IIESPERmi: EPARGYREUS TITYRUS. 1411 



and tlie divergence varies from 90" to 120". When walking, the wings 

 are held as after settling, and the antennae diverge at right angles, the 

 clul> turned a little outward. 



Enemies. In 1848 Dr. Harris i)rcd Ophion bilineatus (88:8) from 

 this insect ; it stings the caterpillar and makes its exit from the chrysalis 

 late in June. Riley has taken Pteromalus puparum (89 : 1-2) in the act 

 of laying its eggs on the caterpillar, and I have found a nest occupied by 

 the cocoon of another hymenopterous parasite of medium size, probably a 

 Lininei"ia, Mr. Howard tliinks, which left the caterpillar nothing but skin 

 and head in its penultimate stage ; according to Harris it is also attacked 

 by a dipterous parasite, a species of Acroglossa, to which he gave the 

 name of Tachina hesperidarum ; it was bred by him from the chrysalis in 

 spring and specimens, considered by him the same, were taken on thistles 

 July 22 by Rev. Mr. Leonard, of Dublin, N. H. Gentry says that the 

 white-cvcd Vireo, Vireo noveboracensis, feeds upon the perfect insect. 



Desiderata. The principal point requiring investigation in the history 

 of this insect is the number of broods in the New England states. Is 

 there always a second brood ? and is there possibly a third in the south ? 

 It has been claimed that forms found in the extreme south, and until 

 recently regarded as distinct, should be looked on as at most varieties of 

 this species, and therefore the earlier stages of both forms in the south 

 should be carefully compared. The egg is insufficiently described. This 

 common species would be the best to study in trying to learn the office of 

 the ranged crateriform annuli of the caterpillars of Hesperidae. 



LIST OF ILLUSTRATIONS.— EPARGYREUS TITYRUS. 



General. PI. 87, fig. 1. Cremaster and cremastral hook. 



PI. 27, fig. 5. Distribution in North America. 11. Side view of front end, showing 



88:8. Ophion biliueatus, a parasite. thoracic spiracle. 



89 : 1. Pteromalus puparum. $ , a parasite. 12. Cocoon and chrysalis. 



2. Same, 9. Imago. 



Caterpillar. PI. 9, fig. 8. Male, both surfaces, colored. 



PI. 73, fig. 8. Caterpillar at birth. 15:3. Both surfaces. 



76:30,31,33. Mature caterpillars. 35:36. Male abdominal appendages. 



35. Caterpillar, third stage. 41:2. Neuration. 



80: 19-22. Frontviewsofhead,stagesi,iii-v. 47:11. Scales of male imago. 



82:11. Nest. 58:1. Side view of head and appendages 



Chnsalis. enlarged, with details of the structure of 



PI. 82, fig. 9. Cocoon. ^^^ 'egs. 



85:22,25,26. Chrysalis, side views. 61 : U. Front view of head, denuded. 

 86 : 26. Shrouds for the attachment of the 

 cremastral hooks. 



