Chimarra sp. (Trichoptera: Philopotamidae) | Sam A. Baker State Park, Missouri
I recently found a folder in my files with a number of photos taken way back in April during a visit to Sam A. Baker State Park in the Ozark Highlands of southeastern Missouri. I never got around to posting them at the time, but there are some interesting photo series in the folder. One includes these photographs of an adult caddisfly (order Trichoptera). I remember seeing these insects in fair numbers resting on the foliage of shrubs alongside Big Creek and thinking they were some kind of archaic family of moths. Admittedly, it wasn’t until I got the photos up on the computer and saw the lack of any coiled proboscis for mouthparts, prominent maxillary and labial palps, and hairy rather than scaled wings that I realized what these were. My mistake is understandable—trichopterans are quite closely related to the order Lepidoptera, the two groups together forming an “ironclad” monophyletic clade (Wheeler et al. 2001).
The distinct palps, lack of proboscis and ”hairy” wings identify this insect as a caddisfly rather than a moth.
It was the beginning of this past season that I began practicing “hand-held” technique for insect macrophotography in earnest. I don’t use a tripod, so shooting insects resting on foliage requires that I brace my body to minimize movement. This is fairly easy if I can sit or crouch but very difficult if I have to stand. Moreover, even if I can manage to eliminate body movement, the plant on which the insect is resting often moves because of wind. What is really needed is a way to “lock” the relative positions of the camera and subject—movement is fine as long as both camera and subject are moving together. That’s where hand-holding the subject comes in… well, handy! I’ve learned to carry a small folding scissors in my waist pack when I am in the field, and by very gently grasping the petiole of the leaf on which the insect is perched with my left-hand thumb and forefinger and snipping the petiole with the scissors, I can detach the leaf without disturbing the insect and then hold it in any position and against any background that I desire. To take the photograph, I hold the camera in my right and and rest the lens on my left wrist or the base of my left thumb and then fine tune the position of the insect on the leaf while composing through the viewfinder. In this manner I not only lock the subject-lens distance but also precisely control the composition and background. This works best with the MP-E 65mm lens—its working distance of only 4″ at 1X and even less at higher magnifications is perfectly suited for this technique. I do also use this technique with my 100mm lens, but it is more difficult to do because of the longer working distance of the lens and resulting need to rest the camera further back on the left forearm. At any rate, these photos represent some of my earliest efforts using what I call the “left wrist” technique.
Among caddisflies, the blackish body and wings are characteristic for this genus.
I thank Dr. Robert Sites, University of Missouri-Columbia, for identifying the individual in these photos to the genus Chimarra in the family Philopotamidae (he also noted that male genitalic characters would be needed for species determination). Ferro and Sites (2007) listed three species of caddisflies in this genus from Sam A. Baker State Park (C. feria, C. obscura, and and unidentified Chimarra sp.).
REFERENCE:
Ferro, M. L. & R. W. Sites. 2007. The Ephemeroptera, Plecoptera, and Trichoptera of Missouri State Parks, with Notes on Biomonitoring, Mesohabitat Associations, and Distribution. Journal of the Kansas Entomological Society 80(2):105–129.
Wheeler, W.C, M. Whiting, Q.D. Wheeler & J.M. Carpenter. 2001. The phylogeny of extant hexapod orders. Cladistics 17: 113-169.
Copyright © Ted C. MacRae 2012
