Soyedina alexandria and S. calcarea (Plecoptera: Nemouridae), new stonefly species from the eastern Nearctic region and notes on the life cycle of S. calcarea

english

2006

volume 2, issue 6

Plecoptera 

Prirodoslovni muzej Slovenije
(Obvezni izvod spletne publikacije)

Two new species of eastern Nearctic Nemouridae, Soyedina alexandria and S. calcarea, are described from the karst regions of Tennessee and Kentucky, U.S.A. Illustrations and scanning electron micrographs of the male and female stages are provided and diagnostic characters separating these two species from closely-related S. vallicularia are presented. Soyedina vallicularia was studied across its broad range to address potential morphological variation, which may impede the ability to differentiate S. alexandria and S. calcarea from S. vallicularia. A diagnostic key is provided for the males of S. vallicularia, S. alexandria, and S. calcarea. Nymphs of S. calcarea were collected monthly over a two-year period from the Kentucky type locality and size frequency histograms of head capsule width revealed a univoltine-slow cycle. Adults emerged between February and April, and early-instar nymphs werepresent by May suggesting a direct hatch of eggs. The life history patterndisplayed by S. calcarea is similar to that demonstrated by S. vallicularia in Quebec and Ontario.

16.09.2009