Mayfly Species Neochoroterpes nanita

This is a dainty brown species with sooty blackish, sinuous cross bands on the dorsum of the whitish abdomen and with ringed tails. Head brown above, paler in front, antennae brown with paler basal segments.

Thorax brown, paler around the leg bases and in the rear of the mesoscutellar hump, and with interrupted hair lines of black on the lower margin of the pleural sclerites. Legs white with only hair lines of black on the anterior face of the femora. Wings white with only a few of the stronger veins brown (especially vein R and its basal connections), there being no color in the wing membrane. Cross veins hyaline and almost invisible even in the stigmatic area.

Abdomen whitish with a double row of broad, diffuse cross-laid ?-shaped sooty black markings separated by a wide middorsal pale line. Segments 9 and 10 darker, especially the side of the 9th sternite. Tails white, distinctly ringed with black, alternate segments more narrowly. Forceps white, penes brown (see fig. 140).

Subimago paler, with faint, smoky-greyish wings and yellowish crown. The rich brown thorax shows a middorsal yellow stripe, narrowed to a hair line at the front, and spear-pointed behind. Conjoined with this toward the rear is an oval line of yellow in the notal furrow, below which the brown of the thorax is darker—almost black—before the wing roots.