Stonefly Species Megaleuctra williamsae (Tiny Winter Blacks)

Source: The Genus Megaleuctra Neave (Plecoptera: Leuctridae) In North America

Male. Macropterous. Length of forewing 14 - 15 mm; body length 11 - 13 mm. General color light brown. Wings hyaline, with dark stigma occupying more than half the costal space beyond the cord. Radial sector of forewing with two branches. Tergum 9 without large lobe-like processes (Figs. 75, 78); subgenital plate tongue-like, apex slightly emarginated (Figs. 75, 79); vesicle at base sternum 9 short, and narrow (Fig. 75). Tergum 10 without ventrobasal expansion (Fig. 79). Epiproct short, forming a right angle at base in lateral aspect (Figs. 75, 78, 80, 82), broad at base, with middorsal groove and upturned hooks at apex (Figs. 75, 82). Subanal probe very long, cylindrical, directed upward and forward, usually fitting in middorsal groove of epiproct (Figs. 74, 77, 82), apex tapered, slightly truncate at tip (Figs. 75, 81, 82); cerci consist of a greatly elongate single segment (Figs. 75, 77, 78).

Female. Macropterous. Length of forewing 12 - 16 mm; body length 12 - 15 mm. Coloration similar to male. Head oval and somewhat flattened. Pronotum elongate, anterior corners squared off, posterior angles with large inward directed bevels (Fig. 73). Radial sector of forewing with two branches. Sternum 8 formed to an ovipositor-like structure, with subgenital plate extending past tip of abdomen (Figs. 76, 83, 84), broadly rounded from beyond the base to almost the apex (Figs. 76, 83, 84); narrowing to short tip (Fig. 84). Sternum 9 long and very thin (Fig. 84). Cerci inconspicuous (Figs. 76, 83).