How can Mymarommatidae wasps be distinguished from flies?

• A. They are smaller than flies.
• B. Mymarommatidae have only one vein in their front wings, while flies have two or more.
• C. They have spines on their legs that flies lack.
• D. They lack wings entirely.

Answer: (B)

Wing venation patterns are a reliable way to tell major insect groups apart. In Mymarommatidae, the forewing carries only a single vein, giving a very simplified wing venation. Flies, on the other hand (Diptera), have forewings with multiple veins visible, and their hindwings are reduced to halteres that help with balance in flight. This difference in the number of visible veins in the front wings is a practical, observable distinction even in tiny specimens and makes it a strong cue for separating these wasps from flies.

Size can be misleading because both groups include very small species; leg spines aren’t a consistent diagnostic feature across them; and Mymarommatidae do have wings (they aren’t wingless).