October, '16] SMITH; DEFINING HOST RELATIONSHIPS 485 



to this work of parasite upon parasite and while it is perhaps un- 

 scientific to allow one's opinions to outstrip the facts, especially when 

 so few life-histories of parasites are known, I doubt if true quaternary 

 parasitism as defined above really exists among entomophagous in- 

 sects. Accidental quaternary parasitism does of course occur in the 

 case of omnivorous or general feeders such as Dibrachys or Melittobia 

 and so far as this type of insects is concerned there is practically no 

 limit to the numerical relations which may develop. Dibrachys will, 

 for example, breed upon Asecodes and in its turn Asecodes will breed 

 upon this generation of Dibrachys, and while this sort of thing can 

 hardly go on ad infinitum as Burns would have us believe, it would 

 certainlj^ continue as long as the food supply lasts. 



SUPERPARASITISM AND MULTIPLE PARASITISM 



Superparasitism has been defined by Fiske (loc. cit.) as that form of 

 symbiosis resulting "when any individual host is attacked by two or 

 more species of primary parasites or by one species more than once." 

 We have under superparasitism as defined by Fiske two quite distinct 

 phenomena. These were later designated by Pierce (loc. cit.) as can- 

 nibal superparasitism and mixed superparasitism. In a previous 

 article Mr. Pierce gave to the latter phase of parasitism the term ac- 

 cidental secondary parasitism. This phase or rather these phases of 

 parasitism have been so ably treated by the two entomologists men- 

 tioned, that there remains little to be said in this connection and those 

 interested are referred to the two articles for further information. 

 However, since the avowed purpose of this paper is to standardize the 

 terminology of the host relations of entomophagous insects the subject 

 cannot logically be left with two terms for the one phenomenon in one 

 case and one term for two phenomena in the other. 



The writer would suggest that the term superparasitism be re- 

 stricted to those cases where there is a superabundance of parasites 

 of a single species (cannibal superparasitism of Pierce). It frequently 

 happens, especially when the total percentage of parasitism runs 

 abnormally high, that the mother parasite deposits many more eggs 

 than can possibly reach maturity on a single individual host, or in 

 other cases, after one female parasite has laid her quota of eggs another 

 female of the same species, lacking the ability to distinguish between 

 parasitized and unparasitized hosts, deposits a further supply in the 

 same individual. This phenomenon alone I would term superpara- 

 sitism, leaving the other phase included in Fiske 's superparasitism to be 

 termed multiple parasitism (Pierce's accidental secondary parasitism 

 and mixed superparasitism). 



By way of definition I would suggest the following: Superparasitism 



