of aestivating females lagged considerably behind that of males, showing 
but little ovarian development until raid-November. Segmentation v/as observed 
on November 24 and developing ova on December 7, but none attained the full- 
sized egg stage by December 16, the date of final dissections. It was thus 
indicated that females migrate to fields before attaining complete sexual 
maturity. None of the aestivating females was fertilized, indicating that 
mating does not occur until after migration to fields. 
The initial collection from fields on November 24 of adults recently 
emerged from aestivation revealed some of the females with full-sized eggs 
and fertilized. All field-collected females were fully mature by December 
30 and many were undoubtedly ovipositing. Almost one-third of the males in 
the field were fully mature on November 24 and all were fully mature by 
December 16. It is believed that the full mat-urity of all adults in the 
field indicated that emergence from aestivation was complete. 
Night collections showed that a few adults of the current season 
remained active in the fields until late in June and developed sexually, a 
few males attaining full maturity. Occasional fertilization was attributed 
to the presence of old males, since new ones had not attained full maturity, 
although occasionally one exhibited sperm in the testes. These developing 
adults appeared to be abnormal and exhibited signs of internal discoloration 
and deterioration. Failure to encounter these during the summer and early 
fall, either in fields or in the course of regular dissections, clearly 
indicated that these developing adults die. 
Preoviposition Period 
The preoviposition period of H ypera b runneipennis is equal to the 
length of the aestivation period plus a 2- to 4-week post-aestivation feeding 
and mating period. Calculated in this manner, the preoviposition period is 
8 to 8^ months. 
Oviposition 
Ecological samplings from an alfalfa field on December 12 failed 
to reveal eggs, but oviposition is believed to have begun about December 17, 
the date of initial oviposition in laboratory cages. Oviposition was well 
under way by January 3 and was extremely heavy during January and the first 
half of February. The peak abundance cf F5 eggs per square foot appeared 
on February 5. Thereafter the egg population declined and remained at a 
low level until none were found on or after April 2. It is therefore indi- 
cated that the oviposition period in the alfalfa study field this season was 
approximately 3^ months. 
Similar studies in sourclover were not begun until late in the season, 
but it is unlikely that oviposition began on this host until about mid-Janu- 
ary, since it failed to obtain an appreciable growth before that time. 
Initial studies on March 13 showed 74 eggs per square foot, but thereafter 
