48 



(lays preceding, the next meetiug of the Anierican Association for the 

 Advancement of Science. 



Mr. Eiley read a paper entitled '■'■ Dermestes vulpinus and Tobacco," 

 which is held for publication elsewhere. 



Mr. Southwick stated that he had found Dermestes under the bark of 

 a mahogany log in New York, and that it had entered this crevice for 

 pupation after having originally fed upon some animal matter. 



Mr. Howard read the following note : 



A NOTE ON PARASITES. 



By L. O. Howard, Washington, D. C. 



The object of this brief note is to impress upon the members of this 

 association the fact that one can not be too careful in statements for 

 publication concerning the relation between a given parasite and its 

 host. 



The possibilities of error are very great, as a few instances will show. 



In 1882, whde studying the Army Worm at Huntsville, Ala., I no- 

 ticed an Ichneumonid walking about a fence-rail over which the worms 

 were swarming in countless numbers. The parasite was apparently 

 excited, walked and flew from one part to another, occasionally alighted 

 upon a caterpillar and brought her ovipositor into position. I captured 

 her, and in my notes wrote " Found ovipositing upon the larva of Leu- 

 cania unipiincta. " Now it transpires that this Ichneumonid was Bassus 

 scutellatus, and, as the concensus of rearing experiments shows, the 

 species of this genus are parasites of Diptera, and my inference was in 

 all probability entirely mistaken. If the original observation had been 

 published it would have been absolutely necessary for jierfect safety to 

 have detailed the circumstances in order that future students should 

 not be misled. 



Recently a well-known entomologist sent to Professor Riley specimens 

 of the common Pteromalus puparum with the record "Reared from the 

 cells of a mud-wasp." From what we know of the habits of this para- 

 site we may take it for granted that had the entomologist in question 

 examined the cells of his mud-wasp he would have found specimens of 

 some lepidopterous larva or pupa stored up as food for the young of 

 the wasp and that from these stored-up insects the parasite had 

 emerged. 



Within the last few weeks specimens of a Chalcidid were received 

 from a most careful observer and excellent collector, with the statement 

 that they were reared from the eggs of a saw-fly deposited in a willow 

 leaf. While I am not in the habit of discrediting any statement which 

 this gentleman makes, and while I have learned by experience that his 

 accuracy is something astonishing in this world of error, the fact re- 

 mains that this parasite is plainly from the known habits of its near rel- 

 atives an enemy of some lepidopterous or dipterous leaf miner, and that 



