What are these reddish-brown growths on my succulent plant?

Question

I recently discovered upon close examination of these strange, small, brown-reddish growths on the stems of my plant (picture below). This was a recent occurrence, after I placed the plant on the windowsill in my kitchen (close to where a lot of greasy cooking occurs, unfortunately).

I was wondering if anyone happens to know what these growths are called, and if so whether they are endangering the plant. And if it is indeed harmful, how should I try to remove them and also prevent further growths?

Answer 1

Scale infestation - brown scale in fact, not that it matters. If you've got some rubbing alcohol or some methylated spirits, dip a cotton bud (Q tip) in and rub off the scale from the stems, being careful not to douse the stems or leaves in the spirit solution. The immature ones on the back of the leaves (paler, smaller) are susceptible to oil sprays such as Neem oil, or you may find you can wipe them off, so inspect all backs of leaves and stems and try to clear them all away.

UPDATE: No, not really, no prevention, just inspect the plant occasionally once you think you've got rid of them all. They can produce a lot of generations a year on houseplants, and their eggs are usually covered with a sort of white fluff (if you look closely, you can see white fluff extruding from the mature scales in the picture). The nymphs (those lighter ones on the backs of the leaves) hatch out and as they mature, attach themselves to the thicker stems, where they remain permanently. There are insecticidal sprays you can use (check what's available where you are) which might be easier for recurrent infection. Also check the pot - sometimes mature scales settle there too, on the lip of the pot and even on the outside occasionally. These can be removed with the alcohol method described above.