Speckle-winged quill
Callibaetis ferrugineus hageni
Key Identification Characters - nymph 2
- Mature nymph 6-12mm long (excluding tails).
- Antennae long; 2-4 times head width.
- Heart-shaped gill plates on abdominal segments 1-7.
- Three tails equal length, fringed with fine hairs.
- Body color pale tan, olive, or olive-brown.
Similar nymphs: 2
Callibaetis nymphs are most likely to be confused with either Siphlonurus (Black Drake) or Ameletus (Brown Drake) nymphs. Both of these genera, however, have short antennae (less than twice the head width), which readily distinguish them from the long antennae (2-4 times head width) of Callibaetis.
Key Identification Characters - adult 2
- Two tails.
- Hind wings quite small and can be hard to see.
- Wing color in duns gray to brown with pale areas along venation. Wings of spinners clear or clear with speckled dark markings near leading edge (aka. speckle-winged quill).
- Body color of duns typically brown to gray; body color of spinners gray to almost black
- Body length 6-12mm.
Similar winged mayflies: 2
Callibaetis adults will most likely be confused with Siphlonurus adults. The small hind wing of Callibaetis, along with its wing color (light colored veins on duns and speckled dark markings on spinners), and body size, will quickly distinguish it from Siphlonurus or other similar looking two-tailed winged mayflies.
Habitat & Distribution 2
Callibaetis nymphs prefer lakes and ponds or very slow moving areas of streams, and are the most common and abundant mayfly in lakes throughout Oregon and other Western states. Like other swimming mayfly nymphs, they swim well and dart like small minnows when placed in a shallow tray of water.
Callibaetis are found in most lakes and ponds throughout Oregon, from the Willamette Valley to Eastern Oregon mountain lakes. Recent taxonomic revisions have combined four previously separate species into a single species, Callibaetis ferrugineus hageni. Two other less common species, C. pallidus and C. pictus, also occur in the region.
Life Cycle - Emergence 2
Mature nymphs swim to the water’s surface where the duns emerge. Dun emergence can occur from mid morning to late afternoon depending on weather conditions. Large numbers on the surface is common. After molting to the spinner stage, spinners mate in the air, and then females return to streamside foliage for up to five days while the eggs develop. Females return to the water from mid-afternoon to late evening to lay their eggs, which hatch almost immediately.
Callibaetis are one of the first mayfly hatches of the season with specific timing dependent on elevation. Callibaetis are also multivoltine (more than one generation per year).
Low elevation: April-May, July-August, and September-October
Mid to high elevation: June-July and September-October
Metolius: Not present
McKenzie: Possibly present in side channel sloughs
Necanicum/Nehalem: Possibly present in side channel sloughs
Sources and Credits
- (c) Jerry Schoen, all rights reserved, uploaded by Jerry Schoen
- (c) Jerry Schoen, some rights reserved (CC BY-SA)
