[rogertb]

Short and sweet, out of 20 various brassicas this one has a problem, anyone recognise it please ?

Many thanks

Roger

[mumofstig]

That's mealy aphid attack 

RHS advice is here
https://www.rhs.org.uk/advice/profile?PID=656

[rogertb]

Thanks mumofstig ... I have to keep my eyes peeled ... thankfully. so far, only one plant.

[Middlesexbloke]

Deal with them promptly or they'll spread to other plants and it'll be so much harder to eradicate. Mealy aphids can ruin a crop in my experience, covering everything in black mouldy deposits and affecting the vigour of the plants drastically. Had then most times I've grown brassicas under enviromesh; this year under regular pigeon netting they seem fine, bizarrely!

[rogertb]

Thanks Middlesexbloke ... I have the brassicas under debris netting. the uncovered row without net was where the offending plant was (see the gap) it was covered in the same way as the others in the photo (cover removed for plant removal and photo) ... also I'm now away for 2 weeks so I guess if there are more about I might fall prey ! I had a good look at the other plants this morning and couldn't find anything .... fingers crossed !

Roger