Monday, December 11, 2017

Apatania incerta -- Little Mountain Casemaker -- at the Doyles River this morning

It's a casemaker that I don't see very often -- Apatania incerta -- but it's one of the things I was hoping to see this morning.  Beaty describes the case as "composed of mineral particles and strongly curved, cornucopia-shaped."  ("The Trichoptera of North Carolina," p. 85)  Pretty clear in the photos I've taken. 

The genus ID goes like this.

Mesonotum with two plates; metanotal sa1 sclerites absent; arrangement of sa1 associated setae in a linear transverse row...mandibles usually with uniform scraper blades (not toothed).  (Beaty, p.85)  Works for me.

On the species he adds: "larvae 6-9 mm; head dark brown to black; nota brownish-black; anterior metanotal plates replaced by row of about 20 setae; legs yellow brown."  But I'm not sure the species detail is needed.  In our new key, incerta is the only species listed for Apatania.  (Larvae of the Southeastern USA: Mayfly, Stonefly, and Caddisfly Species, p. 294)

With a Tolerance Value of 0.6, we can expect to find it only in very good streams.  And when the case is right side up, the larva is covered with a hood.  Normally, all we can see is the legs, but in this case, the part of the head also sticks out.

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