Meet the sawflies
Despite what you may think from hearing the name, sawflies are not flies, but rather are related to bees, ants, and wasps (order Hymenoptera). In the Bagley lab, we are especially interested in Neodiprion sawflies, which specializes on hosts in the genera Pinus and Picea.
The name “sawfly” actually comes from the shape of the female egg-laying organ (or ovipositor). If you look closely in this image, you can see the ovipositor within the pocket this female is cutting. If you look closely at this image, you can see it is shaped very much like a tiny saw!
Sawflies are a great model system for studying the genetics of adaptation because they vary in a lot of interesting traits. For example, some species (including the redheaded pine sawfly shown in this image) can vary in body color and spotting intensity.
Sawflies also vary in the breadth of host plants they utilize, and in the traits they use to interact with those hosts. For example, the species shown above – the white pine sawfly, Neodiprion pinetum – uses one host: the thin needled white pine. Its sister species – the redheaded pine sawfly, N lecontei – on the other hand, uses at least 13 other hosts, all of which have much thicker needles than white pine. Accordingly, each species has traits that favor higher fitness on thin- or thick-needled pines, respectively.
Sawflies also have interesting defense traits. When agitated, the larvae curl up in a U-shape, and throw up a droplet of pine sap! If you keep bothering them, they may flail and try to apply the sticky drop to its attacker. This is mostly inconvenient for a human handling a sawfly, but would make for a very bad day if the attacker were an ant!
Parasitoids
We are still learning about the parasitoids (or lethal parasites) that attack Neodiprion sawflies. That doesn’t stop us from taking pictures of them though!
Photo courtesy of Ian Fefchak-Robinson.
Photo courtesy of Ian Fefchak-Robinson.
Photo courtesy of Ian Fefchak-Robinson.