These are nymphs, but perhaps the Anchor Stinkbug? They are predators; did you observe any behavior?

Someone told me they were a Chinese Beetle and were pests which made sense to me since they were clustered in a group of 20 or so. Most predators are solitary, no?

I'm pretty sure that they are not beetles at all, but 'true bugs', such as one of the thousands of species of stinkbugs. The nymphs of stinkbugs look quite a bit different than the adults.

The assumption that predators are solitary would not be a true one. Many of the assassin bugs and predatory stinkbugs hatch from a large cluster of eggs deposited by the female. The nymphs are obliged to 'hang out' together until they eventually grow wings and can fly away.

I think its more like a leaf beetle which do eat plants . Its not a nymph because it has a hard outer surface .Rick

I'm still sticking with the truebug nymphs. ;-) If you look at images of many of their nymphs (I'll post one for you), you can see that there is quite a resemblance.

The reason that I think that these insects are the young of a stinkbug or true bug of some sort is that the adult wings have not formed yet.

The attached link is one of the pretty 'bugs', the Harlequin bug. These are nymphs.

Here is a link that might be useful:

Thanks for both of your help.

Even though assassin bugs hatch from a large clutch of eggs don't they end up trying to eat each other rather than hang around?

Nice picture *shivers*