370 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 25 



Text figure 12 (graph) presents the same information for 5", metalli- 

 cum. The peaks in population of this species are not nearly as well 

 marked as for ochraceum. This substantiated our repeated observa- 

 tions that 5^. metallicum is present in large numbers throughout most 

 of the year, while ochraceum is more cyclical in appearance. However, 

 there is a gradual reduction in adult population from June through 

 December, a sharp drop in May at the beginning of the heavy rains, 



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ADULTS 



_o_d— LARVAE 

 -y-x- PUPAE 



Fig. 

 period, 

 during 



JAN FEB MAR APR MAY JUK JIIL AUO SEP OCT NOV D(C 



II. — Fluctuation in population of 5'. {S.) ochraceum throughout a year 

 expressed as the average number of specimens captured per collection 

 month periods. (Prepared on 3-cycle semilogarithmic paper.) 



and a rise during January through April. The larval population varies 

 accordingly, the maximum larval population coinciding with the low 

 in adult population. Again, the population trend of the pupae more 

 or less approximates that of the adults. 



As for ochraceum, the adult callidum population (graph, text fig. 

 13) is highest during the middle of the dry season (January and 

 February) and reaches a secondary peak in August, during a lull in 

 the rains. The fluctuations in population appear more numerous than 

 for ochraceum or metallicum, indicating the possibility that callidum 

 passes through more generations in a year than do the other two spe- 



