Soft Winged Flower Beetle

I thought this tiny beetle (2 mm long) was parasitized with something orange that was protruding between the metathorax and the abdominal sternites on the underside of the beetle (3rd picture). It is also partly visible in the second picture. In the fourth picture it was receding back into the beetle. Thanks to Thaptor, it turns out to be a bladder that the beetle extrudes when bothered and probably emits some kind of unpleasant chemical. See Thaptor's comment below. Family Melyridae, Subfamily Malachiinae.