96 



Day: Ephemeroptera 



Fig. 3:20. Structures of Ephemerella. a, cognoto, male geni- 

 talia; b, micheneri, male genitalia; c, species of invaria group, 

 fore leg of nymph; d, tibialis, male genitalia; e, simplex, gills 

 and lateral spines (a,c,e, Day; b,d, Needham, Traver, and Hsu, 

 1935). 



double submedian stripes on venter of abdomen; veins 



of fore wing colorless (fig. 3:20a) 



cognata Traver 1934 



— Ganglionic areas of sternites either wholly dark or 

 showing indications of darkness; veins of fore wing 

 pale or gray brown 2 



2. Abdominal sternites with ganglionic areas only faintly 

 darkened and with no other dark marks present; veins 

 of fore wing pale gray brown (fig. 3:20a 7 ) 



tibialis McDunnough 1924 



— Abdominal sternites with dark ganglionic areas and 

 wide, dark lateral streak near each pleural fold; veins 

 of fore wing pale 3 



3. Fore tibia one-half longer than fore femur (fig. 3:27A) 



". levis Day 1953 



— Fore tibia twice as long as fore femur (fig. 3:206) 



micheneri Traver 1934 



Nymphs 



Maxillary palp minute or absent 2 



Maxillary palp better developed, 3 jointed and normal in 

 form, the total length of the palp being almost equal to 



the width of the body of the maxilla at the point A 

 attachment of the palp j] 



2. Maxillary palp absent; dorsal abdominal spines o| 

 segments 4-7; ganglia of sternites darkened, and a roi 

 of dark lateral dashes (So. Calif.). . .teresa Traver 193l 



— Maxillary palp a minute stub; true dorsal spines oj 

 segments 4-7; ganglia of sternites darkened, and a roij 

 of dark lateral dashes; central California coastal am 

 east slope Sierra Nevada cognata Traver 193J 



3. Dorsal abdominal spines absent (fig. 3:27c); northen 

 California coastal levis Day 1951 



— Dorsal abdominal spines present i 



4. Dorsal abdominal spines present on segments 3-8, bea 

 developed on 4-7; dark markings present on venter o 

 abdomen; widespread micheneri Traver 193 



— Dorsal abdominal spines present on segments 2-9; ru 

 dark markings on venter of abdomen (fig. 3:196); wide 

 spread tibialis McDunnough 192 



Genus Ephemerella Walsh: Walkeri (Fuscata) Group 



Key to the California Species 



Adults 



1. Second joint of male forceps strongly bowed, with i 

 deep constriction near the middle (fig. 3:21a); fori 

 wing length 14 mm.; venation dark brown; abdomina 

 segments brown banded doddsi Needham 192 



— Second joint of forceps not strongly bowed 



2. Second joint of male forceps with a sharp constrictioi 

 near the apex, the tip expanded and bent inward (fig 



3:216); fore wing length 8 mm., venation pale 



flavilinea McDunnough 192 



— Second joint of forceps straight or curved slightl; 

 inward; venation dark brown 



3. Dark brown species; abdomen uniform dark brown excep 

 that margins of segments are pale, as is pleural fold 



fore wing length, 12 mm. (fig. 3:21c) 



coloradensis Dodds 192 



— Reddish or rose-colored species 



4. Species withi head and thorax dark yellow-brown anc 

 abdomen deep ruddy, tergites somewhat lighter in tone 

 fore wing length 18 mm.; wide, creamy line along pleura 

 fold; wide, creamy margins of each segment give 

 abdomen a strongly marked annulate appearance (fig 

 3:2 la 1 ) glacialis carsona Day 195 



— Species with pale yellow head, thorax yellow-brow 

 and abdomen bright purple-rose; fore wing length, 1 

 mm.; wide, white stripe full length of pleural fold 

 tergites 4-10 and all sternites with wide, white posteric 

 margins (fig. 3:21e) spinifera Needham 192 



Fig. 3:21. Male genitalia of Ephemerella, a, doddsi; b, flavilinea; c, coloradensis; d, glacialis 

 carsona; e, spinifera (a, Dodds, 1923; b, Needham, Traver and Hsu, 1935; c, McDunnough, 1929; 

 d,e, Doy, 1952). 



