Hibiscus attacked by insects - holes left in leaves

[NickF]

We have a few young hibiscus plants in our garden and every year they get badly attacked by something. I checked the leaves for a few days and I could not see anything. Maybe there are some insects that are coming during the day and doing all the damage. They seem to prefer one of the two plants. Two years one of them almost died. It was the larger of two and now it is half the size of the other plant.

Can anybody advise what is causing this and how can I fight against it?

Thanks,
Nick

[dstrat]

I'm no expert but could it be shot hole? It's a fungal disease

[abwal]

I suspect it is a chewing insect (grasshopper?) or caterpillar. You could spray the leaves with a garden insecticide.
Sprays that do not kill, but simply repel are probably best - though not as readily available- as these will not kill bees. Home remedies can be made using garlic and chilli (search Google).