14 



On the 7th June, after several hours of careful search in cornfields 

 near Lexington, McLean county, where I selected by preference the 

 least thrifty fields, I found no living larvae, and but a single mass 

 of webbed dirt at the base of a stalk precisely similar to those formed 

 by the Aveb worm, the hill containing it having been evidently dam- 

 aged some time before. 



A number of the larvse were brought to the office and placed in 

 earth in a breeding cage on the 28th May. On the 14th June 

 those in the breeding cage were transferred to fresh corn. 

 Many of them were dead, but nine active specimens remained. On 

 the 33th the com was renewed and another search was made. No 

 larvse were found and but two living pupae. A single imperfect moth 

 was released from the earth in which it had completed its trans- 

 formations, but it was not able to expand its wings and could not 

 be determined. One of the other pupae was unfortunately crushed 

 by accident, and the other was badly infested by mites which clung 

 closely to its crust about the head with inserted beaks. These were 

 carefully picked away, and this sole remaining pupa was returned 

 to thoroughly calcined earth to complete its transformations. On the 

 22d July it emerged as a small gray moth, evidently belonging to 

 the family Pyralidae. 



From Prof. C. H. Fernald, to whom I referred the specimen, I 

 learned that it was a species of Crambus new to him and probably 

 undescribed. On the 3d July Mr. Mills, of Dwight, wrote me that 

 the larvae had almost entirely disappeared from the corn fields, and 

 that the season had been so favorable to the crop that no percepti- 

 ble damage had finally resulted, with the exception of the loss of a 

 few hills here and there. 



DESCKIPTION. 



Larva. — The presence of this larva in the earth may be suspected 

 when an irregular mass of webbed dirt is found among the roots of 

 the cornj an inch or less beneath the surface. If this mass be 

 picked open, the larvae will usually be found safely ensconced within. 



The individual web worm is characterized by its pale reddish 

 brown color, nearly black head, dusky yellow neck or cervical 

 shield, and by the extraordinarily large "piliferous tubercles," each 

 bearing an unusually long black hair. These "tubercles" are not 

 elevated, but consist of smooth shining areas, of a firmer consis- 

 tency and a darker tint than the adjacent surface. 



The head is dark chocolate brown, slightly and irregularly rugose, 

 and bears scattered long hairs of a yellowish color. Upon the front 

 is an S-shaped white mark which does not coincide with the sutures 

 of this region, the branches of the S lying some distance outside 

 the corresponding sutures, and the common stem being relatively 

 short. The cervical shield is yellowish, with a white median line, a 

 whitish anterior edge, and an oval black spot on the sides near the 

 middle of the lateral margin. Surface with a few scattered long 

 dark hairs. Below the lateral edges of the cervical shield, are two 

 large piliferous tubercles with the anterior spiracle situated in an 

 emargination at the upper posterior angle. The second and third 



