PROCEEDINGS, 1915. 89 



showed fruit worm injury. Further observations showed that the per- 

 centage of fruit worms varied directly with the sheltered location of the 

 orchard. This is no more than one would expect from studying the life 

 history of the insects. They are very active, strong flying moths and are 

 on the wing for one and one half months in the fall, and one month in 

 the spring before they deposit their eggs; and one could hardly expect 

 them to be other than least numerous in the exposed wind swept orchards, 

 and most numerous in the sheltered orchards where they would blow in, 

 and not blow out. 



Controls. 



From following the life history of the fruit worm, it can easily be 

 seen that the time to spray for it, is when it is in its earliest stages, and 

 when it is eating the greatest amount of surface in proportion to the a- 

 mount of food consumed. Actual experiment proves this to be the case, 

 and the two sprays one immediately before the blossoms, and one immedi- 

 ately after, gave a reduction in injury of 65 per cent. The spray applied 

 from ten days to two weeks after the blossoms, gave no reduction in in- 

 jury for the year in which it was applied, but gave a slight reduction the 

 following year, showing that it poisoned the fruit worm after it had done 

 its damage for the year, probably when it was feeding on leaves just 

 before entering the pupal stage. 



Carnivorous Habits. 



During the season of 1913, in collecting the larvae of Xylina bethunci 

 in the field, it was found that the fifth and sixth stage larvae, ordinarily 

 when they find the cocoons of the common Tent Caterpillars, Malacosoma 

 disstria and M. americana, they gnaw their way in through the cocoon 

 and feed on the pupa contained. In 1913, 34.82 per cent of the M. dis- 

 stria cocoons collected on apple, on July 12 and 13, were found to be de- 

 stroyed by X. bethunei. In 1914 the cold season retarded the Tent Cat- 

 erpillars more than the Fruit Worms, which pupated at about the same 

 time as the Tent caterpillar, so only 5.99 per cent of the tents were de- 

 stroyed by them in that season. 



