Today I’m having fun working on something I quite enjoy – looking at insects through a microscope. What I’m specifically doing is an attempt to determine which Omus species of Carabidae (or Cicindelidae, if you’re inclined to elevate Cicindelids to the family taxonomic unit). To this end I’ve been reading published keys by Hatch 1953, Choate 2001 & 2003, Pearson Knisley & Kazilek 2006 and several other published papers; I’m quite enjoying working through the specimens I found on the property over the past several months, along with material from further afield. The question: are the large dark beetles found here Omus? and if so, which species? (there are several described species they could be).
What is amazing to me is that I can locate much of the published information while not standing at the reference desk in a large university library – the mterial is available online. I don’t need to be within walking distance of a reference collection, as many of the collections have been photographing their specimens and making the photographs available online. Upshot is I can do a lot of digging from anywhere in the world that has a network connection.
The laptop computer is a great way to access all kinds of information. Here it’s displaying the photoshop z-stack (focus stack) of images I’ve taken of the Cicindela that’s under the microscope – visible above the laptop screen in the image.
The microscope is a Leica MS5, which is a parallel-optics path stereo microscope. This means that additional elements can be inserted into the optical path without parallaxis shifts occuring. The photo-tube is inserted above the body and below the viewing head of the microscope, and the Nikon D90 is plopped onto the optics tube. One can get photos such as this:
This is the business end of a Tiger Beetle – they feature huge mandibles with sharp teeth, big eyes that are good at seeing movement, and metallic colours which makes them a favorite for beetle folk. Here I’m trying to capture an image that shows the clypeus extending laterally past the antenna socket.
This is a better image of the clypeus extending lateral to the antenna insertion socket. The images needs annotation to indicate this, I’m working on that part of the problem later on tonight. This is actually a z-stack image built from 15 images from the Nikon D90. Each image features a slightly different focal plane as the camera is moved to descend through the part of the insect I would like to havei n focus. Photoshop has a z-stack (focus stack) feature that aligns the images and then constructs elaborate image masks to bring out the elements of the image most in-focus and assemble the whole stack as one image. Lots of mathematics going on in Photoshop.
The big question: are the six black nocturnal cicindelids genus Omus? And if so, which species? Stay tuned to find out, as I’m still trying to find out!
Fun one can have on when not on the boat. And is there a relationship between the beetles and the boat? Answer: yes. The boat is named Tiger Beetle, and tiger beetles are fast, carnivorous, colourful, and have a silly name (who would ever name a tiger affter a beetle, eh?), and I’ve had fun painting the two tiger beetles on the sides of the boat. So above are what the real thing looks like.
Choate P.M. 2001 The ground beetles of Florida (Coleoptera: Carabidae) including tiger beetles, tribe Cicindelini. (prepublication manuscript) Dept. Entomology and Nematoology, University of Florida.
Choate P.M. 2003 Illustrated Key to Florida Species of Tiger Beetles – (Coleoptera: Cicindelidae).
Hatch, M.H. 1953 The Beetles of the Pacific Northwest Part 1: Introduction and Adephaga. University of Washington Press.
Pearson D.L., Knisley C.B., Kazilek C.J. 2006 A Field Guide to the Tiger Beetles of the United States and Canada: Identification, Natural History, and Distribution of the Cicindelidae. Oxford University Press.