1909] Life History of Coriziis lateralis Say. 275 



the ocelli have not yet appeared. The body is now almost as 

 large as that of the adult and has the same general appearance. 



There is one character common to all the nymphal stages of 

 this insect except the first, which gives some insight into its 

 phylogeny. This is the banded legs. These are lost in the adult 

 lateralis, but are present in sidae, its tropical relative, which 

 barely reaches our southern borders. This seems to indicate that 

 probably sidae is the progenitor of lateralis and that this change 

 has been the effect of climate. 



While the different stages may vary much in duration that 

 of the sum total of all does not. This is, in all cases observed, 

 from twenty to twenty-one days. 



There yet remains one important fact to be learned in the 

 life history of this insect. It is not known positively how it 

 passes the winter. There can be little doubt, however, that, it 

 hibernates in the adult stage. It is inconceivable that either 

 the eggs or young could endure the winter after their host plant 

 has perished. As before stated, young could be found in all 

 stages until frost, and then all, including the adults disappeared. 

 It is probable that the former were killed while the latter sought 

 shelter among rubbish. 



It was not definitely determined whether the host plant is 

 injured by the attack of this insect or not. There was, however, 

 some indication that such is the case. One colony that harbored 

 an extraordinary number of insects ripened very few seed. 

 Some heads not having more than a half dozen seed that reached 



maturity. 



Many of the eggs coUected failed to hatch. Instead of turn- 

 ing red they soon became almost black and quite opaque. Later, 

 from these eggs small hymenopterous parasites would emerge, 

 whose identity has not yet been determined. 



DESCRIPTION. 



EGG. 



In size, .5 by .7 mm., — oval when viewed from the side but 

 somewhat triangular when viewed from the end. 



Color: Yellowish, pale, turning red before hatching. Attached 

 by slender thread to petioles of host plant in clusters of two to twelve. 



FIRST INSTAR. 



1 mm. in length. Head and thorax prominent, not separated 

 bv constriction. Abdomen small, consisting of nine segments, the 

 fifth of which is interrupted at the middle and two small glands are 



