Allocapnia muskogee, Grubbs & Sheldon, 2008

Grubbs, Scott A. & Sheldon, Andrew L., 2008, Allocapnia Muskogee And A. Menawa, New Species Of Snowflies (Plecoptera: Capniidae) From The Talladega National Forest Region Of Eastern Alabama, U. S. A., Plus Four New State Records, Illiesia 4 (11), pp. 99-109: 99-104

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Allocapnia muskogee

sp. n.

Allocapnia muskogee   sp. n.

( Figs. 1-8 View Figs )

Material examined. Holotype ♂ and paratype ♀, U.S.A., Alabama, Cleburne Co., unnamed tributary to Swan Branch , Shinnabone Creek , Talladega National Forest , 24 km SW Heflin, 28 December 2007, S.A. Grubbs ( INHS). GoogleMaps   Additional paratypes: same but 9 ♂, 4 ♀ ( WKU); same but 17 February 2003, 1 ♂, S.A. Grubbs ( WKU). Clay Co.   GoogleMaps , unnamed tributary to Cheaha Creek   GoogleMaps , Talladega National Forest   GoogleMaps , 19 km N Ashland, 33.4397°N, 085.8387°W, 4 December 2006, 1 ♂, A.L. Sheldon ( WKU). Cleburne Co.   GoogleMaps , unnamed tributary to South Fork Terrapin Creek   GoogleMaps , Talladega National Forest   GoogleMaps , 33.8220°N, 085.5148°W, 22 December 2007, 2 ♂, A.L. Sheldon ( WKU); unnamed tributary to unnamed tributary to South Fork Terrapin Creek   GoogleMaps , Talladega National Forest   GoogleMaps , 4 km S Vigo, 33.8865°N, 085.5559°W, 26 January 2008, 2 ♂, 2 ♀, S.A. Grubbs ( WKU). Georgia, Lumpkin Co., fast stream, 12 mi NW Cleveland, 30 December 1964, 1 ♂, Hensley and Smith ( INHS, Catalog No. 11964).

Male. Body length 3.5–5.0 mm. Wings reaching 6 th to the 9 th abdominal terga. Seventh abdominal terga unmodified. Dorsal process of 8 th terga markedly produced, nearly perpendicular to the plane of the abdomen ( Figs 1–2 View Figs ); process with tuberculate transverse ridge that is partially ( Figs. 3–4 View Figs ) to nearly completely separated medially ( Fig. 5 View Figs ), with lobes that appear subtriangular in dorsal aspect ( Figs. 3, 5 View Figs ) to subtruncate in anterodorsal aspects ( Fig. 4 View Figs ). Apical limb of epiproct 2X length of basal limb, moderately and roundly expanded distal half laterally ( Fig. 1 View Figs ), nearly parallel-sided and unmodified dorsally ( Figs. 6–7 View Figs ).

Female. Body length 4.0–5.5 mm. Wings reaching 7 th terga to beyond tip of abdomen. Eighth abdominal sterna darkly sclerotized medially, only slightly sclerotized laterally, terminating in triangular projection posteriorly; separated from 7 th sterna by membrane ( Fig. 8 View Figs ).

Etymology. The specific name, used as a noun in apposition, is in reference to the indigenous Muskogee, or Creek, Native Americans who occupied the upper Coosa and Tallapoosa River valleys flanking the Talladega National Forest area prior to European settlement. The common name, Muskogee snowfly, is proposed for this species ( Stark et al. 1998)

Diagnosis. Allocapnia muskogee   is most similar to A. wrayi Ross   and A. mystica Frison   , the only two members of the A. mystica   species group ( Ross & Ricker 1971). Allocapnia zekia   was described by Ross (1964) as a possible local variant of A. wrayi   and also placed in the A. mystica   group (Ricker & Ross 1971), but was subsequently synonymyzed with A. wrayi   by Kondratieff & Kirchner (1982). Allocapnia muskogee   is included in the A. mystica   group.

Allocapnia muskogee   is distinguished from the other two members of this group most easily by details of the epiproct, in both lateral and dorsal aspects. The ratio of the apical limb length to the basal limb length varies across the A. mystica   group. The apical limb of A. mystica   is markedly shorter than the basal limb, approximately 0.75X the length ( Figs. 17–18 View Figs ). In contrast, the apical limb of A. muskogee   is 2X the length of the basal segment ( Fig. 1 View Figs ) and 1X – 1.5X for A. wrayi   ( Figs. 9–10 View Figs ). Kondratieff & Kirchner (1982) illustrated the variability of the epiproct for Maryland and Virginia specimens of A. wrayi   , depicting apical to basal limb ratios of 1.5X (their Fig. 1 View Figs ) and 1X (their Fig. 2 View Figs ), which is similar to the 1.5X ratio shown here for two separate series of specimens from western Maryland ( Figs. 9–10 View Figs ). Additional specimens of A. wrayi   examined from Maryland, Virginia, North Carolina and South Carolina pertain easily to this concept.

In lateral aspect the apical epiproct limb of A. muskogee   is rounded distally ( Figs. 1 View Figs ), and differentiated easily from both A. wrayi   and A. mystica   . For A. wrayi   the distal end of the epiproct is truncate with a raised mid-dorsal keel ( Figs. 9–10, 13– 15 View Figs ), while the apical half of the epiproct of A. mystica   bears a subdistal notch ventrally ( Figs. 17–18 View Figs ). When viewed dorsally the epiproct apical limb of A. muskogee   is parallel- or nearly parallel-sided and broadly rounded distally ( Figs. 6–7 View Figs ). In contrast, the epiproct apical limb of A. wrayi   is spatulate ( Figs. 13– 15 View Figs ) and for A. mystica   the epiproct apical limb tapers markedly distally.

The dorsal process of the 8 th abdominal terga of A. muskogee   , A. wrayi   , and A. mystica   are similar and provide a less objective means of differentiating between species. The dorsal process lobes of A. muskogee   vary from subtriangular to truncate ( Figs. 3–5 View Figs ) while the lobes are more rounded for both A. wrayi   ( Figs. 11–12 View Figs ) and A. mystica   ( Figs. 19–20 View Figs ).

Females of A. muskogee   can be distinguished from A. wrayi   and A. mystica   by the posterior triangular projection of the 8 th abdominal sterna ( Fig. 8 View Figs ). Allocapnia mystica   bears a broadly rounded posterior margin ( Fig. 24 View Figs ) while the posterior margin of A. wrayi   varies from broadly rounded to slightly subtriangular ( Fig. 16 View Figs ). Ross & Ricker (1971) did not distinguish the females of A. mystica   and A. wrayi   .

Although A. mystica   is distributed broadly across the unglaciated landscape east of the Mississippi River ( Kondratieff & Baumann 2000; Stark et al. 2008) and is common throughout Alabama ( James 1972), it is not a resident of upland or montane streams in the Talladega National Forest area. Allocapnia wrayi   is regionally distributed in small, upland streams from southern Pennsylvania south to northwestern South Carolina, and has yet to be collected west of the Appalachian Mountains ( Ross & Ricker 1971; Kondratieff & Baumann 2000; Stark et al., 2008). The single male specimen of A. muskogee   from northern Georgia currently represents the northern end of its range.

Remarks. The type locality is a small, intermittent stream situated within a broad, flat valley. The only other stonefly species collected with A. muskogee   , and only from the tributary to Cheaha Creek site, were A. aurora Ricker   , A. menawa   n.sp., and A. recta (Claassen)   .


USA, Illinois, Champaign, Illinois Natural History Survey


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Western Kentucky University