is determined and influence of physical microenvironmental factors 

 on trophic diversity is assessed. Adult insect populations were 

 monitored weekly, trophic diversity was computed, and relationships 

 with primary production and litter accumulation were quantified. 



Temporal diversity trends were similar in both communities although 

 the amplitude was slightly greater in Salicornia . In both communities, 

 herbivore diversity was highest during the spring months while saprovore 

 diversity was highest during midwinter. Predator diversity responded to 

 both herbivore and saprovore diversity, although it was more closely 

 tied to herbivore fluctuations in Sal icornia . Standing crop biomass 

 was maximum during October and litter accumulation was highest during 

 January. 



Two classes of adult insects occurred: persistent species, repre- 

 senting a low percentage of the total species compliment, were present 

 as adults throughout the year in both marsh communities; seasonal 

 species, on the other hand, were present as adults only during the 

 growing season. 



Seasonal succession in species of herbivores and saprovores reflected 

 productional and transformational changes in plant matter; predators 

 responded likewise, but more impressive was the numerical response to 

 prey populations by particular predators. Correlations were high be- 

 tween each trophic group and its respective resource. 



Physical microenvironmental factors, especially temperature and vapor 

 pressure deficit, seemed to be important in cuing larval development, 

 but did not exert a dramatic effect on adult diversity trends. 



Several strategies of habitat utilization are considered. It is hy- 

 pothesized that the persistent and seasonal species have evolved as 

 specialists to avoid competitive interactions and maximize resource 

 utilization. During annual expansion of resource states, the salt 

 marsh insect component undergoes "species packing" wherein additional 

 species enter the system temporarily to utilize the expanded resource 

 base. 



The study indicated that trophic diversity in both salt marsh communities 

 has distinct seasonal patterns. Biological, rather than physical, 

 factors play an important role in the distinction, although some 

 physical factors are influential. The study further showed that there 

 is a positive correlation between herbivore diversity and standing crop 

 biomass, between saprovore diversity and litter accumulation, and 

 between predator diversity and herbivore prey diversity. Predaceous 

 insects in the salt marsh respond numerically to prey abundance, 

 suggesting that they are host-specific. The host-specificity and lack 

 of diversity of predaceous insects suggest the importance of other 

 herbivore and saprovore predators. 



257 



