I was kind enough to rescue this beetle type thing from the house and place it outside. Later I find that it is most likely a black vine weevil, Otiorhynchus sulcatus.
This beetle is probably the one who has been nibbling my rhododendron leaves. Although it is unsightly to have nibbled leaves, it won’t do too much harm to the plant. However, the larvae of this weevil may well be hard at work, unseen under the soil, chomping their way through the plant’s roots which will eventually kill it. So I suppose in its adult form it is the lesser of the two weevils.