crossover in drosophila

[John Churchill]

I'm a grade twelve student in Horton District High School, planning on
performing a project on the crossover rates in drosophila.  I was
wondering what traits would be the most advantageous to use.  Also, I
was planning on using temperature as a conrolled variable and was
wondering if there would be a different variable to use which would be
easier to control.  Please help if possible,
thank you,
Sarah