The Genus Megaleuctra Neave (Plecoptera: Leuctridae) In North America Author Baumann, Richard W. Author Stark, Bill P. Box 4045, Department of Biology, Mississippi College, Clinton, Mississippi, U. S. A. 39058 E-mail: stark @ mc. edu stark@mc.edu text Illiesia 2013 9 6 65 93 journal article http://doi.org/10.5281/zenodo.4760872 a1bfbb3c-ae2d-46cf-9eb6-16aaf974ea61 1854-0392 4760872 6FA6F27D-DBC8-4F39-8063-8BA3C5508155 Key to the Adults of Extant Nearctic Megaleuctra Males 1 Tip of subanal probe acute or threadlike ( Figs. 21- 22 , 25, 29 , 75 , 77, 81); known distribution Appalachian Mountains region of eastern North America.………………………………….…….… 2 1’ Tip of subanal probe enlarged and bearing a subapical notch ( Figs. 3 , 10 , 16 , 36 , 64, 68); known distribution northern Rocky Mountains , Sierra Nevada and Cascades of western North America ……………………………..……..….... 3 2 Tergum 9 bearing a small, darkly sclerotized, median, toothed process between low lateral lobes ( Figs. 21 , 28 ); subanal probe expanded above base and about mid length, tip thread-like ( Figs. 21, 22 , 25, 29 ); known from Maryland, Pennsylvania, West Virginia and Shenandoah National Park , Virginia ……………..…… M. flinti 2’ Tergum 9 without median process or low lateral lobes ( Figs. 74 , 78); lateral aspect of subanal probe relatively uniform in diameter throughout, tip truncate ( Fig. 75 , 81); known from North and South Carolina, Tennessee and the Mount Rogers area of southwestern Virginia ..….. M. williamsae 3 Tergum 9 bearing large pair of rounded dorsal processes near posterior margin, anterior margin of process rounded, posterior margin angled abruptly downward, lateral profile forming a broad arc ( Figs. 55 , 67), cerci short … M. stigmata 3’ Tergum 9 bearing smaller pair of processes near posterior margin, processes thinner and pointed at apex, cerci long ( Figs.3 , 5 , 36 , 42) ..................… 4 4 Processes on tergum 9 relatively symmetrical, broad basally, narrowed apically and bluntly pointed or conical at tip ( Figs.6 , 13 ), dorsal lobe of subanal probe long, thin and pointed at tip ( Fig. 14 ), epiproct large, bearing large downward directed hooks medially when partially expanded ( Fig. 9 ), hooks extending to apex of subanal probe when fully expanded ( Fig. 8 ), ventral portion forming an elongate triangle when viewed dorsally ( Fig. 6 ) ……………………… M. complicata 4’ Processes on tergum 9 thin, delicate, long and abruptly pointed ( Figs. 36 , 38), distal portion of subanal probe broad, and diamond shaped, with a small thin tip ( Figs. 46-47 ), epiproct extending to near tip of unexpanded subanal probe ( Fig. 42 ), but reaching far short of expanded probe ( Fig. 48 ), thin tips not very conspicuous when expanded ( Figs. 46, 50 ), hooks less obvious when extended to apex of subanal probe, ventral portion forming a stout triangle when viewed dorsally ( Fig. 35 ) ……..……………………….………….… M. kincaidi Females 1 Known distribution Appalachian Mountains region of eastern North America ………….…… 2 1’ Known distribution northern Rocky Mountains , Sierra Nevada and Cascade Mountains of western North America ……………….….……….……… 3 2 Subgenital plate (ovipositor) almost subequal in width from beyond base to apex ( Fig. 83 ), known distribution North and South Carolina, Tennessee and Mount Rogers area of southwestern Virginia ………..…………………..……….…. M . williamsae 2’ Subgenital plate (ovipositor) narrowed conspicuously from base to apex; known from Maryland, Pennsylvania, West Virginia and Shenandoah National Park , Virginia .…… M. flinti 3 Stigma beyond cord large, darkly pigmented and filling most of costal space; usually more than 3 branches of radial sector vein ( Fig. 1 ) .. M. stigmata 3’ Stigma beyond cord small, less darkly pigmented and filling less than half of coastal space; usually 2 or 3 branches of radial sector vein ( Fig. 85 ).……….………..……….... M. complicata / M. kincaidi