This is about the time of year that caterpillars hatch on blueberries from eggs laid there. I saw the first one on mine yesterday. Don't worry about it - this is perfectly fine and will not harm the plant. These caterpillars are part of a bigger food chain - birds will come and eat a few of them or feed them to their babies (baby birds eat insects for protein).

i get these each year, too and try to get every single one of them since they do so much damage. They will bend backwards into a 'c' shape.

forgot to say that i tap them off with a stick and drown them in soapy water same as i do the JB's. I don't really care in this one instance that they're part of a food chai n- i certainly don't want them multiplying to make the problem worse each year. they tend to stay all together in a fairly small area, esp at first. If you don't see any caterpillars (and they're bright- black yellow & red stripes) then it's too late to catch them this time.