66 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l 



Among the Insecta, the apparent importance of the Diptera and 

 Trichoptera is not well established. These groups rate high in number 

 of species serving as hosts, but as the flukes reported from them are 

 mostly larval forms of which the adults are not known and which 

 may later prove to represent no more known species than are already 

 known and recorded here from these hosts, or only a few more, these 

 groups cannot be rated at the present time as any more important than 

 the Odonata or Ephemerida as hosts for flukes. 



Nematoda 



No. of host 

 Inteimcdiate spp. 



host group involved 



Crustacea : 



Copepoda 8 



Amphipoda 2 



Isopoda 2 



Cladocera i 



Insecta : *> 



Diptera 67 



Coleoptera 39 



Orthoptera 5 



Siphonaptera 5 



Ephemerida 2 



Anopleura i 



Isoptera i 



Mallophaga i 



Odonata i 



Arachnida 6 



No. of parasite spp. 



with known hosts 



for adults 



7 

 2 

 2 

 I 



17 

 10 



5 

 4 

 

 I 

 I 

 I 

 I 

 6 



No. of parasite 



spp. reported as 



larvae without 



known hosts 



for adults 



Among the Crustacea, the Copepoda are the important group as 

 carriers of parasitic nematodes. Among the Insecta the Diptera are of 

 striking importance, no less than 6"^ of the Diptera being reported as 

 carriers for a total of 17 nematode species, this fact being the result 

 largely of the role of the mosquitoes as carriers of filarids. The 

 Coleoptera take first rank as carriers of spirurids. Of lesser impor- 

 tance are the Orthoptera and Siphonaptera, and the other groups of 

 insects show but few host species and these accused of carrying but 

 one nematode parasite. The Arachnida as a whole have been accused 

 of carrying 6 nematodes, and but 6 arachnids are incriminated. The 

 arachnids have not been reported as carriers of any parasitic worms 

 other than nematodes. 



