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Annals Entomological Society of America [Vol. X, 



From this table we observe that all of the 32 virgin females 

 that were reared from the eggs of the 2 first-generation virgin 

 females laid eggs. Since the breeding cages used up to this time 

 were out-of-door cages these observations give us some insight 

 into the seasonal history of the species. The first adult of 

 the second generation to emerge came out on July 31, the last 

 on August 12. Eggs of the second generation adults were first 

 observed August 9. The first record of a death of the second 

 generation adult was August 9. By August 23 all of the adults 

 of the second generation were dead. The period of longevity 

 appears to be quite short for these second generation adults. 



The progeny of four of these second generation adults was 

 saved, and reared in four separate breeding cages. Some of 

 the data for these four experiments are given in tabular form 

 in the following table. 



TABLE II. 



The results from these four breeding cages were surprising. 

 Of the large number of larvae obtained (109) during the fall only 

 a single adult emerged the following spring. Examinations 

 during the winter showed that most of the larvae had pupated 

 and were alive. Later on I made a very thorough search in 

 the soil for predaceous enemies, but found none that I suspected 

 of preying on the larvae or pupae. In fact the final examination 

 on June 28 showed that the earthen cells were intact. Of the 

 23 earthen cells found on this day, 10 contained the mature 

 dead saw-flies. They had passed through their transformations 

 in good shape, but for some reason did not emerge from their 

 earthen cells. 



Can it be that parthenogenesis when continued into the 

 second generation descendants causes a great diminution in 

 the vitality of the race? 



