GRAPEVINE ROOT WORM 19 



more vigorous, thrifty vineyards. It may be that a slight over- 

 crowding, as in the case of some other insects, impels the beetles 

 to flight. This means that poor vines are relatively safe, while 

 the better ones are liable to injury and are consequently the 

 places where it is most important to control the insect. These 

 inflying beetles will lay eggs if conditions are favorable, and the 

 earlier they appear the more eggs will be deposited. 



Eggs. The eggs of this insect are deposited almost entirely 

 under the loose bark of last year's wood, many being found 

 as high as the top wire. Professor Webster states that over 

 700 have been taken from a single vine, and from a section 16 

 inches in length and an inch in diameter he took 225 eggs. 

 Once he found a few eggs pushed down between the earth* and 

 the base of the vine, but we have failed to find eggs in any such 

 position. Beetles in confinement deposited eggs in crevices and 

 cavities of the wood and even on leaves. Eggs were found in the 

 field in 1902 as early as July 9, and oviposition was still in prog- 

 ress Aug. 15, and, though beetles were less abundant than three 

 weeks before, it was still easy to find individuals which con- 

 tained fully developed eggs. The first deposited in 1903 were 

 found about July 3, and in our indoor breeding cages oviposition 

 continued till into September. Experiments were planned, both 

 this year and last, to determine the duration of the period of 

 oviposition, the time when the eggs were laid and the total num- 

 ber deposited by females. A number of pairs of beetles were 

 isolated and provided daily with fresh food. The work in 1902 

 demonstrated that a number of beetles might continue to deposit 

 eggs for a period of over 40 days, and certain individuals from 

 seven to 13 days. These records gave totals of 187, 141 and 106 

 eggs for individuals. This was interesting, but it was felt that 

 the limit had not been reached, and consequently the studies were 

 conducted on a more extended scale this year, and the results 

 more than justified the labor, as will be seen by the appended 

 table. 



