Here is a link to the full article:
http://www.jstage.jst.go.jp/article/aez/41/1/87/_pdf
it is important to note that the exposure time changes with the depth of tempurature drop.
to eliminate beetles in any stage of development they must be exposed to the following temperatures at the stipulated minimum times:
Temperature (C/F) -> Min time (Hours)
-20C/- 4F -> 1 hrs
-15C/+ 5F -> 6
-10C/+14F -> 24
- 5C/+23F -> 504
+0C/+32F -> 1,176
+5C/+41F -> 1,680
Note that additional time is required to ensure that the temperature has dropped to such levels at the core of the cigars.
Leave not doubt, freeze and kill the little bastards!