On the Parasitism 0/ E-hipiphorus paradoxus. 393 



XLVI. — Observations on the Parasitism o/" Rliipiphorus para- 

 doxus. Bj Frederick Smith, Assistant in the Zoological 

 Department of the British Museum. 



Every entomologist will read Mr. Murray's paper on Phipi- 

 jphorus with great interest 5 I have certainly done so, because 

 I had been obligingly informed by the author of the aim he 

 had in view, that of proving the larva of Rhipiphorus to be, 

 as the American entomologists have ha^Dpily termed it, "a 

 guest-insect " whose larva feeds upon the food supplied by 

 the wasp, and not a parasite that preys upon its larva. 



I had certainly considered that the habit of the larva of 

 Rhipiphorus had been clearly established by Mr. Stone five 

 years ago ; I therefore looked forward to the publication of 

 ]\Ir. Murray's paper with great interest. 



When I refer back to the correspondence which I possess 

 from Mr. Stone, and refresh my memory by so doing, I at 

 once confess myself satisfied as to the habit of Rhijjiphorus, 

 and still beheve its larva to be a carnivorous parasite. 



I had the pleasure to hold a most interesting correspon- 

 dence with Mr. Stone relative to the habits of the wasp and its 

 parasites, during a period of about six years, and so am satis- 

 fied as to his accuracy of observation, his most scrupulous 

 adherence to facts, and facts alone ; for he never indulged in 

 theory ; he was a plain straightforward observer, indefatigable 

 in the search after truth, and unremitting in his attention to 

 the most minute details in all his investigations. 



It appears to me only necessary to read a single paragraph 

 in a communication which I had the pleasure of laying before 

 the Entomological Society, on Mr. Stone's behalf, to convince 

 any person of the habit of Rhipiphorus ; it is as follows : — 



" On the 19th of August I was more fortunate ; for on 

 taking out a nest of Vespa vulgaris^ and proceeding to open 

 the closed-up cells, I found a larva of the parasite firmly at- 

 tached to the full-grown larva of the wasp, the mouth of the 

 former buried in the body of the latter just below the head, 

 its neck bent over that of its victim, whose body appeared to be 

 tightly compressed by that of its destroyer, showing the latter 

 to be possessed of a considerable amount of muscular power. 

 Itwas of minute size when discovered, andappeared to have only 

 very recently fastened upon its victim ; but so voracious was 

 its appetite, and so rapid its growth, that in the course of the 

 following forty-eight hours it attained its full size, having 

 consumed every particle of its prey, with the exception of the 

 skin and mandibles, which, from observations I have since 

 been enabled to make, these creatures retain in their grasp 



