n.swift predatory fly having a strong body like a bee with the proboscis hardened for sucking juices of other insects captured on the wing
同义词：bee killer
英汉双解大词典
robber fly
1.
N（名词）
any of the predatory dipterous flies constituting the family Asilidae, which have a strong bristly body with piercing mouthparts and which prey on other insects 强盗蝇 (Also called bee killer, assassin fly)