560 JOIJRNAl. OF ECOXOMIC ENTOMOLOGY [Vol. 9 



Table III. Duration of the Protonymphal Period 



Period Duration (days) 



July 2 to July 7 5 



July 1 to July 5 4 



Average 4.5 



Deutonymph 

 FoUoAving the molting of the protonymph, which in every respect 

 is quite like that of the larval molt, the appearance of the deutonymph 

 (Fig. 38, a) is very much like that of the earliest nymphal stage. It 

 differs only in the increased size, the slightly deepened color, and the 

 greater reduction in size of the spinous appendages. Table IV presents 

 the results of the two bred deutonymphs. 



Table IV. Duration of the Deutonymphal Period 

 Period Duration (days) 



July 1 to July 5 4 



July 1 to July 5 4 



Average 4 



Generations 

 From the foregoing it will be seen that the development of a genera- 

 tion of privet mites takes place about as follows: 



Days 



Incubation period 8 



Larval period 4.7 



First nymphal period 4.5 



Second nymphal period 4 



2172 



A generation in summer time, therefore, requires about three 

 weeks for completion in the latitude of Batesburg, S. C. It seems 

 probable that in South Carolina there are six or seven generations in 

 the course of a season. This has not been definitely determined, 

 however. 



Longevity 



The rearing of Tenuipalpus was beset with several difficulties such 

 as predators, humidity control, rain, etc. Although an effort was made 

 to simulate natural conditions, entire success was not attained. In 

 spite of this we believe that the conditions surrounding our experi- 

 ments were not sufficiently inimical to greatly influence the results. 

 Of our four experimental females the individual longest under observa- 

 tion lived 17 days within the isolation cell and deposited in that time 18 

 eggs: the next longest record was 14 days in which time 13 eggs were 

 deposited. 



