173 



some plants being noticeably more injured than others. An estimate of 

 the total damage done to the patch is about 20 per cent. Badly dam- 

 aged sprays selected at random showed an average of five or six injured 

 buds to each flower cluster. On one large spray over two-thirds had 

 been killed. 



From the examiuation of material collected at this date it was ascer- 

 tained that the work of the Strawberry Weevil on Blackberry does not 

 differ materially either in appearance or in ultimate injury from tliat on 

 the Strawberry. Some difilerences, however, were noted. It will be re- 

 membered that nearly all injured strawberry buds taken from the fields 

 May 17 contained larvre or eggs. The punctures were in nearly every 

 instance plainly seen both on the buds and on the stem beneath. The 

 latter were in many cases nearly cut tin ough. On the blackberry only 

 a small proportion of the blighted buds showed the punctures j)lainly,^ 

 and some, although cut at the stem, did not reveal any punctures what- 

 ever on the calyx, or on the corolla when the bud was opened. In other 

 cases where no punctures were visible on the outer surface of the calyx 

 an examination of the corolla within showed punctures in several i^laces. 

 Sometimes the wounded spot in the calyx had healed up or grown over 

 so as to be nearly invisible, and in other cases the punctures had been 

 made between the sepals or leaves of the calyx. Only eggs and freshly 

 hatched larvte were found at this date and a considerable percentage 

 (20 per cent) of the injured buds were entirely empty. 



Certain Varieties more affected than Others. — It has always been 

 noticed when opportunity has offered for comparison that the varieties 

 of strawberry, termed variously perfect-bearing, staminate, bisexual or 

 hermaphrodite are more severely injured than the pistillates or imper- 

 fect bearers, but no cause for this difference has been assigned. It has 

 also been observed that '' Sharpless " plants were much more badly 

 damaged than other staminate varieties. Observations made this sea- 

 son will, I think, explain the reasons. These observations indicate 

 that the injury to strawberry by this insect is in direct proportion (1) 

 to the quantity of pollen produced, and (2) to the amount of exposure 

 of the growing bads and the flowers to the sun. 



That pollen constitutes by far the larger proportion of the food of 

 the adults is, I believe, beyond question. It not only furnishes a large 

 portion of the food of the growing larva but is without doubt essen- 

 tial to its development. Those varieties whose flowers produce the 

 greatest quantity of pollen naturally serve to attract the most beetles, 

 hence the more pollen produced the greater the injury. This explains 

 why the " Sharpless" and other staminates are more severely attacked 

 than pistillates like the " Crescents," but I am indebted to Mr. W. A. 

 Taylor for an explanation of why " Sharpless " berries should be more 

 affected than other staminate varieties. 



On the farm of Mr. Walker two varieties, '' Sharpless" and "Charles 

 DoAvning," were growing, affording an excellent opi)ortunity for com- 

 parison. These varieties produce a similar amount of pollen, but in the 



