Is it a beneficial insect or a harmful insect?
the photo is not clear and it hard to say harmful or beneficial insect. It is the beetle and please kindly watch is there any damages to the plants and leaves. You don't need to worry if the number is small as the nature has its own protection ecosystem.
It is called the June beetle. At this stage it does not damage the crop, but in the larval stage it damages the roots of crops, especially corn.