9 



bark of last year's wood, and may occur quite generally over the canes, 

 some quite near to the upper wire of the trellis. As stated by Professor 

 Webster «,' 700 eggs were found on a single vine, and 225 eggs from a 

 section of a cane but 16 inches long. The eggs are nearly cylindrical in 

 shape, tapering at each end ; whitish when first laid, but soon becoming 

 yellowish in color. The eggs are about one-twenty-fifth of an inch in 

 length, and more or less concentrically arranged in patches. From 9 to 

 12 days are required for the eggs to hatch. See figure 1, at 6 and c, 

 showing eggs on graj)e cane and more enlarged. 



Larva. — On hatching, the larvae drop to the ground. At this time 

 they are about one-seventeenth of an inch in length, and from their 

 small size are readily able to find their way through the soil. Although 

 the powers of locomotion and endurance of the young larvae are con- 

 siderable, to enable them to overcome difficulties in reaching their food, 

 many doubtless fail to do so and perish. When established on the roots, 

 however, the grubs feed freely and grow rapidly. By fall the majority 

 of them will be full-grown or nearly so. Upon the approach of cold 

 weather they descend into the earth several inches, a few as much as a 

 foot below the surface, and here construct oval earthen cells in which 

 they pass the winter. With the approach of warm weather the larvae 

 ascend to a point near the surface, the immature ones completing their 

 growth, and the pupal stage is entered mostly from about 2 to 3 inches 

 below the surface of the soil and witliin a radius of 1 ^ to 2 feet from the 

 base of the vine. The full-grown larva is about five-eighths of an inch 

 long, the body whitish, resting in a curved position. The head is yel- 

 lowish brown in color, with a transverse diameter somewhat less than 

 that of the body. The spiracles or breathing pores along each side are 

 well marked, varying from light to yellomsh brown in color. As shown 

 in figure 1, at (Z, the insect in this stage resembles in miniature one of 

 the common white grubs, from which it may be distinguished by the 

 dark food material in the abdomen of the latter. 



Pupa. — The full-grown larva prepares an earthen cell, within which 

 it shortly changes to the pupa or 'Hurtle" stage. In this condition 

 the insect is soft and helpless, and the earthen cells are readily broken 

 open and the pupae crushed or otherwise killed by stirring the soil. As 

 stated, the majority of the larvae pupate about 2 or 3 inches below the 

 surface of the ground, and this makes possible their destruction in 

 large numbers by timely cultivations, as will be explained under 

 the discussion of remedies. Pupation is perhaps at its height just 

 before the blossoms of the grape begin to open, but the vineyardist 

 may determine the period with exactness by examining the earth 

 around the base of infested vines to ascertain the proportion of pupae 

 and larvae present. Throughout the Chautauqua, Erie, and Ohio 

 grape belts, during normal seasons, the insects will be in the pupal 

 stage in maximum numbers during the first two or three weeks of 

 June, varying somewhat, however, according to season and the char- 

 acter of the soil, being earlier on sandy and later on clay soils. The 

 pupa is shown in fi^ire 1 at e. It is from one-fourth to one-third of an 

 men long, whitish in color, but with a pinkish coloration about the 

 head, thorax, and caudal portion. On the head, body, and append- 

 ages are spines, as shown m the figure. The pupal stage lasts about 

 two weeks. 



oBul. 62, Ohio Agrl. Exp. Station, p. 82 (1895). 

 27724— No. 284—07 2 



