Tuesday’s Dave Gram Show begins with a conversation with Molly Walsh of Seven Days on her article asking why three of Vermont’s most densely populated school districts — Burlington, South Burlington and Winooski — haven’t looked at school mergers. Patti Casey of the state Agency of Agriculture stops by to share the latest buzz on mosquitoes and talk about ticks. Later, freelance journalist Mike Donoghue and Alan Keays of VTDigger join Dave to talk about the just completed trial of Steven Bourgoin in the deaths of five teenagers.