biotope, for instance Lispe tentaculata (family Muscidae) , Dexiopsis 

 lacteipennis (family Muscidae, according to Hugo Andersson, Lund, pers. 

 comm. , not known in this county before), Scatophaga litorea (family 

 Scatophagidae) , and Ephydra macellaria alandica (family Ephydridae) 

 contribute only 10% of the total number of flies while Dolichopodidae 

 and Agromyzidae made up the major parts (49% and 26%, resp.). Some 

 of the flies are parasites on other insects, e.g., individuals of Phoridae 

 (Chinery, 1976) and Tachinidae (Lindroth, 1967). One individual of the 

 family Pipunculidae was found at Station G. Members of this group are 

 known as parasites of cicadas (Homoptera) (Lindroth, 1967) and were 

 found only at this station. 



Some of the parasitic hymenopteras are fly parasites, e.g., 

 Tricopria sp. and Trimorus sp . These were also found at Station G where 

 the greatest number of flies occurred. The only hymenoptera species 

 which truly belongs to the shore is Urolepis maritima which appeared at 

 Station G. Most of the Ichneumonidae would seem to have come from the 

 woods (Cederholm, pers. comm.). Perhaps these were also attracted by 

 the detergent. According to Backlund (1945) nearly every wrack bed 

 contains parasitic hymenopteras living on dipterous larvae. 



The high number of ants (Formicidae) at Stations B and D could be 

 explained by ant hills in the wood beyond the shores. 



A greater part of the spiders consisted of the species Oedothorax 

 retusus, (family Linyphiidae) , small web-spinning spiders which are 

 found especially in littoral vegetation and on the surface layer of 

 wrack (Backlund, 1945). The genus Erigone (family Linyphiidae) was also 

 found. One third of all the spiders was made up of Lycosidae, hunting 

 spiders which probably live to a greater extent on flies (Backlund, 

 1945). The genus Arctosa , Trochosa and Pardosa were also found. 



All of the ticks found belonged to the species Ixodes ricinus , 

 which live in decaying organic material and lay their eggs in the ground 

 vegetation (Ursing, 1971). At Station G there was more vegetation 

 around the wrack bed, which could have influenced the number of aphides 

 (Aphididae) which occurred here in larger numbers than at any other 

 station. One species ( Hyalopterus pruni) has for instance Phragmites as 

 i summer host (Lindroth, 1967). It is possible that the individuals 

 found belonged to this species, but no further examination was made. 



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