1506 THE BUTTERFLIES OF NEW ENGLAND. 



range, have mentioned it later than June ; whence it would appear that it 

 is single brooded in the north. It appears on the wing very early in May, 

 being nearly or quite as early as T. persius and Miss Guild even records 

 taking it on April 27 at Walpole, Mass. It generally becomes abundant 

 by the 10th of this month and undoubtedly continues to emerge from the 

 chrysalis until the end of the third week and remains on the wing until 

 the middle of June or later, and in northern localities, such as northern 

 New England, imtil near the middle of July. The eggs are probably laid 

 by the middle of May ; they hatch in less than nine days and the caterpillar 

 when full fed prepares for the winter, which it passes in this condition, 

 changing to chrysalis early in the spring. 



I once carried a pair through the winter, one in the cold-storage ware- 

 house in Boston, where the thermometer was kept at a uniform temperature 

 of about 35° ; it was brought out on ^lay 23d and kept at first in a cool 

 place but two days later into an ordinary unheated room ; it went into 

 chrysalis about June 7, and emerged June 20 ; the other was wintered in 

 the cellar and it went into chrysalis about June 2, but gave out a parasite. 



Parasites. The above is the only instance known, the parasite being 

 dipterous, Exorista blanda var. proserpina. It made its mahogany pupa- 

 riuni June 11 and emerged June 25. 



Desiderata. Considering that Abbot painted figures of the catei'pillar 

 and chrysalis of this insect nearly a century ago, and that it is a common 

 butterfly over a very wide territory, it is not creditable that we know scarcely 

 more about it than what Abbot has given us. The early stages are quite 

 insufficiently known, the food plants of the caterpillar to some extent doubt- 

 ful, its habits undescribed as well as those of the butterfly. No hymenoj)te- 

 rous parasites are known and the distribution of the insect in its northern 

 and western range is very uncertain. Is it an insect of the low country, 

 that though found from Atlantic to Pacific it has so rarely been noted in 

 the elevated plateau region ? Is there ever a second brood in the north ? 

 Is there always one at the south ? 



LIST OF ILLUSTRATIONS.— THANAOS BlilZO. 



General. Im ago. 



PI. 28, fig. 4. Distribution in North America. PI. 9, fig. 3. Male, both surfaces. 



Egg. 9. Female, upper surface. 



PI. 66, fig. 12. Egg. 13:17. Both surfaces. 



69:4. Micropyle. 36:7-12. Male abdominal appendages. 



Caterpillar. 45:2. Cross section of costal fold. 

 PI. 77, figs. 12, 18. Mature caterpillar. 3. The same, opened. 



Chrysalis. 47 : 7. Scales of the male imago. 

 PI. 85, fig. 38. Chrysalis. 



