480 JOURNAL OF ECOXOMIC ENTOMOLOGY [Vol. 9 



are some species of insects, like Aphelinus mytilaspidis, for example, 

 which are both predaceous and parasitic, feeding either upon the adult 

 insect, or the progeny beneath the parent insect. The distinction 

 between parasitism and predatism is of no great importance, but it is 

 well to bear in mind that many of the so-called parasites are parasites 

 only because they belong to a parasitic group, and not by reason of 

 their method of feeding. 



The interrelations of the parasites themselves are quite complex 

 and, it seems to the writer, not as yet well defined. A knowledge of 

 these interrelations is of not a little importance when the subject of the 

 control of noxious insects by their insect enemies is under consideration. 

 There have been used in the past a number of phrases and terms to 

 designate the different kinds or types of host-relations and of interre- 

 lations of the parasites themselves, many of them used in one sense 

 by one author and in an entirely different sense bj^ another. Ob- 

 viously this is not conducive to a clear understanding of the subject 

 and should if possible be avoided. Some of these terms and phrases 

 are hyperparasitism, secondary parasitism, tertiary parasitism, su- 

 perparasitism, accidental secondary parasitism, cannibal superparasi- 

 tism, mixed superparasitism, true secondary parasitism, multiple 

 parasitism, etc. 



Hyperparasitism 



The term hyperparasitism is generally used to denote any stage of 

 parasitism other than primary. That is, either a secondarj^ parasite 

 or a tertiary parasite is a hyperparasite. This is a useful term in the 

 entomological vocabulary and is generally confined to the above mean- 

 ing, although some use it synonymously with "secondary." Misuse 

 of the term occasionally occurs when, for example, parasites of lady- 

 birds are called hyperparasites. There is certainly no valid excuse for 

 calling a parasite of ladybirds a hyperparasite, since it is not a parasite 

 of a parasite, but is simply a primary parasite of Coccinellidse. The 

 fact that ladybirds are usually beneficial should have no bearing in the 

 case, and such use of the term is only confusing. Neither should 

 primary parasites of any other predaceous insects such as Leucopis, 

 Chrysopa, Syrphus, etc., be called hyperparasites, although we find 

 such use of the term occasionally in entomological literature. 



Indirect Parasitism 



Indirect parasitism, which is a type of hyperparasitism, is most 

 closely related to secondarj^ parasitism, and has not heretofore been 

 defined. This type of host-relationship can best be illustrated by ex- 

 amples. One of the most noteworthy instances of this type is the Chal- 



