Troutnut Forum > Fly Hatch Talk > egg sack color
This topic is about the Mayfly Family Heptageniidae
The "clinger" mayflies of this family are extremely prolific, although many species are not. These lesser species account for many of the curious mayflies you find in very small numbers but never associate with a major hatch. Not all Heptageniid species are so scarce; there are superhatches, too.
Heptageniidae can be broken into "groups" of similar genera to help the angler keep track of them. Although many of them contain closely related genera, they are not officially divided in this way by entomologists. Here are the groups:
Former Stenonema
The genus Stenonema now contains only one species, and its many former species are split between the newer genera Maccaffertium and Stenacron. These include the March Brown superhatch, Maccaffertium vicarium.
The former Stenonema species are mostly limited to the East and Midwest.
Former Heptagenia
While Heptagenia has held on to more species than Stenonema, many of its fishable hatches have been moved out to Leucrocuta, Nixe, and Ecdyonurus.
There are many former Heptagenia species across the continent, but they are far more important to fishermen in the West than in the East.
Two-tailed Nymphs
The closely related genera Epeorus and Ironodes are among the only mayflies to have just two tails as nymphs. They include the Eastern superhatch of Epeorus pleuralis, the Gordon Quills.
Suction Cups
The genus Rhithrogena is known for the gills of its nymphs. They extend below the abdomen in the front and the back and form a suction cup which helps the nymph cling to rocks. They can be very important but not very often.
Big Mouth Parts
The genera Cinygmula and Cinygma are marked by enlarged mouth parts which stick out to either side of the head a little ways. A few species produce fishable hatches, but none are of major significance. Read more...
There are 118 more specimens...
The Discussion
| LittleJ | May 18th, 2007, 9:33 pm | |
| Hollidaysburg Pa Posts: 131 | Just curious do vicarium have an orange egg sac. I got on the stream last night just before dark to catch the sulpher (I think invaria) spinner fall, and when I got there all I saw were swarms of orange egg sacks.IT was too dark to see the color of the fly, but I thought that sulphers were only yellow. Do they vary in color or was it vicarium. Thanks Jeff | |
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| GONZO | May 19th, 2007, 2:16 pm | |
| "Bear Swamp," PA Posts: 876 | Interesting question, Jeff. The spinners you saw were probably invaria. Whether the sulphur eggs appear yellow or orange or yellowish-orange depends a bit on prevailing light and might even vary a bit from stream to stream. However, I don't think that M. vicarium females fly around with an obvious ball of eggs attached (at least I've never noticed this). Instead, I believe that the eggs are held inside the abdomen and expressed a few at a time as they dip to the water. The invaria females eject the whole ball, often well above the water's surface. (This behavior can be frustrating for trout and fly fishers, especially when few of the spinners actually fall to the surface. One clever and time-tested tactic is to imitate the egg ball with some dubbing on a 22-24 hook.) The M. vicarium females would also be noticeably larger than E. invaria and would have two tails rather than three. If anyone can confirm these egg-laying observations, I would appreciate it. | |
| Martinlf | May 19th, 2007, 2:28 pm | |
| Palmyra PA Posts: 905 | The observation about visible external invaria egg masses vs. internal vicarium eggs is very interesting to me. I may have mistaken invaria for vicarium a week or so ago. Thanks, Gonzo. | |
| 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 | ||
| LittleJ | May 20th, 2007, 9:01 pm | |
| Hollidaysburg Pa Posts: 131 | I was back out this evening, and the orange egg sacs were def. invaria. I got there a little earlier and saw them in good light. Thanks gonzo for clearing that up, you saved me from tying up a bunch of vicarium duns w/ orange egg sacs. And The egg sacs were almost "glo bug" orange so apparently they do vary in color. Jeff | |
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