behavior may differ depending on activity 

 levels' when inactive, they may cling to 

 vegetation when the tide rises to avoid 

 being swept away, but when active, they 

 may move to higher levels in the canopy to 

 reduce oxygen stress. His study does not 

 solve the mystery of the respiration 

 problem, but it points to another 

 difficulty of the tidal environment, 

 namely removal by water circulation. 

 Foster and Treherne (1976) suggested that 

 water flow sometimes may be advantageous, 

 by providing an effective means of 

 small-scale dispersal for insects which, 

 if they were to rely on flight, might be 

 blown to unfavorable habitats outside the 

 marsh . 



within 146 families. Surveys of the 

 entire insect fauna of a locality are 

 always restricted by the difficulty in 

 capturing all species present. Many 

 require the use of special collecting 

 techniques, such as ultraviolet light 

 traps, yellow pan traps, pitfall traps, 

 and berlese funnels. Studies which use 

 nets in vegetation canopies will collect 

 only a fraction of the fauna. At Ballona 

 Creek, many rare species were obtained 

 only in special devices. A new genus of 

 wasp appeared in a yellow pan trap, and a 

 springtail ( Onychiuris debilis ; 

 Collembola: Onychiuridae) , known only 

 from France and Alaska, was collected with 

 a berlese funnel (Nagano, pers. comm.). 



Like the plants which inhabit 

 marshes, insects must deal with the 

 osmotic and ionic problems of variable 

 salinity. In addition to having external 

 contact with salty soil and water, 

 herbivorous insects take in large amounts 

 of salt in their halophyte foods. 

 Waterproof integuments can protect their 

 bodies from the external sources (except 

 perhaps for brief periods after molting) . 

 Efficient osmoregulatory systems are 

 necessary for processing the saline plant 

 materials, however, and these are 

 energetically costly. Foster and Treherne 

 (1976) indicated that some salt marsh 

 insects are selective in their herbivory 

 and take algae of lower salt content, 

 while others regulate the movement of 

 foods through their alimentary canal to 

 reduce the salt load in the midgut. Some 

 even capitalize on the rinsing effect of 

 rainfall by feeding on plants which have 

 been washed and by reducing intake between 

 rains. In southern California, however, 

 such a strategy would be impractical, 

 unless life cycles were timed to coincide 

 with the rainy season. 



Only one southern California coastal 

 wetland has been comprehensively surveyed 

 for insects (Nagano et al. 1981). The 110 

 ha (270 ac) Ballona Wetland, already 

 disturbed by urban encroachment and 

 reduced tidal circulation, was estimated 

 to support 1,200 species of insects, based 

 on the identification of about 500 species 



The majority of coastal insect papers 

 comment only on selected species and 

 contain little ecological information. 

 Because so few of the insects are well 

 known, and because habitat continues to be 

 developed, Nagano (1981, in press) and 

 Moore and Legner (1972, 1974) express 

 great concern that many insects will 

 become extinct before they are discovered. 

 At least one, the Antioch shield-back 

 cricket ( Neduba extincta ; Orthoptera: 

 Tettigoniidae) already has: the only 

 specimen known was found preserved in a 

 museum after most of its habitat had been 

 destroyed. 



Several insects known to be linked to 

 coastal habitats are described below. The 

 following examples of marsh-dependent 

 species were provided by Nagano. 



The salt marsh water boatman 

 ( Trichocorixia reticulata . Figure 40) is 

 one of a few species in the family 

 Corixidae (Hemiptera) which can survive 

 the saline habitat. It eats algae and 

 protozoa from pools and comes to the water 

 surface to renew the oxygen content of its 

 air bubble or plastron. Cox (1959) found 

 adult T, reticulata in coastal ponds 

 ranging from slightly brackish to 160 ppt 

 salinity in southern California. 

 Occurrences in freshwater were rare, and 

 the species probably breeds only in saline 

 water. Reproduction occurred year-round 

 during Cox's study, but laboratory 



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