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Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York
Blue-winged Olives
Baetis

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

Case view of a Pycnopsyche guttifera (Limnephilidae) (Great Autumn Brown Sedge) Caddisfly Larva from the Yakima River in Washington
It's only barely visible in one of my pictures, but I confirmed under the microscope that this one has a prosternal horn and the antennae are mid-way between the eyes and front of the head capsule.

I'm calling this one Pycnopsyche, but it's a bit perplexing. It seems to key definitively to at least Couplet 8 of the Key to Genera of Limnephilidae Larvae. That narrows it down to three genera, and the case seems wrong for the other two. The case looks right for Pycnopsyche, and it fits one of the key characteristics: "Abdominal sternum II without chloride epithelium and abdominal segment IX with only single seta on each side of dorsal sclerite." However, the characteristic "metanotal sa1 sclerites not fused, although often contiguous" does not seem to fit well. Those sclerites sure look fused to me, although I can make out a thin groove in the touching halves in the anterior half under the microscope. Perhaps this is a regional variation.

The only species of Pycnopsyche documented in Washington state is Pycnopsyche guttifera, and the colors and markings around the head of this specimen seem to match very well a specimen of that species from Massachusetts on Bugguide. So I am placing it in that species for now.

Whatever species this is, I photographed another specimen of seemingly the same species from the same spot a couple months later.
27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
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Hellgrammite Species Nigronia serricornis (Fishflies)

This is an especially abundant dobsonfly species in my collections.

Where & when

In 98 records from GBIF, adults of this species have mostly been collected during June (32%), May (30%), July (20%), and April (13%).

In 26 records from GBIF, this species has been collected at elevations ranging from 295 to 5279 ft, with an average (median) of 1926 ft.

Specimens of the Hellgrammite Species Nigronia serricornis

1 Male Adult
4 Larvae

Start a Discussion of Nigronia serricornis

References

  • Brigham, W.U., A.K. Brigham, and A. Gnilke. 1982. Aquatic Insects and Oligochaetes of North and South Carolina. Midwest Aquatic Entomologist.
  • Knight, Allen W. and C.A. Siegfried. 1977. The Distribution of Corydalus cornutus (Linnaeus) and Nigronia serricornis (Say) (Megaloptera: Corydalidae) in Michigan. Great Lakes Entomologist 10(2): 39-46.
  • Neunzig, H.H. 1966. Larvae of the Genus Nigronia Banks. Proceedings of the Entomological Society of Washington 68(1): 11-16.
  • Stehr, Frederick W. 1998. Immature Insects. Kendall/Hunt Publishing Company.

Hellgrammite Species Nigronia serricornis (Fishflies)

Resources
  • NatureServe
  • Integrated Taxonomic Information System
  • Global Biodiversity Information Facility
  • Described by Say, T. Order Neuroptera. Pp. 303-310 in Keating, W. H. (ed.). Narrative of an expedition to the source of St. Peter's River, Lake Winnepeek, Lake of the Woods, &c. &c. performed in the year 1823, by order of the Hon. J. C. Calhoun, Secretary of War, under the command of Stephen H. Long, Major U.S.T.E. Vol. 2. Carey and Lea, Philadelphia. (1824).
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