48 
days preceding, the next meeting of the American Association for the 
Advancement of Science. 
Mr. Riley 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 afew instances will show. 
In 1882, while 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 acaterpillar and brought her ovipositor into position. I captured 
her, and in my notes wrote ‘“‘ Found ovipositing upon the larva of Leu. 
cania unipuncta.” 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 perfect 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 
~ Jeaf. 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. | 
