310 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 2 



however, that these conclusions are permissible only in a very broad way, 

 and it must be admitted that in the case of this and other insects thermal 

 constants have not been established with any degree of definiteness. Tem- 

 perature studies of this character, however, are of much possible practical 

 importance, but information is needed on other influencing factors. 



The distribution of eggs on the apple trees has been well determined, 

 involving an immense amount of work. In general, it appears that eggs are 

 deposited promiscuously over the foliage, twigs, and fruit, much the majority 

 of the eggs being placed on the leaves and without any reference to the near- 

 ness of the fruit. 



A distinct advance is made in our knowledge of the feeding habits of the 

 newly hatched larvae, as it is shown by repeated observations that these 

 feed freely upon the foliage, mining into the leaves and boring into the 

 tender shoots. Larvae in breeding cages were reared to maturity on foliage 

 alone, and the author considers that such feeding probably occurs in 

 orchards. This bears directly upon the question of the value of spraying 

 the trees at a time when the larvae are hatching in maximum numbers, as 

 three or four weeks after the petals fall; and also upon the possibility of 

 extermination of the insect during off crop years and in the case of total 

 failures of crop in restricted orchard regions, as has been recently admitted 

 in the Southwest. 



Statistics are presented showing the places of entry of apples by larvae. 

 Records from nine orchards show a variation of from 39 to 77 per cent, of 

 first-brood larvae entering at the calyx end on unsprayed trees, with an 

 average of 65 per cent. Of the second brood larva^, from 22 to 29 per cent, 

 were found to enter the fruit at the calyx end, the average being 46 per cent. 

 This is lower than has been reported by other workers, as by Messrs. Simp- 

 son, Ball, and Pettit. 



The proportion of first-brood larvae which develop to pupae and moths, 

 in New Hampshire, is, fortunately for the apple grower, quite small. From 

 the observations and band records of Professor Sanderson, it is shown to 

 be not more than 3 per cent., and he considers that it may not be more than 

 1 or 2 per cent. 



It is to be regretted that a summary was not given showing the length of 

 the life cycle of the codling moth, as based on the average figures for the 

 respective stages. This may not be computed from lack of data on length 

 of pupal stage of the first generation. 



Under "Experiments in Spraying for the Codling Moth,' a large amount 

 of detailed data is given, covering the work in several orchards during the 

 years 1906, 1907, and 1908. The plan of work, as outlined on page 416, is 

 comprehensive, and it would have been an advantage had the results been 

 briefly summarized in conformity with the outline. 



A schedule of applications of sprays, as based on the work reported, 

 would also have been an advantage, and would doubtless be ap- 

 plicable to the New England states as a whole. Professor Sanderson well 

 points out the desirability in spraying for the codling moth of having plats 

 of sufficient size and of using a sufficient number of trees to avoid possible 

 complication from overflow of moths from one plat to another, and of 

 securing counts from a sufficient number of trees to eliminate as much as 

 possible the individual variations in the percentage of worminess. In the 



