66 Bulletin 64. 



7. The Blue Grass Worm. 



Cranibus teterrellus. 



PLATES I., VI., XII., Fig. 7. 



This species has not been found in Ithaca, although it occurs 

 in New York State. The moth may be recognized by its dark 

 yellow color, the silvery subterminal line bordered by dark rufous, 

 and by the black dots upon the outer margin at the tips of the 

 veins. In Missouri this species is reported to outnumber all the 

 other species of Crambus. The moths are most abundant about 

 the first of August. The eggs are salmon color. The larvae are 

 a dingy white, and are found in galleries of fine white web in the 

 grass. The web and the grass near by become sprinkled with the 

 castings. In the dry weather of August and September larvae 

 were found on withered portions of a lawn, and they were evi- 

 dently responsible to a considerable degree for the faded appear- 

 ance and scanty growth of the blue grass during the latter part 

 of the summer. 



Miss Murtfeldt says :* "The growth of the larvae was very 

 slow and seemingly out of all proportion to the amount of web 

 tubing constructed. A single larva, not more than one-third of 

 an inch long, seemed to require for its domicile a gallery of 2 to 

 2^ inches in length and with a diameter two or three times its 

 own. The upper part of this tube would be exceedingly diaph- 

 anous, but as it descended more and more of the frass was inter- 

 mingled until at the base it became quite compact. During the 

 day the larva rested quietly in this retreat, but at night it 

 emerged and fed upon the freshest of the contiguous blades. So 

 far as I could ascertain it seldom or never cut through the stalk 

 or bored up or down through the heart of the plant. 



The larvae seemed to attain maturitj^ from the middle to the 

 last of September, after which they rested quietly for some tiine 

 in their galleries, without inclosing themselves in more protective 

 cocoons." 



This apparent maturity was probably the cessation of active 

 feeding, preparatory to hibernating. As the adults do not fly till 



* Miss Murtfeldt, Bulletin No. 30, U. S. Department Agriculture, Entomo- 

 logical Division, p. 53. 



