Kyle: I read a paper by Kühsel et al. (2016) that covers my interests in allometry, physiology, and imaging techniques. This study used 3D surface models created with a structured light scanning method (26 min of scan time per specimen) to measure surface area. The authors showed that it captured surface area about as accurately as a synchrotron, coincidently using that of our collaborators at the Karlsruhe Institute of Technology. The researchers also used Amira, a program that I’ve used too, to create and explore these 3D models.
Scaling can be isometric or allometric. Isometric scaling has usually been assumed when calculating expected water loss since it is difficult to accurately capture the surface area of an organism. The effect of allometric scaling can be calculated from the residuals of the SA/V2/3, and the authors found that this explained deviations in water loss unaccounted for by isometric scaling.
The authors also made several statements about organism size and surface area that I think would be great to keep in mind for my tiny wasps.
- Smaller organisms generally have higher SA/V
- High surface area to volume ratio is associated with high water loss
- Small insects with high SA to V experience highest water loss
Dendrocerus, the genus that I study, has many species which have incredibly broad ranges, and many of my North American Dendrocerus occur in the dry southwest. I wonder if there are measurable trends in body size or surface area and occurrence? I’ve also always hypothesized that the presence of an incredibly large spiracular atrium might serve to prevent water loss, and I’m very curious whether the character will turn out to be phylogenetically relevant or species-distribution relevant?
Carolyn: I worked through Microscopic Anatomy of Invertebrates volumes 11B and 11C, focusing on chapters concerning the morphology of fat bodies and other structures in the abdomen, as well as the morphology of glands. I think next week I’ll focus on rereading the papers that everyone from István’s “Know Your Insect” seminar found about glands and techniques for studying them. (That was really a great class, I like how it’s still relevant and helping me a year later!)
I also read a new book called The Sting of the Wild by Justin O. Schmidt. Each chapter focuses on a different type of stinging apocritan wasp, many of which he has experienced first hand. (At the end, he provides a table of the pain of different stings.) This book is very well written! The author is very passionate and is good at explaining difficult concepts in a way that’s easy to understand. The author is also not afraid to go in depth—he even discusses Dufour’s gland, something I had never heard of before taking István’s morphology seminar.
Emily: This week I have been reading Dragonflies and Damselflies: Model Organisms for Ecological and Evolutionary Research, edited by Alex Córdoba-Aguilar. In particular, I focused on the chapter by Mark McPeek about the ecological factors driving Odonata. Species of Odonata are drawn to certain aquatic environments for oviposition, and thus, larvae develop in a variety of different bodies of water. Success of larvae is influenced by many factors including parasites, predators, and larval density. However, very little is known about the demographics affecting the adult populations on a local scale. Furthermore, the factors shaping the distribution among aquatic water bodies is poorly understood (e.g., what is causing some species to prefer harsh, brackish water?). It really makes me want to read deeper and see if there’s research about any phenotypic distinctions between the taxa residing in these varied habitats.
Andy: I had this paper by Barrows et al. (2016) open in a browser tab for over a month. I finally got around to reading it … and decided that the outcomes of their research really need to be discussed in my ENT 432 course. We already have a mini lecture and required reading (Tewksbury et al. 2014) about natural history. I think I will not only extend this discussion but also design a major exercise around the topic – an immersive, Thoreauesque study of insect natural history that results in field notes and specimens. I pushed my chicken scratches on this topic to our new, more generic Insect Biodiversity and Evolution GitHub repo if you’re interested. I can’t wait to develop these ideas further and experiment withe exercises this summer!
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