stations, of which five were in S. alterniflora , one in Spartina- 

 Salicornia-Limonium , three in Juncus , three in Distichlis , and two in 

 S. patens . Diptera were most abundant at the other six stations, and 

 were second in abundance in samples from most stations at which Homoptera 

 were predominant. Hemiptera, Orthoptera, Coleoptera, and Hymenoptera 

 were also present at all stations, usually in much smaller numbers. 

 Homoptera decrease, and other orders increase, in abundance as zone 

 elevation increases. 



The specific composition of the insect assemblages of each type of 

 marsh was determined. The zonal distribution, frequencies, and densities 

 of the principal insect species are illustrated in diagrams. Frequencies, 

 densities, field observations, and special collections were used to 

 construct an outline of the characteristic insect species of the summer 

 aspect of each type of marsh. 



Most of the characteristic insect species from all types of marshes 

 are herbivores, and fall into these three categories: (1) those with 

 chewing mouthparts, the most important of which are grasshoppers, feed 

 on plant tissues; (2) those with piercing and sucking mouthparts, the 

 homopterans and most hemipterans, feed on plant sap; (3) those with 

 sponging mouthparts, mainly species of Diptera, feed on plant secretions. 

 The principal carnivores in all types of marshes are spiders. The most 

 abundant carnivorous insects are beetles, asilids, mosquitoes, and 

 reduviids. Detritus-feeding ephydrid and dolichopodid flies are common 

 in S_^ alterniflora , Spartina-Sal icornia-Limonium and Distichlis . 

 Dipterous larvae parasitize salt marsh plants, and the larvae of parasitic 

 hymenopterans undoubtedly infect many species of salt marsh insects. 



There is no evidence that members of any insect species encountered 

 in this study ordinarily allow themselves to be inundated by rising 

 water. Some kinds of salt marsh insects can swim, walk, or hop over 

 the surface film, and others escape high water by flying. The seasonal 

 distribution of the predominant types of insects, as indicated by their 

 presence or absence in samples, is given. Several species of fulgorids 

 and other homopterans, some dipterans, and a lygaeid, occur throughout 

 the year in the adult stage. Orthopterans, beetles, most species of 

 ants, parasitic hymenopterans, most cicadellids, and most kinds of 

 hemipterans and dipterans are absent in winter. (Author's summary) 



Keywords: insects, salt marshes. North Carolina 



V-D-8 



Cameron, G.N. 1972. Analysis of insect trophic diversity in two salt 

 marsh communities. Ecology 53:58-73. 



This study analyzes trophic relationships of the insect component 

 of two intertidal salt marsh communities dominated by Sal i corn i a pacifica 

 and Spartina foliosa, respectively. Seasonality of that component 



256 



