Lednia (Ricker) 1952

Baumann, Richard W. & Kondratieff, Boris C., 2010, The Stonefly Genus Lednia In North America (Plecoptera: Nemouridae), Illiesia 6 (25), pp. 315-327 : 316

Lednia (Ricker) 1952

Lednia Ricker, 1952: 29 . Type species: Nemoura (Lednia) tumana (Ricker) , by monotypy. Illies, 1966: 190 (generic status). Baumann, 1975: 19, 50 (redescription and illustrations). Baumann et al. 1977: 34 (distribution).

DESCRIPTION

Adult. Size small, length 4.5-7.5 mm. Wings macropterous, venation typical for family, mostly hyaline, with dark veins near cord. Gills absent.

Male. Epiproct with ventral sclerite sclerotized, flat, broad and pointed at apex, extending beyond anterior margin of dorsal sclerite, bearing few small ventrolateral spines near apex, tip sharply pointed and grooved dorsally; dorsal sclerite grooved mesally and bilaterally symmetrical, bearing small to large posteriorly directed dorsolateral spines ( Figs. 1- 3 , 5-6, 8-9, 13, 15-18, 23, 25-28). Paraprocts composed of two lobes, inner lobe long and thin and heavily sclerotized, with sharply pointed apex ( Figs. 11 , 19 , 29 ); outer lobes, short broadly rounded and lightly sclerotized ( Fig. 20 ). Hypoproct broad at base and becoming narrower towards apex, vesicle absent ( Figs. 11 , 19 , 29 ). Cerci unmodified ( Figs. 1, 3 , 5, 8, 15, 25, 29). Tergum ten with median groove, bordered by paired mace-shaped prongs bordering tip of epiproct ( Figs. 1, 3 , 8, 10, 16, 21, 30).

Female. Sternum eight modified as subgenital plate, median area darkly sclerotized, broad basally and narrowing to apex, forming a generally triangular shape, apex narrowly rounded apically, but sometimes with a narrow slit at tip, lateral posterior margins with darkly sclerotized lobes that parallel the apex of subgenital plate ( Figs. 4 , 12, 14, 22, 24, 31, 32). Sternum seven with lightly sclerotized, round lobe near margin of sternum eight ( Figs. 4 , 12, 14, 24, 31).

Larva. Gills absent. Pronotum elongate, with narrow lateral discs. Body of nymph with relatively few spines present, most spines found dorsally at anterior margins of thoracic segments and anterior abdominal segments. Legs bearing few, mostly small spines, except for 3-5 larger spines that occur on dorsal margin of femur. Cerci with whorls of spines at distal margins of segments. Few small intercalary spinules present on all segments. Mature female larvae exhibiting a vesicle-like lobe on sternum eight. For a more complete description see Stewart and Stark (2002).

Figures

Figs. 1-3. Lednia tumana male genitalia: 1. Dorsal. 2. epiproct, dorsal. 3. lateral. Fig. 4. Lednia tumana female terminalia, ventral.

Figs.5-11. Lednia tumana male genitalia: 5. terminalia, dorsal. 6. epiproct, dorsal. 7. epiproct apex, dorsal. 8. terminalia, lateral. 9. epiproct, lateral. 10. prong on tergum 10. 11. terminalia, ventral. 12. female terminalia, ventral.

Figs. 15-21.Lednia borealis male genitalia: 15. terminalia, dorsal. 16. epiproct, dorsal. 17. epiproct, dorsal.18. epiproct, lateral. 19. terminalia, ventral. 20. right paraproct. 21. prong on tergum 10. 22. female terminalia, ventral.

Figs.25-30.Lednia sierra male genitalia: 25. terminalia, dorsal.26. epiproct, dorsal.27.epiproct apex, dorsal.28.epiproct, lateral.29. terminalia, ventral. 30. prong on tergum 10. 31.female terminalia, ventral.32. female subgenital plate, ventral.