GRAPEVINE BOOT WOEM 37 



than 26^ of the catch on the 7th. About 154,900 beetles were 

 tfiken from this area of approximately 5 acres, 3 of which were 

 much less infested than the 2 next the experimental cages. This 

 means that an average of 59 beetles was secured from each vine 

 in spite of the fact that a considerable proportion of the area had 

 been previously cultivated for the special purpose of destroying 

 the pupae. These figures give some idea of the immense number 

 of insects which must have been in the vineyard when work was 

 begun last spring. 



As further evidence of the value of collecting for this insect, 

 it may be interesting to state that last spring, sample diggings 

 under different vines in the experimental area, gave from 8 to 

 50 or more grubs or as calculated from 60 to 400 or more to a vine, 

 in one case it was estimated that there were fully 1000 under a 

 single vine. Sample diggings in October resulted in obtaining 

 no grubs from three vines, one only from each of three^ and two 

 only from two others, indicating that there were very few which 

 had more than 12 or 15 grubs, and that, in all probability, the 

 number to each vine would hardly exceed eight or nine. In other 

 words, cultivating and collecting in one season reduced the num- 

 ber of grubs about 98^. These figures are sufficiently striking, 

 so that no further comment is necessary on the efficiency of 

 collecting and destroying the beetles ; in fact, this vineyard after 

 one season's work may be considered more free from the pest 

 than almost any other in that section, and it will compare very 

 favorably with those in places where Fidia has caused practically 

 no injury. 



Our experience with collectors has demonstrated the practica- 

 bility of catching the beetles, and we recommend this operation 

 for all badly infested sections, and that the collecting be begun 

 as soon as the beetles appear on the vines in any number, say, 

 when there are 12 or 15 on one. The operation should then be 

 repeated at intervals of five to seven days till the vines have 

 been gone over two, three and possibly four times, dependent 

 somewhat on the number of insects which are captured. It will 

 be found that it is much easier to catch the beetles on warm 

 days, when it should be done, than in cool weather. 



