Hello,

I am wondering if you are talking about a blueberry bush, that grows the blueberry fruit or a viburnum shrub. There are several different varieties of viburnums but most are at least three foot high and wide and usually much larger. 

The leaf in the picture does not look like the leaf of a blueberry fruit bush.If you could send a picture of the bush that the insect is eating it would help me with identification.

There is an insect called a viburnum leaf beetle which larvae do defoliate the leaves of several kinds of viburnums. I have listed two articles about the VLB below. 

Please write back with more information.

Betsy B. - MGV

https://hort.extension.wisc.edu/articles/viburnum-leaf-beetle/

https://www.canr.msu.edu/news/keep_your_eyes_open_for_the_viburnum_leaf_beetles

Hello,

There are several varieties of viburnum that are favorites of Viburnum Leaf Beetle. Unfortunately, your Viburnum dentatum 'Blue Muffin' is one of them. 

The article from MSU (Michigan State University), listed in my first reply, explains what you should do to manage the infestation. Here are a few of the ideas in a nutshell: Support the beneficial insects that prey on the VLB by avoiding chemicals that may kill them, cut out twigs that are egg laying sites (most important), use chemicals only as a last resort, before flowering or after flowering and always follow all label directions carefully, it's the law. The use of horticultural oils, insecticidal soaps, and chemicals are most effective in late April, or early May.

 In the MSU article there is a link to Cornell University's report on VLB management. In addition to all the suggestions listed above, it mentions using a sticky substance called Tanglefoot, which could trap the insects as they make their way down the stems to get to the ground in order to pupate. This method though, has not been scientifically tested. As with any infestation, always clean plant litter off the ground and dispose of it in the trash.

Please read those articles from my first reply along with another article that I've listed below on VLB management. Again, feel free to write back with more questions. 

Betsy B. - MGV

https://ohioline.osu.edu/factsheet/anr-39