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Lycidae or Lampyridae larva? -dorsal - Pyractomena

Lycidae or Lampyridae larva? -dorsal - Pyractomena
near Miramichi, Northumberland County, New Brunswick, Canada
September 1, 2004
Size: about 15 mm
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Lycidae or Lampyridae larva? - Pyractomena Lycidae or Lampyridae larva? -dorsal - Pyractomena

Moved from Pyractomena.

Moved from Fireflies.


Not a larva... an adult female!
Found one similar in Mauricie National Park in Quebec on August 13, 2005. My collegues seem to all agree on a Lampyridae female, but don't know however which species.

characters? references?
What makes you say it's an adult? And what are the characters that identify this as a lampyrid - and not a lycid? What references did you consult?

Sorry, I should have specified
Sorry, I should have specified how I came to that possibility and shouldn't have written an affirmation in the subject title. However, I'm 99.5% sure of this conclusion.

As I've said, I've first consulted my colleagues (they're all entomologists) and they all seemed to agree on a lampyrid female. Then, I looked in "Borror and Delong's Introduction to the Study of Insects (7th Edition)", one of the most refered too book for family identification, and here's what I've read on pages 422-423:

FamilyLampyridae -- Lightningbugs, Fireflies: Many members of this common and well-known group have "tail light" segments near the end of the abdomen with which the insects produce light. These luminous segments can be recognized, even when they are not glowing, by their yellowish green color. During certain seasons, usually early summer, these insects fly about in the evenings and are conspicuous by their blingking yellow lights.

The lampyrids are elongate and very soft-bodied beetles, 5-20mm long, in which the pronotum extends foward over the head so that the head is largely or entirely concealed from above. The elytra are soft, flexible, and rather flat except for epipleurae. Most larger members of this group have luminescent organs, but many smaller ones do not.
The light emmited by these insects is unique in being cold. [...] .

During the day the lampyrids are usually found on vegetation. The larva are predaceous and feed on various smaller insects and on snails. The female of many species are wingless and look very much like larvae. These wingless females and most lampyrid larvae are luminescent and are often called "glowworms". There are about 125 sp. of fireflies in the U.S. and Canada, mostly in the East and South.

FamilyLycidae -- Net-Winged Beetles: The lycids (76 North American sp.) are elongate soft-winged beetles, 5-18mm long. They are somewhat similar to the soldier beetles, but may be readily recognizd by the peculiar network of raised lines on the elytra, with the longitudinal ridges more distict that the transverse ridges. Some western sp. (Lycus) have a distinct snout. The elytra in some sp. are slightly widened posteriorly. The adults live on foliage and tree trunks, usually in wooded areas. The feed on the juices of decaying plant materials and occasionaly on other insects. The larvae are predaceous. One of the more common members of this group is Calopteron reticulatum(Fabricius), 11-19mm long. The lytra are yellow, with the posterior half and a narrow cross band in the anterior part black. This insect's pronotum is black, with yellow margin. Most lycids are blackish, but many are brightly colored with red, black, or yellow. They are apparently distasteful to predators, and their coloration is mimicked by other beetles (certain Cerambycidae) and some moths (for example, certain Arctiidae).

I did not keep the specimen so it was impossible for me to pass it through the identification key. However, here are some characteristics that I observed, having it on my arm, and which correspond to lampyridae and not lycidae :

- Head prognathous;
- head retractile into tubular prothorax (Pterotus);
- distincly dorsoventrally flattened;
- some sp., possibly all, bioluminescent;
- widespread (females).

Of course, the key isn't a larval one. But, if you look at your ventral picture, you will see the "yellowish" segments which probably correspond to the bioluminescent organs. So, perhaps it isn't a lampyridae female, that's why I said 99.5% sure, but most characteristics seem to converge to this conclusion.

Hope I've explained enough!
Thank you for asking!

another possibility
I think one source of confusion is this photo, identified as the larva of a net-winged beetle (Lycidae); the photo appears with French text on this page.
Do you agree with that identification?

Finally, probably more a Lampyridae larva
Sorry for the delay, but I was waiting for a confirmation from Marc Braham, a coleopterist to whom I've been refered to from the president of the Coleopterists Society. I still haven't received the confirmation or invalidation yet, but if you go on his website ( there's a photo showing a very similar creature, and he identifies it as a Lampyridae last larval instar.

Personally, I would trust his identification more than one done by an amateur, what the AEAQ is all about (and don't get me wrong, this is not a pejorative comment, it's just that the probability of identifications mistakes with an amateur is a bit higher than with someone who's work is to study the family).

With respect,

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