THE VAGABOND CRAMBUS : ITS LARVA. 143 



result, it is believed, of its uot having been given the needed condi- 

 tions for its hibernation. The period at which the hatching occurred, 

 and the conduct of the larvse during the time that they wore observed, 

 leaves scarcely doubt that their habit, in nature, is to feed but sparingly 

 during the autumn, and to pass through one or two meltings, after which 

 they retire to suitable quarters for their hibernation, remaining in a 

 lethargic state until the starting of the new grass in the spring fur- 

 nishes them with food.* 



Present Condition of the Devastated Pastures. 



Through the kindness of Mr. Adams, I am enabled to give the 

 present appearance of the injured pastures in the vicinity of Water- 

 town, N. Y. Under date of December 38th, he has written me : "The 

 effects of the late raid still show in the absence of any blades of grass 

 of length. Every thing is cropped short, except in small bunches here 

 and there where manure was dropped. The grass has shown greenness 

 this fall to a much less extent than would otherwise have been the case. 

 There are evidently many dead roots as well as some live ones. Another 

 raid in these pastures would probably prove fatal to the present sod." 



It will be remembered that the depredations in Jefferson county 

 were not nearly so serious as in St. Lawrence county. 



*Professor Riley has recently published in the Annual Report of the Department of 

 Agriculture for the year 1881, observations made upon the young larvae occurring in large 

 numbers, in the District of Columbia. They are given here, as supplying an important part 

 in the life-history of the species which I have endeavored to present: — 



" The larvpc, if not too numerous, are difficult to find, on account of their nocturnal 

 habits, but more particularly from their secluded mode of life. From the time of hatching 

 to the assumption of the pupa state they remain nearly in the same spot. The newly- 

 hatched larva spins a delicate white web, near or among the roots of the grass, and com- 

 mences at once to feed upon the softer parts of some leaf near at hand, or to bore through 

 the surrounding sheaths into the stem itself, near its base. Whenever they have settled 

 they protect themselves by a delicate web, which they gradually cover with their greenish 

 frass, forming a tube, in which they are entirely hidden from view. They are very slug- 

 gish, and, if the tube be disturbed, curl up into a helix-like roll. As they Increase in size, 

 the tube is extended either upward, when upon the ground, or downward, if somewhat 

 above the surface, and the opening is often lined with bits of green grass." 



Some interesting observations upon the tube of the mature larva are also given in con- 

 nection with the above : — 



" When the larva is full-grown its tube measures often, nearly 50 mm. (two inches) in 

 length. A half-inch at the lower end is thicker than the rest, is rounded and closed, serving 

 both as a retreat for the larva and as a receptacle for excrement. The upper or open end 

 is usually very delicate, and is generally so constructed that if the larva is disturbed it 

 closes entirely. When full-grown and ready to transform, the larva leaves its tube and 

 commences to spin among the roots, and near or just beneath the surface of the ground, 

 an elongate club-shaped cocoon, similar in appearance to the lower end of the larval tube. 

 It is composed of smooth and delicate white silk, gummed over with earth. Both ends are 

 rounded, the thicker end being about 6 mm. in diameter, and the narrow end about 4 mm." 



