570 NEW JERSEY AGlilCULTLTEAL COLLEGE 



May lOili. — The water was off the bogs, and it was now possible to 

 examine all those patches that had been over water. In every case 

 well-developed larvas were found, and in some cases the largest of 

 these were ready to pupate May 12t.h. On the high ground, along the 

 dams, tips were spun up everywhere, and the yellow head larva of the 

 Teras was noted as being present in good quantity. No close examina- 

 tions were made of the vines on the fully-flowed portions of the bogs. 



May 22d. — Most of the larvae on the upper portions of the bog were 

 in the last stage, ready to pupate, but no pupse were found. On those 

 parts of the bog that had been winter-ilower only an occasional spun 

 tip was found. 



May 31st. — Many of the tips had been abandoned by the larvte, who 

 sought a place to pupate nearer the ground. In a general way it might 

 be said that everything was full grown, in the pupal stage, or ready 

 to come out, and whatever damage was to come from the first brood, 

 had been done. 



June Sth. — All the middle and later stages of the Eudemis were 

 found, and a large number of adults were flying on the bogs. The first 

 brood had matured, or was about to mature, and very little indeed had 

 come from any of the vines that had been water-covered during the 

 winter. Practically, so far as Jamesburg is concerned, none of the 

 vines that were water-covered up to May Sth produced larvae of either 

 the Teras (yellow-head) or the Eudemis (black-head). This is a mat- 

 ter of great importance, as it fixes the dates of development under 

 what may be considered natural conditions. 



The date at which an insect hatches from the egg is, normally, a 

 matter of calendar quite as much as of temperature. A low tempera- 

 ture at the date of normal development retards for a very few days ; if 

 it lasts a week the young are mostly killed. So if the eggs of Eudem is 

 hatch normally on or about x\pril 25th, the larvse will emerge as near 

 to that date as possible, water-covered or in the open air. In extreme 

 cases new larvre of the first brood may be found when adults of the 

 summer brood are already fully developed, but that happens only 

 when the conditions are absolutely prohibitive of earlier hatching. 

 The usual result is that when the normal date comes around and the 

 conditions are not favorable the eggs die instead of developing. 



No date earlier than April 23d can be reasonably assumed as normal 

 for hatching, and it becomes interesting to determine the conditions 

 just immediately preceding that time. 



