Megaleuctra kincaidi Frison, 1942

Baumann, Richard W. & Stark, Bill P., 2013, The Genus Megaleuctra Neave (Plecoptera: Leuctridae) In North America, Illiesia 9 (6), pp. 65-93 : 77-78

Megaleuctra kincaidi Frison

( Figs. 35-53 )

Megaleuctra kincaidi Frison 1942:15 .

Holotype ♂ ( INHS). Type locality: Fryingpan Creek, Mount Rainier National Park (Pierce Co.), Washington, examined

Material examined. IDAHO: Clearwater Co. Lolo Pass, 30 June 1964, W.F. Barr, 1♂, 1♀ ( BYUC). Idaho Co., Cow Creek, New Elk Summit Road , 27 May 1972, D.S. Potter, R.A. Haick, L. Lockwood, 1♀ ( BYUC). Latah Co. , Big Sand Creek , Saint Joe National Forest , 2880’, 21 May 1975, J.H. Baker, 1♂, 1♀ ( USNM). MONTANA: Missoula Co. , Seep , Granite Creek , tributary Lolo Creek , 46.74° N 114.59° W, 25 June 2013, Z.J. Crete, 1♀ ( ZCSC). Ravalli Co. , Inlet to Bryan Lake , 6800’, 17 July 1995, A.L. Sheldon, 1♀ ( BYUC). Left intermittent tributary Lick Creek , 4760’, 25 May 1996, A.L. Sheldon, 1♂ ( BYUC). Intermittent right fork, left tributary Lick Creek , 4800’, 25 May 1996, A.L. Sheldon, 2♂, 2♀ ( BYUC). Roaring Lion Creek , at road head, 18 March 1996, A.L. Sheldon, 2♂, 2♀ ( BYUC). OREGON: Clackamas Co. , Seep, Still Creek , Still Creek Campground, Mount Hood National Forest , 5 June 1991, R.W. Baumann, B.P. Stark, C. Henderson, 7♂, 2♀, 3 larvae ( BPSC, BYUC). Same site, 2 June 2000, B.P. Stark, I. Sivec, M.C. Zúñiga, 3♂, 1♀ ( BPSC, BYUC). Clatsop Co. , East Fork Humbug Creek , 3 May 1964, S.G. Jewett, Jr., 1♂ ( CASC). WASHINGTON: Kittatis Co. , Bell Creek , Cle Elum Lake , 22 May 1946, S.G. Jewett, Jr., 1♂ ( OSUC). Pierce Co. , Fryingpan Creek , Mount Rainier National Park , 5000’, 23 July 1937, W.E. Ricker, 1♂, Holotype ( CUIC). Ghost Lake , 1 km. N jct. Hwys 123 & 410, 46°52’25” N 121°32’23” W, 6 July 2004, M. Grove, 1♂ ( CSUC).

In addition, Frison (1942) lists two male paratypes from the following localities that were not examined by us: Oregon, between St. Helens and Veronia, 17 April 1937, Gray and Schuh, 1♂, and Washington, Seattle, 14 April 1932, unknown collector, listed by Hoppe (1938) as M. stigmata .

Male. Macropterous. Length of forewing 12-15 mm; body length 12-14 mm. General color brown. Wings hyaline, with dark pigment occupying less than half the costal space beyond the cord. Radial sector of forewing usually with two or three branches. Tergum 9 with a pair of long thin lobes, narrowing to a pointed tip, without basal forked process ( Figs. 35, 36 , 38, 42, 48); subgenital plate tongue-like, apex narrowly rounded ( Fig. 44 ); ventral lobe at base sternum 9 in lateral view subparallel, apex rounded. Tergum 10 with ventrobasal expansion short, sclerotized, bearing paired narrowly pointed processes ( Figs. 36 , 40, 51). Epiproct broadly triangular dorsally when expanded, formed into two sclerotized plates lateral of middorsal groove ( Figs. 35 , 38, 39), when basal, divided into two plates, each ending in pointed apical processes ( Figs. 46, 50 ). Subanal probe directed upward fitting in middorsal groove of epiproct, tip expanded with subapical notch in lateral view, forming two lobes: upper lobe broader at base and narrowing to apex, bearing tube, lower lobe terminating in broad, rounded groove, which surrounds the tube ( Figs. 38-43 , 47- 49 ), cerci formed into an elongate single segment ( Figs. 36 , 42).

Female. Macropterous. Length of forewing 16-18 mm; body length 19-20 mm. Coloration similar to male. Radial sector of forewing with two branches. Sternum 8 with subgenital plate extending past tip of abdomen 1.5-2.0 mm, narrowing gradually to tip, round in cross section ( Fig. 37 ). Sternum 9 a developed ovipositor ( Fig. 52 ); cerci inconspicuous ( Fig. 37 ).

Larva. Described by Stewart and Stark (2002) from unassociated material.

Egg. Undescribed.

Diagnosis. Males of M. kincaidi can be distinguished from M. complicata and M. stigmata by the shape of the paired processes on tergum 9. They are narrow and very thin, ending in a pointed tip in M. kincaidi ( Figs. 42 , 48 ) while in M. complicata ( Figs. 3 , 6 , 13 ) and M. stigmata Figs. 54, 55 , 61, 67, 69) they are broader basally and terminate in a rounded or slanted tip. In addition, the epiproct is triangular dorsally and bears small pointed processes on each side in M. kincaidi ( Figs. 36 , 38, 40, 46), while it is elongate and broad with large paired backward directed hooks apically in M. complicata ( Figs. 3 , 6-9 , 13, 15, 17 ) and in M. stigmata it is parallel and even more elongate, bearing ornamented lateral fringes terminally, and sharp, angular, backward directed prongs apically ( Figs. 57, 58, 61, 62 , 65, 67 ). The female of M. kincaidi may be provisionally distinguished from M. complicata by the presence in the forewing of usually only 2 radial sector branches (typically 3 in M. complicata and 5 in M. stigmata , however, all three species are variable in this character). Associated males should be examined to confirm identifications.

Figures

Figs. 35-37. Megaleuctra kincaidi, Lolo Pass, Idaho. Terminalia: 35. Male, dorsal. 36. Male, lateral. 37. Female, lateral.

Figs. 38-45. Megaleuctra kincaidi, Still Creek, Oregon. Male: 38. Genitalia, dorsal, showing 10th tergal lobes. 39. Genitalia, dorsal, epiproct, extended. 40. Genitalia, lateral, epiproct, extended. 41. Subanal probe, apex, lateral. 42. Genitalia, lateral. 43. Subanal probe, apex, dorsolateral, showing sperm tube. 44. Genitalia, ventral. 45. Subanal probe, seated on epiproct.

Figs. 46-53. Megaleuctra kincaidi. Still Creek, Oregon. Male: 46. Genitalia, dorsal, epiproct, midlength. 47. Subanal probe apex, dorsal. 48. Genitalia, lateral, epipiproct. midlength. 49. Subanal probe, apex, lateral. 50. Epiproct, midlength, dorsal, close up. 51. Genitalia, anterior. Female: 52. Genitalia, lateral. 53. Genitalia, terminal.

Figs. 2-4. Megaleuctra complicata, Still Creek, Oregon. Terminalia: 2. Male, dorsal. 3. Male, lateral. 4. Female, lateral.

Figs. 5-12. Megaleuctra complicata, Willis Creek, Oregon. Male: 5. Genitalia, lateral, open. 6. Genitalia, dorsal, open. 7. Genitalia, lateral, epiproct, extended. 8. Genitalia, apex, lateral, closed. 9. Subanal probe, apex, ventral. 10. Subanal probe, apex, lateral. 11. Vesicle, ventral. Female, 12. Genitalia, ventral.

Figs. 13-20. Megaleuctra complicata, Still Creek, Oregon. Male: 13. Genitalia, dorsal, epiproct, midlength. 14. Subanal probe, apex, dorsal. 15. Genitalia, lateral, epiproct, midlength. 16. Subanal probe, apex, lateral. 17. Genitalia, anterior, epiproct, midlength. 18. Genitalia, ventral. Female: 19. Genitalia, ventral. 20. Genitalia, lateral.

Figs. 54-56. Megaleuctra stigmata. Butler Creek, Montana. Terminalia: 54. Male, dorsal. 55. Male, lateral. 56. Female, lateral.

Figs. 57-64. Megaleuctra stigmata. Bendorf Spring, California. Male: 57. Genitalia, dorsal, epiproct, extended. 58. Epiproct, apex, dorsal. 59. Genitalia, dorsal, base. 60. Subanal probe, apex, anterior. 61. Genitalia, lateral, epiproct, extended. 62. Epiproct, expanded, enclosing subanal probe. 63. Subanal probe and epiproct, lateral, separated. 64. Subanal probe, apex, lateral.

Figs. 65-72. Megaleuctra stigmata. Gray Creek, British Columbia. Male: 65. Genitalia, dorsal, epiproct, midlength. 66. Subanal probe, apex, dorsal. 67. Genitalia, lateral, epiproct, midlength. 68. Subanal probe, apex, lateral. 69. Genitalia, anterior. 70. Genitalia, ventral. Female: Bendorf Spring, California. 71. Genitalia, lateral. 72. Genitalia, ventrolateral.