Troutnut Forum > Fly Hatch Talk > Anyone have hellgrammite experiences to share?
This topic is about the Insect Family Corydalidae
Hellgrammites are the vicious larvae of the Dobsonflies, some of the only trout stream insects which pose a biting threat to the angler. The pincers of the adult are even more frightening that the larva's, and they're aggressive enough to use them once in a while.
This family's life cycle does not create good dry fly opportunities, but the larvae may be eaten by trout year-round. They are a secret told only by stomach samples of well-fed trout. Read more...
There are 6 more specimens...
The Discussion
| Troutnut | November 18th, 2006, 3:19 pm | |
| Fairbanks, AK Posts: 1115 | I'm working on a magazine article about hellgrammites, which I think are a generally underrated food source and an extremely cool group of insects. I'm going to do a lot of research and combine it with my own experiences, but many of you have been fly fishing longer than I've been alive, so I'd like to see if any of you have stories about them -- catching big trout with stomachs full of them, finding trout rising to the dobsonfly adults, getting bit by these bugs, or anything else. | |
| Jason Neuswanger The Troutnut | ||
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| Shawnny3 | November 18th, 2006, 7:30 pm | |
| Pleasant Gap, PA Posts: 541 | I doubt it's helpful, but the first time I caught a hellgrammite nymph I put it in a jar with a whole bunch of other mayfly and stonefly nymphs and took them home to my tying bench. The flies I tied weren't very memorable, but it was pretty cool to watch the hellgrammite systematically bite every other nymph in half. Scary little buggers. -Shawn | |
| Jewelry-Quality Artistic Salmon Flies, by Shawn Davis www.davisflydesigns.com | ||
| Litobrancha | December 5th, 2006, 12:36 pm | |
| Knoxville TN Posts: 49 | Jason I was working on my M.S. on the Horsepasture River in NC and we had to camp in the backcountry near Lake Jocassee. There is an iron bridge there that stays warm after dark and it's a good place to lay and watch flying squirrels soar across the river, backlit by the sky. When I got up to go back to camp I turned my headlight on (we'd seen a lot of copperheads out at night here). Instantly I was mobbed by big Corydalus adults, probably twenty or so. Had to walk back in the dark. Other places nearby (Toxaway River) there were vertical rock faces over the stream that had literally thousands of egg masses (fifty cent piece sized white splotches) over the water. Would have loved to observe the oviposition frenzy that must have been. cheers | |
| Jason Robinson Research Specialist III UT Knoxville | ||
| GONZO | December 6th, 2006, 2:44 pm | |
| "Bear Swamp," PA Posts: 876 | Jason, I wish I had more to offer on this topic, but my experiences with imitating and fishing hellgrammites have been underwhelming. I've devised a number of imitations over the years. I've tried several curved imitations (the larvae tend to curl defensively like a salmonfly nymph when drifting), but I was unhappy with the size of the hook required and the large gaff-like gap that resulted. The most promising imitation was a realistic articulated pattern that allowed the use of a smaller hook. Unlike most of my experiments with hinged flies, however, this one was only a mediocre fly. I managed a few decent trout and even a couple of steelhead on the pattern before abandoning it. Even though I find dobsonfly and fishfly larvae in the majority of my seine samples, I doubt that they ever drift in significant numbers. And I've never witnessed the adults ovipositing on the water. I also doubt that the Woolly Bugger is taken for a hellgrammite even though that was the idea behind Russ Blessing's original. When trout are in a general feeding mode, specific imitation is seldom called for. The Bugger is just an extremely effective suggestion of life that succeeds well under general feeding conditions. Beyond this, I can share two little tales that may (or may not) be of interest. As a teen, I once spent the night on a large rock in the midst of a fastwater stretch of the Susquehanna at Duncannon. It was the middle of a solitary two-day float, and sleeping on the rock seemed like a good idea at the time. Well, the rock was uncomfortable, my sleeping bag was soaked, and the constant attention of several large dobsonflies made sleep impossible. In the morning, I set off down the river cold, wet, sore, and cursing the abominable insects. Years later, I was trying to teach some kids, who were participating in a summer camp, to fish (on the Lehigh River). Kids will be kids, and when the fishing (catching) was slow they'd pursue other forms of entertainment. My vain attempt to keep the kids on task was sharply interrupted by the shrill ear-splitting screams that only young girls seem capable of producing. I ran over expecting to see a watersnake slithering into the river. Instead, I discovered that two girls had been digging in the sand along the bank and their excavations had uncovered two large pupating hellgrammites (C. cornuta--the big uglies). I calmed the girls and explained about the alien monsters, but the thing that fascinates me to this day is the color of the larvae. They were bright yellow. This clearly indicated a recent molt, but it also seemed to suggest that hellgrammites undergo a molt while in their terrestrial stage prior to their final transformation into adults. I've never found any information that would confirm this, but I can think of no other explanation. I'll also pass along a worthless tidbit that I learned only recently. Corydalis cornuta is not only the scientific name for a species of dobsonfly but also for a species of flowering herb in the family Fumariaceae! | |
| Troutnut | December 6th, 2006, 3:13 pm | |
| Fairbanks, AK Posts: 1115 | I do believe hellgrammites drift enough to be significant at times. I base that on the fact that they turn up often enough in stomach contents on the rare occasion that I keep a trout. I've found 4 or 5 hellgrammites in one trout before. I don't know how often that happens, but it says to me that at least sometimes they're relevant in the drift. | |
| Jason Neuswanger The Troutnut | ||
| GONZO | December 6th, 2006, 3:42 pm | |
| "Bear Swamp," PA Posts: 876 | Jason, I agree that they can be significant, but it seems that their significance may have more to do with size rather than numbers. (After all, finding 4 or 5 caddisfly larvae in a trout's stomach is relatively insignificant, especially if it contains other prey as well.) It's an open question with me whether certain common but intermittently encountered food forms (especially large ones) provoke a specific focus or specific recognition by trout. I've had experiences that seem to argue for and against that notion. It appears to be a very individualized response. PS--I pushed the submit button accidentally before my previous post was complete. I wonder if you have any thoughts about the yellow terrestrial larvae. | |
| Martinlf | December 6th, 2006, 7:47 pm | |
| Palmyra PA Posts: 908 | My hellgrammite experiences are limited to the smallmouth and rock bass fishing days of my youth. It was commonly believed on my home river in Tennessee that hellgrammite larvae were one of the best baits ever, and they certainly were effective when my dad and I used them. We would kick seine for them in a riffle just upstream from an old rock steel and wood one lane bridge, turning over one well known big rock and always finding a multitude of the ugly bugs. I don't remember, though, ever finding any of them in the stomachs of fish we cleaned, though I remember vividly five or six reddish hornets we found in the belly of a fat rock bass. I can imagine him finding one floating along, but how did he encounter so many at one time? It's still a mystery to me. | |
| Louis Is it not an art to deceive a trout with an artificial fly? A trout! that is more sharp-sighted than any hawk . . . and more watchful and timorous than your high-mettled merlin is bold! --Izaak Walton The Compleat Angler | ||
| DMM | December 6th, 2006, 9:49 pm | |
| Posts: 141 | Corydalidae are considered fairly rare as aquatic insects go. You could say unimportant I guess. One thing to consider if you find these in a trout's stomach is selective feeding. Though low in abundance, one larva can offer a lot of energy to the fish. I guess I'm trying to say that you have to define what you mean by important. Except perhaps in some localized areas, they don't offer much in the way of drift, though. | |
| David | ||
| GONZO | December 7th, 2006, 12:20 am | |
| "Bear Swamp," PA Posts: 876 | Litobrancha wrote:There is an iron bridge there that stays warm after dark and it's a good place to lay and watch flying squirrels soar across the river, backlit by the sky. Sorry to interrupt this thread's train of thought, but I just had to call attention to this strikingly beautiful image. Thank you, Lito. PS--Has anyone else noticed the similarity between a hellgrammite and the thing that is placed in Chekov's ear in the Star Trek movie, The Wrath of Kahn? I wonder if it was the model for that alien life form? | |
| Troutnut | December 7th, 2006, 2:29 am | |
| Fairbanks, AK Posts: 1115 | I guess I'm trying to say that you have to define what you mean by important. Except perhaps in some localized areas, they don't offer much in the way of drift, though. Yeah, I'm sure they're not a major factor in any stream by body count, biomass, or any similar measure compared to the more common orders. My definition of "important" involves being eaten by trout in decent numbers, even if it's a very localized event. | |
| Jason Neuswanger The Troutnut | ||
| DMM | December 7th, 2006, 11:27 am | |
| Posts: 141 | GONZO--you had me stumped for a minute. It defeats the purpose of scientific names if multiple organisms share the same one. The answer is simple though...Corydalis is not an insect genus, Corydalus is. What would you do without me? ;) | |
| David | ||
| Brett | December 7th, 2006, 12:49 pm | |
| Martinsburg, WV Posts: 15 | I'm sorta new here, but thought I'd put in some anecdotal info on hellgrammites. I work along the Potomac River near Shepherdstown, WV...in an area which seems to have plenty of Corydalus cornutus. As they are attracted to the lights outside our work area at night, I can usually come out in the mornings during the summer and find adults on the buildings...at least those that weren't eaten by bats and nighthawks. Incidentally, Bats and nighthawks seem to like all parts except the wings and head capsules. I can usually walk the parking lot, picking up wings and divide by four to see how many were eaten on a particular night there. Mid to late-June appears to be the peak of the emergence...though I find adults from early June through early July. I have found larvae over 100 yards from the river...evidently looking for that "perfect spot" to dig in and pupate. I've heard that the riffles near Bluestone Dam, south of Beckley, WV, support an incredible number of hellgrammites and that the march out of the water to pupate can cause the roads to get a bit greasy. Perhaps the coldwater release and constant temp makes for a more "synchronous" emergence time. Incidentally I understand that the "pinchers" on adult dobsonflies are relatively useless. I handle them with forceps regardless. (I think it is the male who has long scissorlike pinchers) | |
| Brett Novice entomologist, fly-tyer and photographer | ||
| GONZO | December 7th, 2006, 12:54 pm | |
| "Bear Swamp," PA Posts: 876 | Thanks for the clarification, David. I agree that it makes no sense to have two species (one plant, one animal) with the same scientific name. I think you'll find, however, that a great many of the scientific and entomological sites have yet to catch up to this distinction. To see what I mean, you need only Google Corydalis cornuta. Numerous university and governmental sites use this name for the dobsonfly species in question. Upon checking Ethan Bright's site, I found the names Corydalus cornutus and Corydulus cornutus listed. I assume that the second is a simple typo. I trust that Corydalus cornutus is the accepted dobsonfly nomen, though the level of that acceptance leaves something to be desired. PS--Brett, welcome aboard. I'm glad you've decided to participate. My understanding is also that the formidable pincers of adult males are largely for show (unlike the larval mouthparts). | |
| Brett | December 7th, 2006, 1:06 pm | |
| Martinsburg, WV Posts: 15 | Checking my main bug manual, Merritt and Cummins' "An Introduction to the Aquatic Insects of North America, 3rd edition" it appears that Corydalus cornutus (which should be underlined or italicized, since it is Latin, is the accepted scientific name of the very common large megalopteran most of us know as hellgrammites or go-devils. By the way, I highly recommend the Merritt and Cummins book (now in a newer edition) if anyone seriously wants to get into bug work. It is very good in explaining the major aquatic insect orders, families and generra, but doesn't get into species. I recommend it is a basic text, with other species-specific books or papers for your area of interest. | |
| Brett Novice entomologist, fly-tyer and photographer | ||
| Martinlf | December 7th, 2006, 1:31 pm | |
| Palmyra PA Posts: 908 | This is pure trivia, and non-hellgrammite related, but Brett's comments on the discards of bats and nighthawks reminded me of an experience on the Delaware. I was fishing with a guide and we saw several mayfly wing and thorax combos floating along with missing abdomens. At first we hypothesized that a small trout must have bitten the abdomen right off. Then we saw a dragonfly intercept a sulphur mid flight, chew up the abdomen almost instantly, and let the wings and thorax fall, helicoptering like a winged maple seed. This is probably not news to the entomologists here, but some everyday anglers might not have yet noticed this phenomenon. Gonzo, do we have a wing and thorax tie yet? | |
| Louis Is it not an art to deceive a trout with an artificial fly? A trout! that is more sharp-sighted than any hawk . . . and more watchful and timorous than your high-mettled merlin is bold! --Izaak Walton The Compleat Angler | ||
| GONZO | December 7th, 2006, 1:44 pm | |
| "Bear Swamp," PA Posts: 876 | Brett, As a computer illiterate, I had to ask Jason how to italicize when posting. The procedure is to place {i} before the italicized material and {/i} after (except with straight brackets rather than the curly ones). By the way, the Perlidae specimens you brought to the FFF get-together were indeed Acroneuria spp. (Probably Acroneuria lycorias, though the achohol-faded markings were a bit difficult to recognize at first.) Louis, I haven't found trout to be that interested in dragonfly discards, but you never know. I am reminded of an evening on Mud Run when my fishing partner's fly mysteriously ascended skyward, towing a good portion of the tip of his fly line. His fly, while having a minimal effect on the trout we were pursuing, was sufficiently convincing to a large dragonfly--a testament to the powerful flight and lifting capabilities of these insects! | |
| Troutnut | December 7th, 2006, 2:14 pm | |
| Fairbanks, AK Posts: 1115 | it appears that Corydalus cornutus is the accepted scientific name of the very common large megalopteran most of us know as hellgrammites or go-devils That's interesting. I was fairly confident in my identification of most of the Corydalid specimens I've collected as Nigronia serricornis. If Corydalus is more common, I might have to rethink that. Would any of you with more detailed entomological training like to have a look at the specimens on this site and double-check my ID? I hadn't seen that name "go-devils" before. Can you tell me any more about its usage? I'll add it to the database. By the way, I highly recommend the Merritt and Cummins book (now in a newer edition) Are you talking about the 1995 version (third edition)? I've got that one, and you're right, it's great. I've heard rumors a new edition is out this year, but I haven't seen it for sale yet. About the dragonflies: That's a really interesting observation, and something I hadn't noticed before. I'm going to spin those posts off into their own discussion in the dragonfly section. | |
| Jason Neuswanger The Troutnut | ||
| GONZO | December 7th, 2006, 2:23 pm | |
| "Bear Swamp," PA Posts: 876 | Jason, According to Ethan Bright, "Only Nigronia serricornis is widespread in Michigan." He also says that "Corydalus cornutus is restricted to warm-water streams," though I have encountered them in larger "marginal" trout streams (like the Lehigh River). The two are pretty hard to mistake for one another. PS--While I certainly defer to the professionals on this, I've scanned the specimens, and they all appear to be Nigronia (and probably serricornis) to me. C. cornutus appears broader (more flattened) and has distinctive whitish gill tufts at the base of the lateral filaments. | |
| Litobrancha | December 7th, 2006, 3:44 pm | |
| Knoxville TN Posts: 49 | gonzo you are correct about corydalus gills being prominent. none of the specimens on this page are Corydalus, I think most are Nigronia. Can't see the last segment well enough on some to determine if the spiracles are long and uneven, if so those would be Chauliodes. Both can be rather large. The individuals mentioned above with the long swordlike mandibles are Corydalus cornutus males. The females have regular mouthparts and can bite a little. Doesn't hurt. Incidentally it is not a violation of the rules of nomenclature for plants and animals to share the same generic names, since they are different kingdoms. Can't recall the other examples of this but I know there are some. Corydalus can be found in trout streams, and I have seen it at high elevations ( | |
| Jason Robinson Research Specialist III UT Knoxville | ||
| DMM | December 7th, 2006, 7:56 pm | |
| Posts: 141 | Incidentally it is not a violation of the rules of nomenclature for plants and animals to share the same generic names, since they are different kingdoms. Can't recall the other examples of this but I know there are some. I just checked about 6 sources, and they all said that a genus and species combination can only be used once, regardless of kingdom. That is, every species on the planet should be able to be described by two words. This is the point of the binomial system. If you could reuse names in different kingdoms or domains, you would need a trinomial name. For example, Salvelinus namaycuh animalia. I am not trying to be hostile, but that's what I've always learned. If I am incorrect, I would appreciate a citing of a naming body or publication. Thanks. | |
| David | ||
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