Insects Eating Bouganvillea?

My plant is outdoors in a very sunny spot. It likes to be watered every day because of the heat. I live in Colorado and it has been over 90 degrees every day. If I forget to water the plant one day the leaves and flowers begin to droop.

I am now noticing that the leaves are being eaten and there are large light brown spots on the leaves. There are some very tiny black dots on the back of the leaves and it appears that the light brown spots are areas where something is eating the underside of the leaf. I have looked for insects, perhaps caterpillars, but found no evidence. The areas where it is evident that something is eating the leaves, there are holes in the leaves. What can I do?

By Julie G