1915] Funkhouser — Life Historij of Vunduzm Arquatu Sat/ 191 



and the petioles of the leaves, the parts of the plants on which 

 they most commonly feed. Feeding may be observed at almost 

 any hour during the day but the most favored time appears to be 

 the middle of the afternoon. The fact that their bird enemies are 

 not usually present during the heat of the day might be advanced 

 as a reason for the activity of the insects at this time. The 

 Membracids do not, however, display any great energy in their 

 feeding movements. They remain in one spot for a long time, 

 seeming to find an inexhaustible supply of sap at each insertion 

 of the mouthparts, and they show little disposition to seek new 

 feeding places. So deeply and firmly is the beak buried in the 

 tissue of the host, and so absorbed do the insects appear to be 

 while obtaining food, that often, in collecting, the mouthparts 

 are broken off and left in the stem when the specimen is captured. 



Ecology. 



Environmental conditions undoubtedly play an important part 

 in the life*history of this insect, and it seems very likely that 

 when sufficient experimental data is available it will be found 

 that many of the seeming irregularities in the periods of develop- 

 ment which have been noted, may be explained by the variation 

 in temperature and moisture to which the eggs and nymphs are 

 subjected. While no definite facts have been secured experimen- 

 tally in the course of this study on the relation of this insect to 

 its environment, several suggestive features have been noted Avhich 

 bear on this phase of the subject. 



The summer of 1913 was the occasion of the worst drought 

 which has been experienced in this locality for many years. 

 Vegetation suffered greatly and the Weather Bureau reported that 

 all recent records were broken for lack of rainfall at the Ithaca 

 station. It was during this summer that the field records showed 

 the most variation in the appearance of the broods of Vanduzea 

 arquata. The early spring of 1914, on the other hand, was marked 

 by unusual precipitation and during this spring the eggs hatched 

 earlier than in former years. In the same manner it has been 

 observed that the nymphs developed more rapidly when the days 

 were warm than they did during weeks of cold and un-season- 

 able weather. As might be expected, also, early springs and 



