through
their carapace (outer covering) through little holes and the soap clogs
the holes up and they die. You just wash it off before
harvesting/cooking. Hope this helps next season. Cheers, K. --
vesting/cooking. Hope this helps next season. Cheers, K. -- | 
