BUTTERFLIES OF THE DISTRICT OF COLUMBIA 131 



The caterpillars are found in the colonies of woolly aphids on the 

 alder, beech, or other plants, usually living in flimsy silken tunnels 

 underneath the aphids, though the fully grown ones may simply 

 rest uncovered in the aphid mass. They are difficult to detect, but 

 if the aphids be scraped off carefully they are easily discovered. 



Late in the summer of 1931 the beeches along the Northwest Branch 

 at Silver Spring were to a greater extent than usual infested with 

 woolly aphids {Prociphilus imhricata) . On September 19, James A. 

 Hyslop, Foster H. Benjamin, and I found the butterflies common 

 there, and also found many of the caterpillars. Most of the larger 

 caterpillars were lying fully exposed among the aphids, chiefly on 

 the upper side of the twigs, and the small ones were in tunnels. 

 Mr. Benjamin found a few caterpillars in domiciles that had been 

 made by fastening two leaves together with silk. He also found 

 one about to pupate on the underside of a dead leaf on the ground. 



The curious life history of the alder butterfly is given in the papers 

 to which references are given. All of them mention specimens from 

 Washington. 



Subfamily Lycaeninae 



KEY TO THE SPECIES 



o\ Fore wings above coppery red with a brown border and some 

 black spots ; hind wings above dark grayish brown with a red 



submarginal band (pi. 22, figs. 7-10) Chrysophanus phlaeas (p. 131). 



a^ Wings wholly or mostly blue above. 



&\ Hind wings with a threadlike tail near the inner angle ; two 

 bright orange spots at the base of the tail ; above violet 

 blue, or blue more or less extensively suffused with brown 



(pi. 22, figs. 5, 6) Everes comyntas (p. 133). 



6^ No tails on the hind wings; above bright blue or blue and 

 white, sometimes with the fore wings bordered with dark 

 brown (pi. 22, figs. 1-4) Lycaenopsis argiolus (p. 136). 



Genus CHRYSOPHANUS Doubleday 



CHRYSOPHANUS PHLAEAS HYPOPHLAEAS (Boisduval) 



Common Copper 

 Plate 22, Figures 7 to 10 



Occurrence. — Very local and usually infrequent, but occasionally 

 rather common or even abundant in restricted areas. It is to be 

 found in dry and more or less barren localities and about farms 

 wherever the common sorrel {Rumex acetosella) grows. The only 

 places where I have found it are on a dry hillside in Rock Creek 

 Park, at Cabin John, at Silver Spring about a large hayrick and 

 along a dry ditch in an adjacent field, and in fields and on dry hill- 

 sides at Beltsville and Riverdale, Md. Mr. Shoemaker has specimens 



