Introducing Pristiphora fructicola!

Pristiphora fructicola male on the left, female on the right (notice the saw on the "tail" of the female)

It was the end of May/beginning of June 2015.  I was spending my days looking for huckleberry flowers in the mountains south of Bozeman, Montana.  It was a bit disappointing... after the summer of 2014 that I spent among big, dense huckleberry shrubs in the Yaak (in far northwest Montana), the small, scraggly, flower-sparse plants in the Gallatin National Forest were pretty boring.  The lack of flowers meant a lack of documented pollinators.  I caught a few bumble bees and a some small solitary bees in the genus Andrena, but it wasn't the lovely days of watching (and listening to) large numbers of bumble bees that I had enjoyed the previous summer.

Still, it turned out that there was great discovery to be had.  Right around the end of anthesis (the flowering period of the plant), I started to notice tiny yellow insects flying in and around the branches of the huckleberry plants.  I thought they were tiny yellow wasps and collected a bunch.  When I got back to the lab and told my advisor about the large number of little wasps I was collecting, he was intrigued and asked to see them.

Under the scope, the first realization hit me.  These insects did not have the constricted waists that are characteristic of bees and wasps.  They had four wings (so they couldn't be flies), they didn't have long piercing/sucking mouthparts (so they couldn't be true bugs), they didn't have armor-like fore-wings (so they couldn't be beetles), and they clearly weren't butterflies or dragonflies.  They looked the most similar to bees and wasps... that's because they turned out to be in the same family (Hymenoptera).  They are just the lesser-known cousins of bees and wasps, sawflies.

Hymenoptera:  top = wasp (yellow jacket); middle = sawfly (figwort sawfly); bottom = bee (honey bee). Notice the constricted "waist" between the thorax and the abdomen on the wasp and bee, but not on the sawfly. (google images)

Sawflies get their common name from the fact that females literally have saws at the tips of their abdomens.  This is part of the ovipositor (i.e. egg laying organ).  The saws are used to cut into plant material so that eggs can be laid inside plants.  It is for this reason that sawflies are often considered pests of economic importance.  For example, the wheat-stem sawfly is a tiny insect that has wreaked havoc on wheat crops in the U.S.  The eggs are laid in the stems of wheat and the larvae feed on the insides of stems, preventing water and nutrients from moving through the plant, eventually causing the death of the plant.  Much research has gone into breeding wheat that is resistant to these sawflies or studying and releasing tiny wasps that prey on them.

Identifying insects to species is not easy... at all.  My advisor and I keyed out my tiny sawflies to the Hymenoptera family Tenthredinidae.  This is the largest, most diverse family of sawflies.  Using some obscure literature, Mike figured out that they belonged in the (former) tribe Pristolini, but there seemed to be some confusion about identification of insects in this subgroup.  There are relatively few species in Pristolini, and our sawflies didn't seem to match any of the species descriptions.  We went through the large volumes of Hymenoptera in America North of Mexico, looking for other sawflies known to be found in, on, or around huckleberries.  None of the recorded species matched our specimens.  It was definitely a mystery!

The next step was to send photos and eventually specimens to Dr. David Smith, a retired research scientist at the Smithsonian Museum of Natural History, who is the known sawfly expert.  He dissected the lancet (saw) out of one of the specimens we sent him, and he compared it to the two most similar species. It turns out that characteristics of the lancets (things like number of teeth, shape of the teeth, shape of the lines, etc.) are important diagnostic features.  It was pretty clear that our species was different from the other two. That meant I had discovered a new species!!

Female sawfly lancets: top = Pristiphora resinicolor, middle = our mystery sawfly; bottom = Pristiphora ferruginosa
photo taken by David R. Smith

 So what happens when a species, previously unknown to science, is discovered?  There's actually an International Code of Zoological Nomenclature that lays the ground rules for naming and describing new species, changing the name of a taxonomic group, or synonymizing two names. This is not a book I recommend reading.  When I showed interest in learning more about the process, even my advisor told me that reading "the code" would be really boring.

The International Code of Zoological Nomenclature .

The main thing that happens is that a very detailed species description has to be written (following a standard format).  The species description needs to be detailed enough that another person could identify a specimen and distinguish it from other similar species.  Within the published species description, the author/describer gives the new species a name.  Names often come from Latin words describing key characteristics or locations.  Sometimes species are named in honor of the collector (if the collector is different from the author) or another scientist that the author wants to honor.  It is even possible to have a sense of humor when naming species:

Gollumjapyx smeagol is a cave-dwelling dipluran named after the Lord of the Rings character.
(image found on Twitter)

Scaptia (Plinthina) beyonceae is a golden-tailed fly named after Beyonce.
(image from telegraph.co.uk)

Agathidium vaderi is a slime-mold beetle named after the Star Wars bad guy.  The Cornell University entomologists who named this beetle also named slime-mold beetles after Bush, Cheney, Rumsfeld, and Pocahontas (among others).

The names of the author/describer become part of a new species official name, so it is considered redundant and "bad form" to name an insect after yourself.  Dave and I decided to name our sawfly  fructicola from the Latin words for "fruit" and "house."  This is because I found larvae happily feeding inside green berries late in the summer.  The tricky thing is that I found the larvae inside fruit at different study sites than those where I collected adults-- frustrating irony.  So, we can't be sure that the adults and larvae are the same species.  There could be other similar sawflies sharing the same habitat.

Live sawfly larva found inside undeveloped huckleberry fruits.

It is likely that the female laid eggs in the flowers' ovaries and as the fruit developed so did the young insect.  We think that the larvae likely pupate and then fall to the ground to overwinter in leaf litter, emerging as adults to mate and lay eggs early in the spring.  This is all speculation, however, none of this is documented.  We also have no ideas on population numbers, life span, range, diversity, etc.  All we know is that we found a species that was active during a short window of time in and around one particular plant.  That leaves a lot left to discover!

In order for a new species to become "official" the species description has to be published.  That occurred this week for Pristiphora fructicola Smith and Dolan.  Our paper was published here in the October 2016 issue of The Proceedings of the Entomological Society of Washington.  Sure, it's a journal that has very narrow readership, but it's a peer-reviewed journal nonetheless.


---
"Discovery is one of the greatest joys, and it is still there to be had in abundance." 

-Howard E. Evans from Life on a Little-Known Planet