March, iQoi.] SeiFERT : LlFE-HlSTORY OF PlATYSENTA VIDENS. 13 



sal, subdorsal and lateral white lines and a broad white stigmatal band. 

 It would be difficult to detect them were it not for this white band. 

 When disturbed they emit, like many other caterpillars, a yellowish 

 brown or greenish juice. At least 75 per cent, of the larv?e follow 

 this type. Another form is chocolate brown with the same lines. 

 Between these two forms a variety of lighter brown shades to olive 

 green are found. The variety in color has nothing to do with the sex 

 or coloration of the imago, neither does the color protect the larvae 

 from the attacks of their parasites, as the dark forms are infested in 

 the same proportion as the normal green form. 



Of the parasites, Protoinicroplitis calliptera Say, is most abundant. 

 This and a dipteron, ]Viiithemia quadripiistulata Fab. , may be seen 

 hovering over the blossoms of the food-plant. As the grubs of the 

 parasites leave the caterpillars before the latter form their cells, the 

 little whitish oval cocoons of the Protomicroplitis may often be found 

 fastened to the leaves and twigs, though as a rule the grubs bury them- 

 selves in the ground deeper than their hosts. Taniscus geminaius 

 Say, is a larger, but far rarer parasite infesting them. 



The larvae and pupae of the moth are hardy and develop easily 

 even when forced by heat, the pupcC of the parasites being more 

 sensitive. The caterpillars do not appear to be much subject to 

 contagious larval diseases — muscardine and flaccidencia — though 

 both diseases are usually most infectious and many larvae of Arctia 

 arge, Arctia na'is, Leucarctia acrcea, Arsilonche albovenosa, etc., are 

 killed by the first named disease and found as stiff, whitish corpses on 

 top of grass blades and stems within and around the habitat of the 

 Flatysenia, while the pretty, adaptive larva of Cucullia asteroides feed- 

 ing frequently on the blossoms of Solidago and Euthamia are often 

 found affected or destroyed by the latter disease. 



The summer-heat quickly develops the moth, the copulation is of 

 short duration and the female at once deposits her eggs singly or not 

 more than six on a leaf. They are not fastened very tightly and may 

 be shaken off by beating. 



The larvae were plentiful in the district alluded to above. Several 

 places in Westchester Co., where E . gramitiifolia grows plentifully {^E. 

 caroliniana is far more local), were carefully searched for the larvae, 

 but none were found. Even virgin females exposed there did not 

 find mates. These localities are mostly boggy or rocky. Common 

 as the moth is, it still seems to be confined to certain conditions and 



