Table 1. Behavior of apple maggot females of different ages when 

 released individually on a caged apple tree containing a sticky red 

 sphere baited with butyl hexanoate and 50 green or 50 red 

 Gravenstein apples.* 



** 



Values in each column not followed by the same letter are 

 significantly different at an odds ratio of 19:1. 

 Represents flies captured on a sphere before leaving tree or 

 before one hour had elapsed. 

 *** Visits and egg laying before being captured on a sphere, before 

 leaving the tree, or before one hour had elapsed. 



butyl hexanoate, was placed in the upper part of 

 the tree canopy. After the fly was released, its 

 movement was tracked during one hour of forag- 

 ing within the tree. Tracking involved recording 

 all leaves and fruit visited, all oviposition at- 

 tempts and ovi}X)sitions, and whether or not the 

 fly was captured on the sticky sphere. Any finiit 

 iQ which the fly made an oviposition, or an 

 attempt at it, was removed from the tree and 

 dissected to see if eggs had been laid. 



Results 



Fly captures when either green or red fruit 

 were on the tree increased significantly when 

 the flies were more than three days old (Table 1 ). 

 For flies seven or more days old, consistently 

 more were captured when fruit were green than 

 when they were red. Sixty-six percent of flies 

 seven or more days old were captured when fruit 

 were green; whereas, 55 percent were captured 



when finiit were red. 



Regardless of fly age, red fruit received more 

 visits than green fruit (Table 1). Flies 1 1 or more 

 days old were more hkely to oviposit in a frtiit 

 than were younger ones. Interestingly, except 

 for the oldest flies tested, a greater percentage of 

 green fruit than red fruit received eggs. 



Conclusions 



Our results demonstrate that the age or 

 maturity of a female AMF can strongly affect its 

 fruit foraging and egg laying behavior and the 

 probabihty of capture on a baited sticky red 

 sphere. Once a female reached seven days of 

 age, the chance that it would be captured on a 

 sticky red sphere baited with butyl hexanoate 

 hung in our test trees was 50% or better. As fly 

 age increased above seven days, the probability 

 of capture on a sphere did not increase, but the 

 probabihty that it would lay eggs before being 



Fruit Notes, Winter, 1993 



