1204 THE BUTTERFLIES OF NEW ENGLAND. 



scales. In the colder parts of its range, the second i)rood is more like 

 individuals of the first brood farther south, and at the soutliern limits of 

 its range the spring butterflies ai-e far less heavily marked than in the 

 north. In both this species and the next the hind wings of the second 

 generation are longer than those of the first. 



Enemies. ' The only parasite of this butterfly which is known is Apan- 

 teles gloineratus (88 : 12) , whose action, according to Riley, is described by 

 Mrs. C'harlotte Taylor in a popular article in the American Agriculturist 

 for 18fi0. But Gentry says that many birds feed upon it both in the 

 larval and perfect stages and several species feed it in large numbers to 

 their young ; but it is more than doubtful whether he correctly distinguished 

 this species from P. rapae when examining larvae from a bird's stomach. 

 The principal enemies, in his view, are the robin, Merulamigratoria, the 

 wood robin, Turdus mustelinus, the bluebird, Sialia sialis, the redstart, 

 Setophaga ruticilla, the chipping sparrow, Spizella socialis, the great crested 

 fly-catcher, Myiarehus crinitus, the king-bird, Tyrannus tyrannus, and the 

 nisrht hawk, Chordelles virginianus. 



Desiderata. The relation of this butterfly to P. rapae, the foe of its 

 own household which has arisen in these latter days, is an important one. 

 Undoubtedly its decimation has been related in some way to food supply, 

 and a study of the relation of the two species to other plants than cabbage, 

 especially if they be indigenous, would be interesting. Is there any in- 

 dication, where the two occur, that the broods of oleracea are beginning to 

 appear earlier than formerly, in order the better to compete with rapae which 

 has now first choice of plants ; very careful observations in uncultivated ter- 

 ritory for a score of years would be needed to settle such a point. What is 

 the cause of the relative poverty of the second brood. Do any of the 

 June chrysalids persist, to swell the third brood of butterflies? Do the 

 occasional members of a fourth brood ever lay eggs, and if so, can the 

 caterpillars from them ever go forward to chrysalis ? The line separating 

 digoneutism from polygoneutism should be made out. With the over- 

 balance of rapae it would now perhaps be impossible to determine whether 

 in the southern Alleghanies the form virginlcnsis lias other broods the same 

 season, which Mr. Edwards denies, but which it is difficult not to believe. 



LIST OF JLLUSTRATIONS.-PIEBIS OLERAOEA. 



General. Chrysalis. 



PI. 26, fig. 5. Distribution in North America. PI. 84, fig. 57. Side view. 

 88:12. Apauteles glomeratus; a para- 63-64. Outlines, 



site. Imago. 



Egg. PI. 7, fig. 3. P. o. cruciferaruni, ? , both sur- 

 Pl. 65, fig. 27. Plain. faces. 



68:15. Micropyle. 13:2. Upper surface. 



Caterpillar, 35:15,16. Male abdominal appendages. 



PI. 76, figs. 8, 9. Full grown caterpillar. 40:7. Neuration. 



79 : 50-52. Head, first stages, i, iii, v. 46: 39. Androconium. 



86:32. Mandible of caterpillar at birth, 56:6. Side view, with head and appen- 



44. Dermal appendage, first stage. ' dages enlarged, and details of leg structure. 



