02 GRAPE CULTURE AND 



given for the failure, more than the suggestion that the con- 

 ditions may not be favorable in a glass vessel for the produc- 

 tion of the form whose natural home is upon the leaves or 

 stock. There is, also, a possibility that these eggs may not 

 hatch even when under favorable conditions in this district; 

 for the winged insect has been repeatedly seen upon the stock 

 and leaves in a perfectly quiet condition, but no eggs have 

 ever been found with them. In fact, no eggs of any kind have 

 ever been found upon the upper part of the vine. When the 

 insects are confined in a vessel the eggs are soon laid. 



Winter Egg. The solitary egg, commonly called the win- 

 ter egg has also not been found, although it has been the ob- 

 ject of diligent search at all times. It is to this form that 

 much attention is being directed in European countries, as 

 its extinction offers a possible means of checking the ravages 

 of this pest. It is also supposed that a close relation exists 

 between this egg and the gall-type. If such a relation does 

 exist we should have found this form later in the summer up- 

 on the vines whicri bore the gall last year. A careful search 

 did not reveal it last winter. 



Probable Underground Development in place of the Winged 

 Form. The larvae from the winter egg, of course, we have 

 not met as a product from the natural course of development 

 through the winged form, but their appearance must have 

 escaped our notice through the other parallel line of develop- 

 ment which is accomplished entirely underground, and which 

 is described as differing only in its possible greater prolificacy 

 from the ordinary root louse. 



This line of production may have been that from which 

 come the insects noted in a previous report (1882). Their 

 peculiar appearance at the time led to doubts as to what stage 

 of development they really represented. It was even conjec- 

 tured that they were the sexual individuals. 



