Mayfly Species Nixe spinosa

A small species, distinct because of the lateral spines on penes, but evidently related to the lucidipennis (now a synonym of the Nixe lucidipennis) group; mesonotum reddish brown, tergites with a broad median purplish dorsal stripe. Penes as in fig. 98.

Head pale yellow, no distinct markings; ocelli black-ringed at base; bases of antennae white, filament dusky. Thoracic notum dark reddish brown; pronotum purplish brown in median area and center of posterior margin; metanotum darker, with purplish posterior margin and transverse line near center. Pleura and sternum creamy yellowish white, unmarked. Legs pale whitish with a faint yellowish tinge, fore leg more yellow than others; a faint dark stripe on fore femur apically on ventral edge, and femoro-tibial joining pale purplish. Basal joint of fore tarsus 1/3 to 1/4 of second; in hind leg, basal joint distinctly longer than second. Middle and hind femora with faint dark rings at apices. Wings hyaline, all veins colorless.

Abdominal segments 1-7 whitish, semi-hyaline; 8-10 opaque, yellow dorsally, creamy white ventrally. A broad median purplish band on tergites 1-8, the lateral margins remaining widely whitish. Within this dark band is a very narrow pale middorsal line and whitish submedian streaks on each tergite. Posterior margins of tergites 1-8 narrowly dark purple. Median purplish band is lighter posteriorly, on tergites 1-5, then darker to center of tergite. Forceps faintly smoky; penes pale yellow, united and bearing several short spines on the lower lateral margins, as well as the usual two median blunt spines. Forceps long and slender, the two terminal joints together about as long as the second joint. Tails white, with yellowish tinge at base; in basal third, joinings narrowly purplish, pale in remaining portion.

The long terminal joints of the forceps, and the fact that the basal tarsal joint of the hind leg is distinctly longer than the second joint, would seem to ally this species with the lucidipennis group.