Home and Garden IPM from Cooperative Extension

Photo Gallery: Sawflies (suborder Symphyta – also includes horntails and wood wasps)

Sawflies belong to the insect Order Hymenoptera, making them relatives of ants, bees, and wasps. They are sometimes referred to as “plant wasps” and even more often as “stingless wasps” since they highly resemble wasps but do not sting. Sawflies undergo complete metamorphosis, meaning they have four life stages: egg, larva, pupa, and adult. The adult females are characterized by a saw-like appendage called an ovipositor, which they use to cut or ‘saw’ into plants when laying their eggs. This is how they get their common name. Sawfly adults generally have a broad connection between their thorax and abdomen, unlike the narrow waist found in other types of wasps.

The larvae of sawflies are often mistaken for caterpillars due to their similar appearance and plant-eating habits. However, there are key differences that can help distinguish them: Sawfly larvae typically have six or more pairs of fleshy prolegs on their abdomen, while caterpillars have five pairs or fewer. They are also hairless, have really tiny dot-like eyes on a shiny, smooth, button-like head, and many species exhibit a common behavior of frequently curling their posterior end downwards just a little, especially when they’re disturbed.