EXPERIMENT STATION EEPORT. 575 



were kept submerged for ninety hours before they were placed in dry 

 quarters. In no case did any pupae develop. 



Based upon previous experience and observations, when, early in 

 May, I found all the Eudemis eggs hatched, I wrote Messrs. White, 

 Budd and Eider, suggesting that the time to reflow had arrived; a 

 conclusion which had been in part anticipated in one case at least. 

 But the results were not at all as co'mplete as was expected. Great 

 quantities of young larvaj were destroyed and were found floating on 

 the surface, but in every instance there was a large surplus remaining 

 that made itself appreciably felt in early July, when the second brood 

 was at its best, or worst. In one case the trouble was admittedly due 

 to uncovered vines in great part; in at least one other that factor 

 was altogetlier excluded, and, on examining the records made by Mr. 

 Dicker-«)n, the probable explanation is that the survivors were those 

 half or two-third grown examples that were lodged between two closely 

 spun-up leaves. All the very recently hatched insects were reached, 

 and all those that were full grown or in the pupal stage probably suc- 

 cumbed to the covering, but those that remained quiet in their shelter, 

 especially in the deeper parts of the bogs, escaped. The probability is 

 increased by the observation that spun-up tips kept submerged for four 

 days rose readily to the surface after their weight which kept it down 

 was removed. The reflowing then, during the early days of May, 

 was too late to reach the half -growth forms and too early to catch any 

 of them in the pupal stage when they are not so well protected. Cover- 

 ing not later than May 1st would have been more effective, because, 

 while all the eggs had hatched, there would have been fewer in the pro- 

 tected stage. On the other hand, allowing the insects to develop until 

 pupation was general would have left very few in the protected stage. 

 That period was about May 30th, and reflowing at that time would be 

 likely to be more effective than the earlier period. 



On the Avhole, the question is now whether, after all, late holding is 

 not the easiest as well as the most effective way to use the water as 

 against the two species of vine worms. 



