Wax on bottom board with no honey indicates other bees have robbed out
after bees were gone.  Mites are still a possibility for  why the bees
themselves left or dwindled to the point of being robbed out.  I had one
observation hive that just suddenly walked out the entrance in early spring
and died but they left some brood.  Evidence would indicate their
departure proceeded brood laying start.
 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+    Raymond J. Lackey                                     +
+    Beekeeper 10 years with 25 colonies on Long Island, NY+
+    INTERNET: [log in to unmask]                       +
+    Mail: 1260 Walnut Avenue, Bohemia NY 11617            +
+    Home Phone: 516-567-1936  FAX: 516-262-8053           +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++