REPORT OF THE STATE ENTOMOLOGIST I904 375 



It will be observed on referring to the two columns under date 

 of July 6, that the beetles were decidedly more abundant in the 

 southern than in the northern end of the plat, as previously stated. 

 The separate figures given in each space refer to the number of 

 beetles, egg clusters or grubs taken on or under individual vines, 

 and when more than one is given, it means that several in the 

 same row were examined. The experimental area was carefully 

 watched from time to time, and at more or less regular intervals 

 a Hough beetle catcher was used to collect the beetles from single 

 vines in order to ascertain the number present in various portions^ 

 of the treated and untreated areas. It is interesting in this con- 

 nection to compare the average number of beetles on vines about 

 the middle of the sprayed and unsprayed areas; in other words, 

 on rows 3 to 7 in the sprayed area and rows 14 to 18 in the unsprayed 

 section. In the former there were, July 6, 45.66 per vine; July 

 II, 12.8; July 14, 21.2 and July 20, 13.8. These figures should 

 be compared with the following from the unsprayed area. July 

 6 there was an average of 41.66 per vine; on the nth 57.5; on the 

 14th 49 and on the 20th 12.25. It will be seen that the numbers- 

 were approximately equal on the first and last named dates, and 

 the considerable discrepancies observed on the nth and 14th are 

 probably to be explained in a large part by the effect of the poison 

 applied June 30 and July 6. Still the above data hardly allows 

 us to accurately estimate the total number of beetles destroyed. 

 July 6 there were signs of considerable eating on both sprayed 

 and unsprayed rows, it being specially evident on the latter. We 

 consider this somewhat unreliable evidence as to the amount of 

 protection afforded, since the beetles on sprayed vines feed to a 

 considerable extent on sheltered leaves and in places hidden from 

 observation, evidently in an attempt to find foliage free from 

 poison. An examination July 8, nine days after the first spraying 

 and two after the second, resulted in finding the remains of 9 dead 

 beetles under about 15 vines in the southern section of the vine- 

 yard. There were a great many living, apparently healthy insects 

 on the vines, and there appeared to be no marked inclination to 

 forsake the sprayed area. The jarring of a typical vine in row 6, 

 resulted in the capture of 35 beetles, and another in row 13 in taking 

 61 beetles. July 11 the remains of 7 or 8 dead beetles were found 

 after an extended search under about 15 vines, and on the i6th 

 it required two hours to find two dead insects under a number of 

 vines, indicating plainly that comparatively small numbers were; 

 killed by the poison. An examination July 21 resulted in taking' 



