68 NEW YORK STATE MUSEUM 



approach of cold weatlier descend deeper in the earth. Pro- 

 fessor Webster records finding the grubs a foot below the sur- 

 face in the spring, and our own observations indicate that they 

 descend nearly to that depth where they pass the winter in 

 small oval cells. Their ascent in the spring occurs after the 

 appearance of warm weather and probably some time in earlr 

 May. 



Pupa. Professor Webster records the finding of a very few 

 pupae as early as the first week in June, and Mr Barden states 

 that in 1902 he observed the first pupae at Kipley June 7, though 

 Mr Hough is of the opinion that the larvae began to transform 

 as early as June 4. The great majority of the insects had trans- 

 formed to this stage by June 23. The pupa cells are almost 

 entirelv within 2 or 3 inches of the surface and usuallv within 

 2 or 3 feet of the base of the vine. 



The duration of the pupa stage has been stated by earlier 

 writers as about a fortnight and actual observations with breed- 

 ing cage material has enabled us to determine this period as 

 from 13 to 14 days. These observations were made in the office, 

 where temperature conditions were uniform and father high^ 

 and it would not be surprising if this period was materially 

 extended out doors by unusually cold weather. 



The oval cells occupied by the larvae can be broken with 

 impunity and the grubs will make others, Jbut such is not true 

 of the pupae. The insect is so delicate in the latter stage that 

 the writer has experienced great difficulty in transmitting them 

 through the mails, even with most careful packing. This is- 

 shown by the fact that out of 58 mailed to Albany only 15 

 arrived alive, a number were carefully packed in their cells or 

 laid on moist cotton, otherwise the fatalities would have been 

 much higher. These facts have a very important bearing on 

 remedial measures, as will be pointed out under that head. 



Food plants. This beetle has a comparatively restricted food 

 habit. It was early obs'erved by Mr Walsh on grapevines and 

 the late Professor Riley recorded its feeding on the American 

 redbud, Cercis canadensis. It is also known to feed 



