EXPERIMENT STATION REPORT. 



593 



were attached by their beaks, and in some cases so strongly that the 

 mouth parts were pulled out in remioving them from the twig. This 

 was not the ease earlier in the season, when the insects seemed more 

 loosely fixed.. That a much larger proportion of individuals appeared 

 alive on these twigs is due to the fact that many of the dead ones had 

 fallen off or had been removed in some other way. April 18th, more 

 twigs were received from Montclair, with the insects in a similar con- 

 dition. 



Several times during the latter part of April infested twigs from 

 Montclair and Newark were examined and showed the scales to be de- 

 veloping somewhat irregularly, about one-third being alive and ready 

 to move when disturbed. On twigs received April 29th, two distinct 

 forms were found. The one similar in appearance to the hibernat- 

 ing form, but distinctly larger; the other, of the same size as the 

 winter form, more convex and shining. This was, in fact, a parasi- 

 tized form like the old ones found early in the season, although at 

 this date neither larva nor pupa was readily discernible within the 

 parasitized scale. 



May 9th, more infested twigs were examined and a distinct increase 

 in size was noted, as well as the fact that the insects were fixed more 



Fig. 39. 



Scales increasing in size ; to the left taken April 23d, to the right taken May 1st; the 



legs are of the same actual size as in Figure 28, and will serve to show their 



proportion to the developing female ; much enlarged. Original. 



closely to the twigs. The parasitized scales were more apparent, and, 

 on the whole, there were nearly twice as many of these as there were 

 healthy examples. The parasitic larvae were now easily recognized 



38 



