54 PRIZE ESSAY 



(VlG.g.) VW \— -/ (FIG. J.) 



(FIG. 7i.) (FIG.i.) 



DOESAL VIEW OF THE DORMANT LAEVA TAKEN FEOM THE LARVA CASE. 



g. Magnified dorsal view of the worm or active larva, h. Magnified view of the 

 ' flax seed ' or larva case. i. Magnified ventral view of the same. j. Magnified 

 lateral view of the same. 



87. At the advent of spring the dormant larva assumes the 

 pupa or chrysalis state, still remaining vnthin its now pupa case, 

 which has become quite brittle, " breaking asunder tranversely 

 if rudely handled, and one of its ends slipping off from the en- 



f closed pupa, like a thimble from the end of the 

 finger." (1) Fig. 1 shows the pupa removed from its 

 pupa case, and magnified like the preceding illustra- 

 FiG. 1. tions. 



88. After remaining in this condition for ten days or a fort- 

 night it wriggles out of its case, works its way up to light and 

 air, emerges through its cracked pupa skin, and takes the form 

 of the fly, to live its short life ten days or more. Dr. Fitch 

 thinks that in all parts of the United States the Hessian fly will 

 probably be found in its fully formed pupa state, about a week 

 after the liverwort, (Hepatica triloba), the trailing arbutus, 

 (Epigsea repens), and the red or swamp maple first appear in 

 bloom, and simultaneously with the flowering of the dry straw- 

 berry (Comaropsis Fragarioides), the common five-finger (Po- 

 tentilla Canadensis), the hill-side violet (Viola Ovata). 



89. The wonderful adaptation exhibited during the winter 

 sleeps of the larvse of the Hessian fly in its larvae case, to resist 

 atmospheric influences, such as great extremes of temperature, 

 moisture and drought, throughout the winter months, is perhaps 



(1) Dr. Fitch. 



