Happy Tuesday y’all!
The past week has been an interesting mix of fun and work for me – I got to hike around few of the parks here in state college,
took a trip to Ten Acre Pond with the Frost Crew and Dr. Hal White of University of Delaware, who has been collecting Odonates there for decades,
enjoyed some of the the local fourth of July festivities,
and got a little mouthy…
My father use to refer to me as “loquacious” as a child, but I’m not speaking to my lack of ability to button my lip here. Instead, what I mean is that I’ve spent a good deal of time lately carefully dissecting the mouth-parts out of Australasian evaniids and examining them for characters useful for identification
I’ve been pleasantly surprised with myself so far – I have basically NO fine motor skills (I couldn’t draw a straight line to save my life), but I’ve managed to get a number of these guys pulled apart without doing too much damage to them.
Once dissected, I mount the head and mouth parts on a slide with blue tack and snap a few photos (I’d share, but none of these are ready yet. I’m trying to get pretty high quality images, so I’m relying on focus stacking of 10 to 50 images smashed together to form one picture. I’m not trying to be closemouthed about these, I just haven’t been able to get them compiled yet). Right now I’m focusing on a few specific characters (I’ve done my best here to de-muddle some of the terminology here, as some of it is quite a mouthful): the carinae (ridges) on the insides of the mandibles (jaws) and on the shape of the labium (the floor of the insect mouth). I’m noticing a few interesting things:
- Some, but not all, of the evaniids I’m looking at have a secondary carina on the mandibles that encircles the inside of the oral cavity.
- Some, but not all, of the evaniids I’m looking at have a ledge on the prementum (front part of the labium) which gives the structure a shape similar to an inverted T if looked at in a “head on” fashion.
- Neither of these characters seems to follow along with either the two genera I’m examining as keyed out by currently used characters.
I’m hoping that continued work with these specimens will throw some light on whether or not these differences are actually important in separating monophyletic groups. For now though, I have no idea!
There was discussion yesterday of the need for poetry about Odonate collecting. I don’t think I’ve quite captured its essence in these few words but, regardless, I’ll leave you with a haiku:
Summer afternoon,
dragonflies soar through the blue —
missed ev’ry last one.
Andy Deans says
Awesome poem! Pretty much captures the majority of my experience as well. I also like the custom dissecting gear, with fine oak handles. Maybe I’ll commission you to make me a set!