Insect and Spider Identification: CLOSED: Sap sucking insect, 1 by Percnco

Percnco wrote:
There is an insect on my nursery plants.
It surrounds itself in some sort of white goo, and seems to like the joints of the leaves and the stems. I can pick the white stuff off and when I crush it there is like a purplish mess, presumably the insect I'm crushing.
Picking it off works when there is only a few but they are infesting my liechart pines at the moment.
If any one knows what they are and a suitable treatment for them, much appreciated.