I96 UNIVERSITY OF COLORADO STUDIES 



1. Female with a definite sac at maturity, the sac closely felted, like that of Erium 



lichtensioides, insect very pale, with a slight pinkish tinge (Las Vegas, N. M.) 



portera, ckll. 

 Female with no such sac .......... 2 



2. Female with a definite fringe of lateral white tassels ..... 3 

 Female without such a fringe ......... 4 



3. Female light yellow, small; antennae 6-jointed (northern New Mexico; Boulder, 



Colo., found by W. P. Cockerell, Nov. 1904) . . fimbriatula, ckll. & king 



Female salmon-pink, larger; antennae 7-jointed(northern New Mexico and 

 Boulder, Colo.) ........ salmonacea, ckll. 



4. Female very convex, almost hemispherical, bright orange; antennas 6-jointed 



(Las Vegas, N. M.) ........ aurantia, ckll. 



Female of the ordinary shape ......... 5 



5. Female pale green; antennae 7-jointed (Las Vegas, N. M.; and recently found by 



W. P. Cockerell, at Boulder, Colo.) viridula, ckll. 



Female pinkish, yellowish, or whitish ........ 6 



6. Female dark pink, about 2! mm. long; antennae normally 7-jointed (Trout Spring, 



N. M.) ......... magna, t. & w. ckll. 



Female pale pink or pale yellow ......... 7 



7. Antennae 7-jointed (sometimes 6 in flaveola and cockerellce) .... 8 

 Antennae 6-jointed ........... 9 



8. Antennal joints 1 to 6 subequal; legs very slender (Trout Spring, N. M.) tenuipes, ckll. 

 Joints 1 to 3 successively a little longer, or 2 and 3 equal, 4 to 6 obviously shorter 



than 3; legs ordinary; insect yellow (Las Vegas, N. M., with Lasius inter jectus) 



flaveola, ckll- 

 Joint 3 conspicuously shorter than 2 or 4; legs ordinary (Beulah, N. M., 8,000 ft.) 



. cockerellae, king 



9. Longer than usual; caudal bristles very long (165 micromillimeters) ; bristles of 



anal ring long (Las Vegas, N. M.) trichura, ckll- 



Shape ordinary; caudal bristles not especially long ..... 10 



10. Female with antennal joints 1 to 3 about equal; head of male seen from above 



widest in region of eyes, which are black and relatively large (northern New 

 Mexico) .......... triviltata, ckll. 



Female with the third antennal joint obviously longer than second; male with head 

 seen from above broadest behind the eyes, which are small and dark crimson 

 (northern New Mexico, in nests of Lasius americanus and probably this, but 

 young only found, at Boulder, Colo.) .... confusella, ckll. 



Note. — R. arizonensis, Ehrhorn, found in Arizona, is light purplish-brown, and makes 

 a waxy sac. 



The identity of species of Ripersia should be confirmed by measuring the joints of the 

 antennae of adult females. Of course no two antennae will measure exactly alike, but with 

 a reasonable allowance for variation the measurements are very helpful. The following 

 measurements are all in micromillimeters : 



