PARASITES OF SPIDERS AND THEIR EGGS. 



59 



Micaria (unknown). 



Pi'osthesiraa fiircata. 

 Drassitl (unknown). 

 Diassus lapiilicolens. 

 Aiirieai lirunnea. 



Pezoniachus obscurus. 



Hemiteles inicarivora. 



Hemiteles prosthesimre. 



Hemiteles tlrassi. 



Polyspliineta tuberosa.* 



Ilcuiitek'S teneiTinius.* 

 " " Hemiteles aianearum.* 



" " Heiuiteles formosus.* 



" " Pezomacbus fesciatus.* 



" " Pezomacbus corruptor.* 



" " Pezomacbus proxiuius. 



" " Pezomacbus zonatus.* 



Drassid (unknown). Eupelmus drassi. 



Laterigeade, Saltigrade, Citigrade. 



Laterigrade cocoon. Pezomacbus gracile. 



loius (unknown). Polyspbincta n. sp. 



Saitis i)ule.x. Acoloides saitides. 

 Pbidippus morsitans. " ' " 



Pardosa luteola. Polyspbincta 



Egg parasite. 



Body ]«irasite. 



Egg ])arasite. 



it u 



Body parasite. 

 Egg parasite. 



Egg parasite. 

 Body parasite. 

 Egg parasite. 



Body parasite. 



Generali 

 zations. 



IX. 



It is difficult to make any correct generalizations from tlie data in hand 

 on this mo.st interesting cliapter in the biology of .spiders, since the species 

 or even genus of the host is in so many cases unknown, even 

 when the parasite has been determined. But a few hints appear 

 from the study of the above lists and preceding facts which 

 may serve to at least open the way for others who in the future may 

 have more perfect information. 



First, it is evident that tJie exclusive occupation of a specific host by a 

 specific ijaest is not the fixed rule. For example, the eggs of Argiope co- 

 phinaria are parasitized by one species of Pezomacbus, two of Pimpla, and 

 two (though perhaj^s as hyperparasites) of Chrysocluiris. Again, Epeira 

 diadeniata of Europe serves as body host for three si)ecies of Polyspbincta, 

 and its eggs as host of one eacli of Hemiteles and Pimpla. Once more, 

 Agroeca brunnea of Europe has one species of Hemiteles for a body para- 

 site (?), and for egg parasites two species of Hemiteles and three of 

 Pezomacbus. Thus it would appear that the occupation of any sjjecitied 

 host is not limited to any specific guest, but lias a wide possible range, 

 both as to species and genera. 



Second, the preference of any specific guest is not cdways confined to one 

 specific host. Thus, Polj'spbincta carbonator, a European body parasite, is 

 reported as guest upon three species of Epeira ; and Polyspbincta boops 

 ufiou liotli Theridion and Epeira. 



Third, the (jucsts are not absolutely separated by their habits info distinct 

 ejroups of body parasites, on the one hand, and nest parasites on the other. 

 Thus, Polyspbincta carbonator is a body jiarasite upon three Epeiroid 

 species, but is reported as a guest upon unknown spider eggs ; P. rulipes 



