This is my 3rd star jasmine in as many seasons that seems to be failing. First, I have no idea what is eating into it, I don't see anything, just the "chomp" marks! Second, the discoloring I know is from stress, probably the cold weather this past winter. I have tried to do everything I can from mulching over the winter to watering frequently in dry spells, to not watering so frequently. We have had a super long rainy season the last 2 years. There is good drainage in the spot it is in. The base soil is clay, but I amended it with really rich dirt when I transplanted it last year. It started to look bad right away, some of the leaves fell off and some of the shoots died. I do notice some new shoots on it in just the last few days. They are green, but still look pretty sparse. The top of the plant looks the worst. There is a hatched spider egg, that yellow looking blob is a bunch of baby spiders. I have never noticed anything like them in my garden before, and the plant was being eaten before they arrived! I LOVE these plants, but arrrrgh!!! What am I doing wrong??? I have a gardenia that looks similar, with some bug obviously munching on it. Who eats these things?
I have no idea -- but it sure looks like some kind of caterpillar or similar larva. I'd try neem oil, or perhaps BT (bacillus thuringensis), to protect against things that eat leaves (or suck on them in the case of neem, like aphids), while minimizing toxicity to other kinds of insects.