I came across this today and thought some might be interested. These bugs are common this time of year where I live (feeding on the Chinese flame tree mentioned in the article) and I was looking into them a bit. Box elder bugs are a common species in the US.
There is ongoing rapid evolution of soapberry bug mouthpart morphology in relation to the seed defense structures of its hosts. Rapid evolution in bug populations that feed on recently introduced sapinds is grounded with an ancestral pattern of coevolution between the bugs and the defenses of native sapinds.