Scale Bugs
Posted on: 13/06/2015
Thursday October 22nd 2015
I spotted some red scale bugs on an olive tree the other day. Never having taken much notice of them before, I decided to take some leaves and photograph them later on. It's amazing how tiny things can be, but it was only on really close inspection that I saw some teeny little yellow critters on the same leaves.
Two days later, out of curiosity, I flipped one of the red scales over to photograph its hidden anatomy and was astonished to see hundreds of minuscule eggs and tiny mite-looking things. The eggs and newly hatched nymphs are roughly 0.1mm across. The red scale is a fraction under 3mm in diameter and the yellow critters are around 0.3mm long.
A new one for me, but it turns out that these are Saissetia oleae, a common pest of olives. The red scale is the adult female. She lays the eggs and protects them beneath her body until the nymphs (called crawlers) are mature enough to migrate to their own feeding spots. The yellow critters are more mature nymphs, but at this stage I have no idea how the change from yellow nymph to red featureless adult occurs. I'll try to photograph the stages, but at these tiny sizes it's a nightmare seeing what's happening!