-119- 



conditions, such as too much or too little moisture, or lowered 

 atmospheric temperature. In some cultures in which conditions 

 appeared to be optimal the same phenomenon was observed. The actual 

 frequency of this sort of quiescence was not determined, since, for 

 the sake of efficiency, unhatched egg batches were routinely discarded 

 after 30 days. 



Of 249 gravid females placed in the outside colony, 119 (48%) 

 deposited eggs. The latest date of ovoposition was 16 December. Of 

 the 119 egg batches, 73 (61%) were fertile (had at least one egg 

 hatch), and of those, 33 (45%) showed evidence of diapause. Egg 

 batches contained either 100% fast-developing eggs (nondiapause), 100% 

 slow-developing eggs (diapause), or a mixture of both types, depending 

 on the time of year they were laid (Fig. 3-9). In June and July, all 

 egg batches contained exclusively nondiapause eggs and hatched within 

 5 to 18 days after oviposition. In a batch of 27 eggs laid on the 

 27th of August, 1982, 9 (33%) hatched within 7 days (5 September, 

 1982), one (4%) hatched in 93 days (4 December, 1982), and 4 (15%) 

 hatched in 270 days (26 May, 1983). With the exception of this batch, 

 no diapause eggs were laid before 16 October (18 October, 1982, and 16 

 October, 1983). By November, all egg batches contained at least some 

 diapause eggs and by December, 100% were diapause eggs. At the top of 

 Figure 3-9 are listed the average maximum and minimum temperatures for 

 the months of interest. Duration of the egg stages as a function of 

 month of oviposition is depicted in Figure 3-10. A range of duration 

 of 90 to 270 days was observed for diapause eggs as compared with 5 to 

 27 days for nondiapause eggs. Mean duration of diapause egg stages 

 was 160 days, compared to about ten days for nondiapause eggs. A few 



