|Option 1||Option 2|
|Anterior margin of pronotum densely fringed with long hairs, and dorsum of head flat and with bands of dense scale hairs (sf 19.272)||Anterior margin of pronotum and dorsum of head without dense hairs, or hairs not of type or arrangement as described at left |
|Case tapered, depressed, made of transverse bits of wood and bark (sf 19.480)|
|Remaining genera: Allocosmoecus, Amphicosmoecus, Anabolia, Arctopora, Asynarchus, Chilostigma, Chyranda, Clistoronia, Clostoeca, Crenophylax, Desmona, Dicosmoecus, Ecclisocosmoecus, Ecclisomyia, Eocosmoecus, Frenesia, Glyphopsyche, Grammotaulius, Grensia, Halesochila, Hesperophylax, Homophylax, Hydatophylax, Ironoquia, Lenarchus, Limnephilus, Monophylax, Nemotaulius, Onocosmoecus, Phanocelia, Philarctus, Philocasca, Platycentropus, Pseudostenophylax, Psychoglypha, Psychoronia, Pycnopsyche, and Sphagnophylax|
5 Example Specimens
This is a striking caddis larva with an interesting color pattern on the head. Here are some characteristics I was able to see under the microscope, but could not easily expose for a picture:
- The prosternal horn is present.
- The mandible is clearly toothed, not formed into a uniform scraper blade.
- The seems to be only 2 major setae on the ventral edge of the hind femur.
- Chloride epithelia seem to be absent from the dorsal side of any abdominal segments.
Based on these characteristics and the ones more easily visible from the pictures, this seems to be Grammotaulius. The key's description of the case is spot-on: "Case cylindrical, made of longitudinally arranged sedge or similar leaves," as is the description of the markings on the head, "Dorsum of head light brownish yellow with numerous discrete, small, dark spots." The spot pattern on the head is a very good match to figure 19.312 of Merritt R.W., Cummins, K.W., and Berg, M.B. (2019). The species ID is based on Grammotaulius betteni being the only species of this genus known in Washington state.
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.
No further information about this genus is available on Troutnut.com at this time.
|Go to Couplet 2|