GRAPEVINE ROOT WORM 23 



such a manner that the whole may be easily detached from the 

 vine, as is often the case when a strong wind is blowing. 



The duration of the egg stage was determined by repeated 

 observations both last year and this as from 9 to 12 days, about 

 one day being required for an entire mass of eggs to develop after 

 hatching commenced. We were also able to verify Professor 

 Webster's observation on the appearance of a narrow semitrans- 

 parent band or line near each end of the egg four days after 

 oviposition. Small numbers of empty egg shells, indicating that 

 hatching had begun, were found in Mr G. L. Hough's vineyard 

 July 24, 1902; and it is very probable that in Mr Clyde Dean's 

 vineyard at Portland, where conditions are about a week earlier, 

 young grubs had appeared some time before. 



Habits of the grubs or larvae. The) young larvae, after they 

 hatch from the eggs, drop to the ground, as observed by Professor 

 Webster and corroborated in our own experience. There seems 

 to be very little or no attempt on the part of these tiny creatures 

 to crawl down the stalk. A recently hatched grub is such a small 

 creature that it rapidly makes its way into any crevice or crack, 

 and when it drops on loose earth soon disappears from sight. 

 Earlier writers have recommended the covering of the roots of 

 grapevines as deeply as practicable at the time the young hatch, 

 so as to present more obstacles to the grubs when making their 

 way to the roots. This suggested to the writer some experi- 

 ments to determine the burrowing and traveling powers of these 

 little creatures. One small grub was placed on a piece of paper 

 at 9.27 in the moruing and its wanderings carefully traced with 

 a pencil till 4.43 in the afternoon. The little creature traveled 

 almost continuously during that entire period and showed a de- 

 cided tendency to turn to the left. It covered the relatively enor- 

 mous distance of over 47 feet in seven hours, or an average of 

 about 2 yards an hour. The grub was placed in a dry vial, and 

 under such unfavorable conditions lived about three days. This 

 would seem to indicate that the little creatures can make their 

 way over many obstacles if not confronted by very unfavorable 

 conditions. 



Some tests were also planned to ascertain the burrowing 

 powers of these little grubs. A glass tube 17 inches long and 

 £ inch in diameter was bent so that 4 inches were vertical. 

 It was then filled with loosely packed earth, and on July 29, 40 



