“Baltimore Checker-spot” Butterfly 22/ 
Observations on the Lite History of the 
“Baltimore Checker-spot” Butterfly, 
Euphydryas phaeton (Drury), 
in Missouri 
By Harold I. O’Byrne 
Euphydryas phaéton (Drury), named “The Baltimore” many 
hibernation. Although the details of the life history of this 
insect, as it takes place in the neighborhood of Boston, have 
been well told by Scudder,* oheeryaiie ons made in the vicinity 
St. Louis show some interesting differences. 
The essentials of Scudder’s account may be briefly stated. 
The butterflies are seldom found far from the marshy places 
where the food plant, snakehead (Chelone glabra), grows. The 
eggs are laid in clusters on this plant between July 5 and 15, 
and hatch in 19 or 20 days. Each caterpillar devours part of 
small web on its lower surface. They eat only the parenchyma 
covered by this web for a time, then they construct a covering 
web over the topmost leaves of the plant and feed on the en- 
closed leaves. As these are consumed the web is extended, al- 
though individual larvae often leave the web and feed on leaves 
outside. Damage to the web by rain or other causes is repaired 
at once, and the web is continually being improved and strength- 
ened until after the third molt. During this time the droppings 
and shed skins accumulate, and the supporting leaves d 
and turn black, but in spite of its filthiness, the caterpillars con- 
*Scudder, S. H. Everyday Butterflies. Cambridge, 1899. 
