By Njoywat
United Kingdom 
I've got an infestation of black larvae which hatch into small black sticky bugs at the bottom of the garden. I've used a pesticide on the ones at ground level but looked up and seen that they are all over my apple tree as well and I'd rather not use a pesticide to that extent if I don't need to. They don't seem to be damaging the plants but they aren't very nice. Anyone know what they are and whether they will go on their own accord?
I've added a picture in the hope it helps with diagnostics. he 'bugs' are small black insects. They are a little bit like what I would call a thunderbug, but they seem to be accompanied by a stickiness which is left on the plants they are on.
6 Jun, 2012
Answers
do you mean bugs as in an insect with sucking mouth parts, or a general term for any insect? {sorry I'm a biologist and the term bug does have a specific meaning} Doesnt ring any immediate bells. Any chance of a photo of the larvae and adult?
6 Jun, 2012
From the photo I'd say they are just black fly (aphids, like you get on broad bean plants). These certainly infest a wide range of plants, including nettles. The stickiness is the excretion of the sugary sap from the plant that they have been sucking.
If there are ladybirds around, their larvae will soon get the outbreak under control, and they always seem to disappear as the season advances.
I wouldn't worry too much as they certainly won't seriously harm your fruit tree crops.
7 Jun, 2012
I agrree with Bertie
Blackfly ,have you fed the apple tree ?? this occasionaly happens with lots of fresh growth .
Gg
7 Jun, 2012
Aphid infestation, specifically, as the others say, blackfly. If you find the infestation becomes exceptionally heavy, you may need to spray with a pesticide suitable for use on crop plants, and particularly if you start seeing lots of ants on the tree as well - they'll be 'farming' and protecting the blackfly so they can harvest the 'sticky stuff' - honeydew, which ants love. If the infestation is not too heavy, you can ignore it.
7 Jun, 2012
Thanks it sounds pretty conclusive. There's quite allot of them but I think I'll hold off with the pesticide and maybe try a blitz them with soap suds.
7 Jun, 2012
Any chance of a photograph? Black sticky bugs doesn't mean much to me, though I guess it might to another member...
6 Jun, 2012