8 UNIV. OF N. H. AGE. EXPERIMENT STATION [Bulletin 216 



later than the corresponding date of last year. The length of the egg stage this 

 year ranged from five to ten days. From these eggs the first larvae hatched 

 June 27, which is eight days later than the corresponding date of the same 

 generation of last year. The larval period this year ranged from 25 to 47 days. 

 The last larva hatched this year August 24. It is noteworthy that all larvae 

 that hatched after July 20, representing about 40 per cent of the total, reached 

 only a single generation within the season instead of two. The first pupa was 

 obtained this year July 26, which is seven days later than the corresponding 

 date for last year. The first adult emerged August 9, which is five days later 

 than the corresponding date for last year. 



The progeny of these adults constitute the second generation of the current 

 season. The first eggs of this generation were found August 11, which is one 

 day earlier than the corresponding date for last year. The last eggs found were 

 laid September 26, but no eggs that were laid after September 16 hatched. 

 The first larva of this second generation hatched August 22, which is exactly the 

 same date as the first larva of the corresponding generation of last year. The 

 first larva to reach the fifth instar, which is the stage in which the larvae 

 hibernate, attained that period of growth this year September 18, which is nine 

 days earher than the corresponding date for last year. In other words, whereas 

 the species was late, by nine days, in reaching the adult stage of the over- 

 wintering generation in 1924, its transformations were sufficiently accelerated 

 to place it nine days ahead of the 1924 records at the close of the season. 



A sequence similar to this has been observed with other species and is prob- 

 ably intimately correlated with variations in temperature and moisture and 

 with accumulated temperature. 



The European corn borer is now more widely distributed in New Hampshire 

 than it was in 1923, but has not yet reached sufficient abundance to be found in 

 large numbers in any specific locality. Collections were made at various points 

 in the field through the summer of 1924, but at none of these could more than a 

 few larvae be secured in the course of several hours' collecting. It is presumed 

 that as time goes on the numbers of the species within the infested area will 

 steadily increase. 



In the collections of 1924 no parasites were found attacking any of the stages. 

 In 1923 three specimens of parasites were secured. Up to the present time the 

 species is evidently relatively free from attack by parasitic enemies in New 

 Hampshire. 



The large amount of data that has now been secured through the accumulated 

 records and observations of two years furnishes a valuable foundation of knowl- 

 edge of this insect under the conditions prevailing in New Hampshire. This 

 knowledge should be extended and verified. It is a necessary preUminary on 

 which to base any proposed control measures. 



Studies on the Effects of Fungicides and Insecticides on Plants. 



It is well known that Bordeaux mixture is injurious to certain plants and not 

 injurious to others. During the year studies have been continued by O. Butler 

 (Botany) with a view to determining what effect the composition of Bordeaux 

 mixtm-e had on the injury produced. In general it has been noticed that on 



