About sawflies

Handling sawfly specimens

Mounting

In most cases, having a sawfly specimen mounted facilitates identification. Having the insect on a pin allows a user to manipulate the specimen and see diagnostic characters without touching it and risking damage to the body.

Sawflies are easiest to pin within the first 24 hours of collection or immediately after being stored in alcohol, before the body dries and becomes rigid and fragile. A stainless steel insect pin of appropriate size (0-4) should be pushed, as vertically straight as possible, through the right side of the mesoscutum. Because sawflies are bilaterally symmetrical, this off-center approach ensures that an undamaged “copy” of the pierced area exists on the opposite side. The insect on the pin should be generally positioned horizontally, as if it is sitting on a flat surface.

correct pin insertion location for specimens
correct pin insertion location for specimens (Perreyia tropica)
correct alignment for pinned specimens
correct alignment for pinned specimens (Lophyrotoma zonalis)

When mounting sawfly specimens, it is important to make sure the wings, which are naturally positioned folded over the dorsum, are positioned so as not to obscure diagnostic wing venation or body parts. This is most easily accomplished by ensuring the wings are not plastered to each other or the body while the specimen is drying. Using an insect pin to carefully lift and separate the wings while pinning the specimen can help with this. The wings are very fragile, and any such manipulation should be performed carefully. Sawfly wings can also be spread laterally, like a butterfly; this creates dramatic specimens, but isn't necessary for identification (see photos below).

Each of these positions retains visibility of the abdominal terga, meta-thorax, lateral sclerites, and complete wing venation. Additionally, the legs of the specimen should be arranged along the sides (versus underneath) of the body, as symmetrically as possible. Antennae should be somewhat straightened and separated from one another, so the segments can be clearly seen and counted, and the antennae don’t obscure head characters. If possible, it can also be useful to spread the mandibles and gently pull the ovipositor out into view.

correct pin insertion location for specimens
wings spread laterally (Macremphytus lovetti)
correct alignment for pinned specimens
wings spread vertically (Aglaostigma rubens)

Once a specimen has dried, these features can no longer be manipulated without risk of breakage. It is time consuming and challenging to re-hydrate a specimen, so it is worth the extra initial effort to prepare the specimen with the wings, legs, and antennae in position. Use small pins to hold them in place while drying occurs.

For small specimens (<5 mm in length), it may be necessary to point-mount or double mount to not destroy or obscure the thorax (see examples of point-mounting and double mounting below).

correctly aligned point-mounted specimen
correctly aligned point-mounted specimen; point is glued to the right side of the thorax (Ophrynopus nigricans)
correct alignment for pinned specimens
correctly aligned double-mounted specimen; specimen is pierced with a minuten pin and affixed to a strip of pinning foam, then mounted on a regular-sized pin (Onycholyda sitkensis)

Labeling

Mounted specimens should be labeled with thorough information that enhances the scientific value of the specimen. A good label contains as many of the following items as are known about a specimen: collecting locality (including state/province, county, and city), geographical coordinates, date of collection, name of collector, collecting method, associated plant, and habitat or behavioral notes. The label should be placed on the pin, below the specimen.

Immatures

Sawfly larvae are soft-bodied, so they need to be treated differently from adult specimens. The most common way to store larvae is in glass vials of 70% EtOH. Labelling is equally important with larvae. Best practice is to keep the label inside the vial with the larvae, which minimizes the risk of dissociation that could occur with labels affixed to the vial. Inscribe the label with archival ink so it will not be degraded by the fluid.

A note about collecting

If you are making many observations or collections of sawflies in natural environments, especially of genera not well covered by existing literature, consider using a site like iNaturalist.org or BugGuide.net to log your specimen data. There it can be accessed by researchers and members of the public to expand knowledge of range, host associations, and seasonality.