THE PAEASITE SEASONS. 



63 



nation period or winter season and the opening; of the spring season. 

 From March until tlie middle of June or sometimes July there are no 

 cotton squares for the weevils to breed in. Consequently the para- 

 sites are obliged to seek other hosts. The summer season is defined 

 as beginning mtli the production of squares in which the weevils and 

 their parasites may breed. Thus this season continues until squar- 

 ing ceases — that is, until late in the fall when cotton is killed by frost 

 and is succeeded by the winter season. However, we frequently dis- 

 tinguished a fall or postmigration season, which begins with the first 



Fig. 14.— Map showing the distribution of the more important parasites of the boll weevil. (Original.) 



attack of weevils upon the bolls in August and ends with the heavy 

 frosts in October or November. The fall season is also character- 

 ized by a renewed growth of squares, 



I. THE HIBERNATION OR WINTER SEASON. 



The most important parasites which winter as immature stages 

 upon the boll weevil are Microhracon mellitor, Catolaccus hunteri, Ceram- 

 bycohius cyaniceps, Eurytoma tylodermatis, Tetrastichus hunteri, and 

 Hahrocytus piercei. The last two species are characteristic of 

 winter examinations in Louisiana and Mississippi. The predatory 



