Doering: Lepyronia quadrangularis. 



523 



Tliird-instar nymphs lived from — 



June 3 to Juno 9 6 days 



May 24 to June 5 12 days 



May 28 to June 8 11 days 



May 25 to May 31 6 days 



May 22 to May 29 7 days 



May 27 to June 6 10 days 



May 25 to June 1 7 days 



May 26 to June 3 8 days 



May 29 to June 6 8 days 



Mav 21 to May 30 9 davs 



May 31 to June 13 13 days 



May 27 to June 4 8 days 



June 30 to July 6 6 days 



These are also counted from molt to molt, 

 six to thirteen. The average is eight. 

 The fourth stage lasted from — 



May 31 to June 8 8 days 



June 6 to July 1 25 days 



June 1 to June 11 10 days 



June 3 to June 12 9 days 



June 6 to June 16 10 days 



May 30 to June 9 10 days 



June 9 to June 18 9 davs 



The range is from 



June 5 to June 14 9 days 



•June 13 to July 7 24 days 



May 31 to June 12 12 days 



June 5 to June 13 8 days 



June 6 to June 13 7 daj's 



June 8 to June 14 6 days 



June 1 to June 25 24 days 



The range is from six to twenty-five and the average is between 



nine and ten. 



The fifth stage lasted from — 



June 8 to June 19 11 days 



June 1 to July 15 14 days 



June 11 to June 26 15 days 



June 12 to June 28 16 days 



June 16 to July 8 22 days 



June 9 to June 23 14 days 



June 18 to June 29 11 days 



June 14 to June 24 10 days 



July 7 to July 20 13 days 



June 12 to June 30 18 days 



June 14 to June 25 11 days 



June 25 to July 9 14 daj'-s 



The range is from ten to twenty-two and the average between 

 eleven and fifteen. 



The seven complete histories from first instar to adult are as 

 follows : 



Number. 



1 



2 



3 



4 



5 



6. 



7 



From the foregoing data it is apparent that there is a wide varia- 

 tion in the length of any stage, which is probably due to the nature 

 and condition of the food plant and the abundance of the sap. 



Field observations also show a wide variation in the length of the 

 stages. In 1922 the first-instar nymphs were taken on April 29 and 



