Meandering along the trunk of a half dead crab apple tree, thought it was an ant until I noticed the antenna tapping. Flew or jumped suddenly at one point, back onto the tree. About 4-5 mm long, other species observed on tree include crab and jumping spiders, longhorn beetle larvae, rove beetles, ants, and leafhoppers. Small wings, white bar or pair of dots on abdomen, reflective and metallic in light.