OF WASHINGTON. 177 



Prof. Riley stated that he doubted if they could be termed 

 myrmecophilous, since they did not get their prey with the 

 ants ; and also that their resemblance to the ants was hardly 

 mimetic because no or little advantage results, and mimicry is 

 always of a protective significance. 



Prof. Riley presented a note on the life history of the Dia- 

 brotica 12 punctata* which was called forth by a recent paper 

 in Psyche on the insect by Mr. H. Garman. He first referred 

 to an article on the food habits of the beetle, in Vol. I, p. 59 

 of Insect Life, in which by a typographical error the insect is 

 stated to have "bred" upon melons instead of "fed" upon 

 melons, the first statement being justly called in question by 

 Mr. Garman. 



He followed with a record of his notes on the corn-feeding 

 habit of the larva of this insect, which was first brought to his 

 attention in the spring of 1883. During this year and in 1884 

 and in 1886, he had succeeded in bringing together a full 

 record of the larval habits, an account of which was given. 

 Figures of the egg, larva, pupa, adult insect and nature of the 

 injury to young corn were exhibited, and descriptions of all 

 stages were given. 



Two dipterous parasites were referred to, one obtained from 

 the larva and the other coming from the adult. 



In the discussion Mr. Schwarz remarked that the history of 

 this insect presents a very interesting but not unusual experi 

 ence, viz., that a certain species may live year after year in the 

 neighborhood of cultivated plants without doing injury, and 

 then suddenly develop an extremely injurious habit. He 

 believed that the wild food-plants would be found to be 

 numerous. 



Prof. Riley held that the fact that it is now injurious does 

 not argue that the habit is of recent formation, although the 

 presumption is always strong that this is the case, especially 

 in view of the attention hitherto paid to corn insects. 



Mr. Kuehling said that ten years since he had known young 

 corn to be destroyed by probably the same insect near Mt. 

 Vernon, Va. 



Prof. Riley then presented the following communication : 



* Published in full in Insect Life, Vol. III. 



