If design govern in a thing so small

Robert Frost's poem figures often in this blog, but not by design. (See here and here.)

Yesterday I photographed a mating pair of Orange Bluets. (Only the male, as you can see, is orange [bu confusingly, an immature male is pale blue], while the female is yellow-green. Lesson one in American Bluet-watching might be this: bluets are not all blue.)

I watched this pair for perhaps 15 minutes, during which time they flew from water plant to matting to plant in an oval area of only a few feet. When they landed here (see photo) below, I held my breath and tried again and again and again to get the perfect shot. I never fully succeeded in capturing the almost artistic beauty of their happy landing.

At first, I merely thought, Wow! What a happy accident!

Then I thought, Surely no accident. Otherwise, how would these tiny odonates know with whom to mate? A clue can be found in their different color. Recent research, of which a good bit is published online, suggests that damselflies (and dragonflies) see color. In fact, one fascinating PhD thesis states, "Numerous behavioural studies suggest that the diverse colour patterns function as a means for intersexual, intrasexual, interspecific, or intraspecific recognition and play a role in sexual selection, particularly in ischnuran damselflies that have sex-limited polymorphism."

Bingo!

Other researchers sequenced the genes of Ischnura elegans (Blue-tailed Damselfy, a species found in Europe) and "generated 428.744,100 paired-ends reads amounting to 110 Gb of sequence data." (Mind you, this damselfly averages about 31mm in length.) What did they find? Distinct color pathways supporting the fact "the odonate eye can detect colour from the ultraviolet (UV) (~300 nm) to the long wavelength (LW) (~700 nm) portion of the visible light spectrum and is capable of distinguishing polarized light" as well. (To put this in perspective, Wikipedia claims that humans that "a typical human eye will respond to wavelengths from about 390 to 700 nm."

So. Those Orange Bluets knew what they were doing when they hooked up. I can't help wondering if their final choice of ovipositing spot might also have been intentional. What fine camouflage the plant provides as she begins the long plunge underwater to deposit her fertilized eggs.

Long live the American Bluet!

(Whether or not design govern in a thing so small.)