My lilly pillies have a psyllid infestation. Psyllids are also commonly called plant lice (although they aren’t really like lice at all). They suck plant juices – most eggs are laid in the young foliage (in the case of lilly pillies it would be the red foliage) and they result in this ugly bumpy protrusions on the leaves as a result. Not all lilly pillies seem to be as susceptible to this pest. Tiny trev doesn’t seem to be affected as much. I have considered spraying with something like Rogor but I really don’t like spraying my plants and usually put up with the lumpy foliage – the plant itself seems to cope okay with the infestation. I think so long as you keep the plant healthy and feed it well and keep it well watered, the plant will recover from the infestation (I know mine has and I’ve never sprayed). If you do opt to spray the plant then you need to do so BEFORE the lumps appear ie you need to spray as close to egg laying time as possible because by the time you notice the galls/lumps on the leaves it’s already too late. For an environmentally friendly way of control, you can try the old yellow trap. Adult psyllids are attracted to the color yellow so if you have a sheet of yellow cardboard coated with something like petroleum jelly to trap them (they stick onto the cardboard as a result), you have a safe and effective means of controlling the psyllid population without using harmful chemicals. Neem oil is also effective to reduce numbers. I think the best thing to do is to buy plants that have been bred to be psyllid resistant in the first place – I didn’t have a choice with this one, it was given to me as a gift!