Isoperla laucki Baumann & Lee, 2009

Sandberg, John B. & Kondratieff, Boris C., 2013, The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species, Illiesia 9 (5), pp. 34-64 : 48

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Isoperla laucki Baumann & Lee


Isoperla laucki Baumann & Lee  

( Figs. 7 View Figs a-d)

Isoperla laucki Baumann & Lee 2009   . View Cited Treatment

Holotype ♂, California, Humboldt County, Dragsaw Spring @ Rd 13N01.  

Male. Aedeagus: sclerotized posterior process present; body with one posterior lobe, one large dorsal lobe, and a pair of small anterolateral lobes ( Fig. 7a View Figs ); one posterobasal patch of spinulae scattered below the sclerotized process and a long narrow posteroapical spinule patch concentrated above the sclerotized process ( Figs. 7 View Figs a-b); sclerotized process length <0.5 mm, digitate, apex a blunt point, and capable of complete ( Fig. 7a View Figs ) to partial eversion ( Fig. 7c View Figs ). Abdominal terga 8-9, 9, 9-10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to blunt apices ( Fig. 7c View Figs ). Vesicle: pedunculate, length subequal to width, constricted near base with curved lateral margins, wider and rounded at apex ( Fig. 7d View Figs ).

Isoperla laucki   is most similar to I. marmorata   ( Table 1 View Table 1 ), with diagnostic differences in aedeagal spinule patch shape, location of sclerotized process, and sclerotized process shape. The spinules form an elliptical shaped patch distinctly separated from and placed above the insertion of the sclerotized process. The more rounded and in one case, bi-hemispherical shaped spinule patches of the I. marmorata   complex are all placed above and adjacent to the insertion of the posterior sclerotized process. The I. laucki   sclerotized process length is <0.5 mm, has parallel lateral margins, and a bluntly rounded apex. The sclerotized processes of the I. marmorata   complex are longer (approaching 0.5 mm), and have expanded dorsal and ventral margins forming a blade-like apex with variable distal margins.

The above male description, including live everted aedeagal characters, agrees with the previous description of the aedeagus based upon scanning electron microscope preparation ( Baumann & Lee 2009, figs. 1-8). It was not noted in their methods if the live everted aedeagus was fixed in hot water. An unfixed aedeagus, after live eversion, will usually invert or deflate slightly, and might explain the slightly larger and expanded dorsal lobe in our study ( Fig. 7a View Figs ).

Additional Material Examined. CALIFORNIA, Humboldt Co., Unnamed tributary of Boise Creek , Hwy 299, 01/ V /2011, J.B. Sandberg, B.C. Kondratieff, 1♀ ( JBSC)   .


Royal British Columbia Museum - Herbarium














Isoperla laucki Baumann & Lee

Sandberg, John B. & Kondratieff, Boris C. 2013

Isoperla laucki

Baumann & Lee 2009: 48