Larval description

One of my goals for my research is a complete larval description. Many species of insects are formally described based on their adult morphological characters, and the larval features tend to be secondary or omitted completely. In the case of the caterpillars in Acronicta, some of them have been well documented while others have been largely ignored. A complete larval description will help me learn important characters for my group and practice my photography, illustration, and SEM techniques.

I chose an uncommon species whose adults seldom come to lights, and whose caterpillars have not been described aside from a few lines in some field guides. Of course, being uncommon is going to make my job more difficult, but I do have some specimens and life history data collected last summer that I can start with.

The species is Acronicta falcula, a handsome caterpillar which feeds on Corylus plants (Hazel). Its common name is, predictably, the Corylus Dagger Moth. I have started drawing the chaetotaxy or setal map, in which I look at a specimen under the scope and try to draw the correct arrangement of hairs and other features on each segment. I am also attempting a life-like pen and ink illustration. So far I have sketched out the body plan, and I am adding the hairs as I complete my setal map. It is difficult to get the hairs right from the photo, and I want to ensure my drawing is correct. It currently consists of several layers of tracing paper, which will all be copied down in ink and shaded with stippling.

I also chopped up a specimen, dried it, sputter coated it, and am awaiting scope time next week to get SEM images of its various parts. I think the raised warts and hairs will be quite interesting.

Posted on March 2, 2012, in Acronicta, Acronictinae, Illustration, Invertebrates, Lepidoptera, Noctuidae. Bookmark the permalink. 3 Comments.

  1. Love the photo of your sketches, scientific drawing is a dying art and I’m glad there are younger people keeping it alive still. Good luck on making larval descriptions, there’s a lot of work to be done!

    • Thanks! I LOVE drawing, and feel that scientific illustration is a really important skill to perpetuate… maybe it’s just because I suck at using photoshop, haha! But really, I get the most enjoyment out of doing things with my hands, whether it’s drawing or sewing or pinning moths or cleaning out the caterpillar containers.

  1. Pingback: Sneak peak « caterpillarblog

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Ryerson Lab

Functional Morphology, Sensory Biology, Behavior, Biomechanics

I spell it nature

Trying to make sense of the world through science and language.

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