162 



TWENTY-NINTH FRUIT-GROWERS' CONVENTION. 



There have been very few observations of the hatching process, and 

 I am not aware that there are any detailed published statements in 

 regard to the process of entering the apple. This is a very important 

 matter in the theory of control of the codling-moth. The usually 

 accepted theory is that the worm must receive a poisonous dose before 

 entering the fruit, or otherwise it is beyond the possibility of control. 

 How the destruction of the worm might be brought about through 

 arsenical spraying was first clearly expressed by Professor Slingerland 

 of Cornell University, who emphasizes the necessity of putting the 

 poison into the blossom cup, in order that the young insect upon 

 hatching from the egg would find awaiting it, in the cup of the blossom 

 end of the apple, a quantity of poison through which it must burrow in 

 order to enter the fruit. Another idea was first brought out prominently 

 by Professor Card, of Kansas, now of the Connecticut station. He 

 observed that the young worm very often ate holes in the leaves before 

 finding the fruit, and his idea, based upon this observation, was that 

 the poison placed upon the leaf and outer surface of the fruit was quite 

 important in the control of the insect, perhaps as much so as that in 

 the blossom end. The observations made at Watsonville throw a new 

 light upon this problem of the theory of the effectiveness of the spray. 

 Contrary to the observations made upon this insect in Eastern and 

 Northern regions, a very small percentage of the insects enter the fruit 

 in the blossom end. Of those that might be classed as entering in this 

 place the majority actually enter the fruit outside of the calyx lobes 

 instead of going within the cup. 



There were a few worms, however, that entered the blossom end and 

 which could be killed by the application made according to»the direc- 

 tions now most commonly given of placing the poison within the cup. 

 According to our observations, the worms live quite a while within the 

 cup before attempting to burrow into the fruit, and will often be found 

 of considerable size and with an appreciable amount of excrement, 

 showing that they have been eating the surface of the cup, and still no 

 trace of a burrow. Apparently they have fed simply upon the surface 

 of the fruit, and have found that the cavity between the calyx lobes 

 offered sufficient concealment to satisfy them and have not, therefore, 

 been forced to bury themselves to secure this protection. This habit of 

 feeding on the surface within the blossom cup furnishes the best pos- 

 sible conditions for the efficiency of the sprays applied according to the 

 accepted idea. The blossoming period in the Pajaro Valley, and 

 probably in most parts of the State, extends over considerable time, so 

 that the first fruit setting on the tree often becomes as large as one's 

 thumb before the tree is out of bloom. Long before this, the cup is 

 closed, so that if the poison is to be placed where it will accomplish 

 this result there must be more than one application, and the first ap- 



