Bee fly

6572.    This insect emerged as if being born from our deck railing while we were outside enjoying a coffee. Warm sunny day (about 25C), mid-morning. We first noticed sawdust dropping from the railing as if something was eating at the deck and then this emerged, spread its wings out and crawled over to the railing edge to get into the sunlight. Photo taken just minutes after it emerged. Delhi, ON. Canada

Number 6572. This is a bee fly (Diptera: Bombyliidae). They are parasitic on bees, primarily ground-nesting bees, but some species specialize in attacking carpenter bees, such as in your case.