168 JOUKNAL OP ENTOMOLOGY AND ZOOLOGY 



THE BEETLE 



In the galls made by the fly lar\ce are often found the larvae of 

 the beetle, MordcUistiua iniicolor Lee, which are neither the gall 

 makers nor the parasites, but simply live in the galls without having 

 anything to do with the host. This beetle has been mentioned in 

 the Canadian Entomologist, by W. H. Harrington. J. B. Smith 

 described the adult in "A Synopsis of the Mordellidae of the Uniteci 

 States," Trans. Am. Ent. Soc, 1883, pp. 73-100, as also did 

 Blatchly in Coleoptera of Indiana, 1910, p. 1322. The rearing of 

 the species from the gall was mentioned by W. H. Ashmead in 

 Proceedings of the U. S. National Museum for 1888, p. 611. The 

 structure, habits and the life history have not been made known 

 hitherto. 



Observations were made on the different stages through the 

 whole year, especially on the activities of the adult during the last 

 part of the spring and the first part of the summer. The larva lies 

 in a narrow tunnel which is just wide enough for containing its body. 

 The tunnel is more or less winding, made in the common paren- 

 chyma, but never in the center of the gall. In most cases a single 

 larva lies therein, sometimes two are found in one tunnel, and also 

 more than one tunnel is found in the same gall, either communicating 

 with each other, or separated. In filling up a part of the tunnel 

 some dry, dust-like substance is deposited; this is the waste material 

 made by the larva (see fig. 3h of Plate 1). In a few cases the 

 larva was found in the central cavity. The larva lives in the gall 

 from the summer to following spring. The beetles were first seen 

 on June 8. Afterwards I reared a number of them from the galls 

 kept in the breeding jars. They were found in the fielci till the first 

 part of August. 



Mating. — Several beetles were put in an 8-ounce bottle, placed 

 on the window toward the sunshine. They were flying and jump- 

 ing actively. At first a male came to a beetle (sex unknown) , jump- 

 ing upon the front of the latter, trying to mate, with its genitalia 

 stretching out and bending downwards. The latter was unre- 

 sponsive. Afterwards, the vigorous male desisted, and wandered 



