Mayfly Species Siphloplecton interlineatum (Pseudo-Gray Drakes)

A paler species than Siphloplecton basale; a black line below the radius at the bulla in the fore wing; cross veins in fore wing, other than the costals and discal veins, pale.

Eyes of live insect pearly white. Thorax blackish brown; prosternum often considerably marked with white; a broad conspicuous transverse whitish band between the hind coxae. Fore legs pale brown; the basal half of each femur may be brown; middle and hind legs paler. All femora with a broad dark band near the apex; tibiae darker at bases and tips; all tarsal joinings darker. Wings hyaline; cross veins of the costal margin and the disc fuscous, as are also the three longitudinal veins of the costal margin. All other veins of fore wing hyaline. A small brown spot is present at the fork of the hind branch of the radial sector, and sometimes a small cloud near the tip of the costa. The brown areas at the wing bases are more restricted than in basale; these are lacking in the female.

Abdominal tergites 1-5 whitish hyaline, the posterior margins and an oval spot on each side of the median line piceous, the dorsum slightly tinged with the same color. Apical tergites piceous, with lateral whitish areas. Sternites whitish hyaline. Tails whitish, the joinings fuscous; alternate joinings wider.

Dr. McDunnough says of it, “From basale the species is distinguished by the paler abdomen and more restricted brown shading at the base of the wings in the male sex; the cross veins are pale except in the costal and subcostal regions and along the basal portion of the median vein.”