Bug o’the Week – the Missouri Bee-killer Robber Fly
Howdy, BugFans,
Robber flies are a very cool bunch of flies that we have visited a number of times in the past. Besides being awesome-looking, these “bearded” flies (sometimes called Assassin flies) are predators, and they are not shrinking violets. In the Field Guide to the Insects of North America, Eric Eaton says that “Robber flies (family Asilidae) are to other insects what falcons are to other birds.”
Robber flies’ modus operandi is to spot an insect from their perch, grab it (and they will go after insects larger than they are), inject it with saliva to both kill it and soften its insides, and then perch and ingest the liquid through a tube called the hypopharynx. They eat lots of insects that are agricultural pests, but they haven’t been formally deployed as biological controls because they are equally likely to eat honey bees and Monarch butterflies.