Macrogynoplax duida, Stark, 2011

Stark, Bill P., 2011, Macrogynoplax Duida, A New Species Of Stonefly (Plecoptera: Perlidae) From Cerro Duida, Venezuela, Illiesia 7 (7), pp. 86-88 : 86-87

Macrogynoplax duida sp. n.

( Figs. 1-4 )

Material examined. Holotype ♂, Venezuela, Mt. Duida , November 1928, Ac. 29500, Tate No.? ( AMNH) . Paratype, same site, 29 November 1928, Ac. 29500, Tate No. 406, 1♀ ( AMNH) .

Adult habitus. Biocellate, ocelli small and widely separated. General color pale, pattern obscured by specimen condition. Unpigmented ommatidia on inner margins of eyes absent or obscured by specimen condition.

Male. Forewing length 14 mm. Abdominal apex damaged, paraprocts apparently lacking anteroapical spine; tergum 10 without sensilla basiconica patch, hammer small, circular in outline and apparently oriented horizontally on surface of sternum 9. Apical section of aedeagal tube narrow at base in dorsal aspect and gradually widened to base of subterminal hooks ( Fig. 1 ); lateral margins of tube strongly sclerotized but mesal strip membranous; hooks asymmetrical, curved ventrad; left hook directed dextrally across venter of tube and right hook extending apically toward aedeagal tip ( Fig. 3 ). Aedeagal section beyond bases of hooks bearing a pair of weakly sclerotized, dorsally curved fingerlike lobes and a dorsomesal sclerotized process consisting of a pair of longitudinally oriented blades and a terminal membranous lobe ( Figs. 1-2 ).

Female. Forewing length 15 mm. Abdominal segments 9 and 10 missing. Subgenital plate with subparallel sides and a curved, mesally notched apical margin ( Fig. 4 ); plate covers an estimated 2/3 of sternum 9 (missing) and is almost as wide as sternum 8. Lateral bars not observed due to specimen condition.

Larva. Unknown.

Etymology. The species name, used as a noun in apposition, is based on the type locality.

Diagnosis. The male aedeagus of this species is most similar to that of M. geijskesii Zwick ( Stark & Zwick 1989) among known species, but in that species the aedeagal hooks are symmetrical and the section of the aedeagus distal to the hooks lacks dorsally curved finger-like lobes and a dorsomesal pair of longitudinally oriented blade-like structures. Males key to M. poranga Ribeiro-Ferreira & Froehlich (if the hammer orientation is on the horizontal surface of sternum 9) in the Froehlich (2003) key. However, that orientation is not certain due to specimen condition. The female subgenital plate appears indistinguishable from that of M. pulchra Ribeiro & Froehlich ( Ribeiro & Rafael 2007).

Figures

Figs. 1-4. Macrogynoplax duida genitalic structures. 1. Male aedeagus, dorsal aspect. 2. Male aedeagus, lateral aspect. 3. Male aedeagus, ventral aspect. 4. Female subgenital plate.