Mayfly Species Ironodes californicus

Very similar to Ironodes nitidus; thoracic notum darker, more distinct dark markings on pleura.

Head light red-brown. Thorax pale brownish, according to original description. Specimens in our collection, determined by Dr. Banks as being of this species, have the notum and sternum distinctly red-brown, pleura paler. Quite distinct narrow black markings on pleura anterior to fore wing, above and anterior to middle and hind legs; coxae black-margined, with an oblique black streak across each; trochanters black-tipped. Depressions on each side of scutella dark brown. Legs light red-brown. Outer margins of femora narrowly darker brown; apex of fore tibia, tarsal joinings and claws dark brown. Wings hyaline, venation red-brown, somewhat more distinct than in I. nitidus; cross veins likewise more numerous than in that species. Tendency for costal and subcostal cross veins to be slightly heavier than others. Humeral cross vein, and extreme base of longitudinal veins of costal border, reddish. Stigmatic area faintly brown-tinged; remainder of costal margin even more faintly tinged with same color. 9-10 basal costal cross veins; 4 to 5 between bulla and stigma; about 14 in stigmatic area, most of these simple and distinctly aslant.

Abdominal segments 2-7 semi-hyaline, yellow-brown; posterior margins opaque, blackish on dorsal part of tergites. Tracheae faintly outlined in grey. Segments 8-10 opaque, reddish brown. Tails red-brown, somewhat darker basally. Penes as in fig. 108; small ventral spines somewhat more numerous than in I. nitidus. Second joint of forceps more strongly bowed near apex, and relatively somewhat longer than in nitidus.

This species is closely allied to nitidus, but is apparently distinguished from it as indicated above.

Nymphs taken in Mill Creek Canyon near Redlands, Calif., on May 19, 1932 (C. H. Abbott) maybe of this species. Body dark red-brown dorsally, not as blackish as in Ironodes flavipennis; similar thoracic markings, also zigzag lateral line on the pronotum. Legs somewhat paler red-brown; femoral markings as in flavipennis; apical third of tarsus distinctly darker than other portions of legs. Markings on abdominal tergite as in flavipennis. Ventral markings also very similar, but in addition an oblique dark lateral line from anterior to posterior margin, on each division of thoracic sternum. Gills somewhat paler than in I. flavipennis, deep smoky with purplish tinge; tracheae distinct.