By Somhairle
Renfrewshire,
Scotland 
Something is eating my centaurea dealbata. I planted this last year and before the plant could develop, the leaves were skeletonised. This year, the same seems to be happening. I have sprinkled slug pellets around the plant but that seems to have had no effect. I have also checked for signs of bugs and there are none. However, I have now sprayed them with a general pesticide.
Does anyone have any idea what could be munching on my plant?
21 May, 2016
Answers
Its most likely a caterpillar or some larva that hatched directly on the plant so pellets wouldn't stop them. They could be very difficult to see sometimes. They camouflage really well and are nocturnal. If you go out at night with a flashlight and magnifying glass, you should be able to spot the culprit.
Try spraying your plants with soapy water using dish detergent. Be sure to spray under the leaves where most of them hide.
21 May, 2016
Thanks for the help. I have now a couple of photos which may make things a little easier. I am not sure if the plant is still being eaten. It is certainly not as bad as it was and is not nearly as bad as it was last year when I first put it into the ground.
You should be able to make out where some of the leaves have been stripped and some others leaves with holes at the edges. Those do look like caterpillar holes, but the stripping seems more like slugs.
23 May, 2016
Maybe it's both.
23 May, 2016
Photos would help alot, of the whole plant, the stem and both sides of a few leaves.
21 May, 2016