Cottony cushion scale

Description:

Covered with fluffy-looking white or yellow wax, the adult insects are large (up to 10 mm long) and usually have the conspicuous feature of a large egg sac (2-3 times the scale’s body length) with ridges running the length of it. Icerya purchasi are mostly hermaphroditic and finding males in a population is rare.

Habitat:

The cottony cushion scale is a homopteran pest native to Australia. Its Australian host plant is kangaroo acacia, but it is found on a wide variety of woody plant species. It is especially common on Citrus and Pittosporum (cheesewoods). At about the same time as it reached California, Icerya purchasi was also introduced into New Zealand and South Africa. It is now found world-wide, especially where citrus grows.

Notes:

I found it on a rose tree (actually many of them) but I guess it was there due to the citrus trees we have around.